Saturday, 22 August 2020

SUMMER MUSINGS: The Soundroom - speaker layout, vibration control & correction. (And importance for the subjective reviewer!)


I thought before summer's over, it was time to "shoot the breeze" again and talk generally about a very important topic that affects all of us audio enthusiasts with what I hope are some practical suggestions from my own "journey" here at home.

The image above of a room set-up came from an article back in 1960 entitled Room Acoustics for Stereo by Abraham B. Cohen (Electronics World, January 1960 - make sure to also check out Part 2 here from February 1960). This was a time when many homes were still transitioning from the monophonic single-channel era to the bold new world of stereophonic "3D" playback with an opportunity to virtually experience an actual soundstage in the comforts of the living room. Those must have been exciting times, perhaps comparable in my lifetime to the late '90s with the release of AC3/DTS receivers providing discrete multichannel home theater.

As you can see from the pair of articles, already back in 1960, the groundwork had been laid out for what constitutes conditions for good "stereorama" sound. Best practice tips to achieve a sense of realism, the variables related to speaker placement in a room, angles to target for from the sweet-spot, distance between speakers and orientation like toe-in. Room characteristics like absorption characteristics of materials, reverberation time, room layout were discussed as well; all this informed by decades of professional recordings and studio design that came before.

Heck, Cohen even makes reference to "WAF", the stereotyped concept of the "wife acceptance factor" when it comes to acoustic treatments and aesthetic room layout ("... problems may prove difficult to overcome unless one finds some way of convincing the lady of the house that it is actually her idea to rearrange the furniture, or to hang a drape here or there, or to install acoustic tiles hither and yon"). BTW, over the years, running blind tests asking respondents about their gender, I noticed the ratio tends to be something like 99♂:1♀ in the audiophile world. I noticed that this was the same ratio quoted by Stereophile in their media kit for advertisers!

After all these decades with analogue playback supplanted by digital, the rise of computer-based audio, generations of tube and solid state amplifiers come and gone, physical media transitioning to streaming, etc... the statement "we must look to our living room for the last link in the 'realism' chain, with the aim of bringing it as close to good musical acoustic practice as possible" rings just as true today as it did in 1960. I suspect this is even more important now as the cost of high-fidelity gear has become more affordable and high-fidelity digital ever more accessible!

Apart from near-field and headphone listening and until the day we might have direct-insertion of auditory information into our brains, this statement will remain the most important and likely the most substantial limitation to the quality of audio reproduction we will experience.

Last year, in my "Good Enough" post on the relative contributions of audiophile components, I had already expressed that the "Room" and "Speakers" are really the primary sonic contributors to any system assuming of course that the other components are of reasonable fidelity. These days, DACs, amplifiers, preamps, receivers need not be expensive to be excellent. My feeling is that when we look at the cost of a good hi-fi system then, most of the money should therefore go into the speakers. While we might not think of it immediately, more likely than not, truly the most expensive of all "components" is the "real estate" / room where your system lives and where you enjoy the experience.

So, in the big picture, when we think about the major determinants of sound quality, remember:

1. The Speakers
This is of course obvious and represents a massive topic which I will not take on here other than to highlight its importance. The complexity of speakers is reflected in that the measurements of electronic components are so much easier to read. We can quite easily determine what "good", high-fidelity results should measure like when we look at a DAC or amplifier. Not so easy with speakers!

For example, whereas we can say it's good to have a DAC with low THD+N, we can't as easily look at a speaker frequency response and claim that a single flatter response is "best". We must look at what's happening off-axis, directivity, the relative contributions from various drivers, time domain performance, sensitivity, plus electrical load when matched to amps... All of which a level of magnitude more complex, in essence making DAC and amplifier measurements seemingly one-dimensional compared to how speakers interact with the mechanics of the room and ultimately our biological auditory (and tactile for bass vibration!) system.

Given the importance of speakers, when you are researching products, make sure to spend proportionately more time exploring prospective speakers than amplifiers or DACs.

2. The Room
I love reading and checking out the soundroom photos on threads like this (notice this is Part 15!). It's a nice reminder of all the variations out there in the real world.

Unless one is very well off and owns a mansion with multiple empty rooms, most of us can't just suddenly decide to repurpose a large space or move house simply for the sake of getting larger or better soundrooms! To do so would take massive effort and cost; which is why the soundroom is the most expensive and most "illiquid" audiophile component you'll ever own.

Like speakers, the room's acoustic character is a complex one to quantify especially when the room is not rectangular. Remember the contributions of room dimensions (size, ratios) and what's in the room; whether they diminish sound quality (eg. reflective glass, rattling shelves, table obstructing/reflecting sound between speaker and listener) or potentially improve sound reproduction quality (eg. absorptive fabric sofa, diffractive wall of books/LPs at a good location, thick absorptive rug, specific room treatments). The room will play a large part in what and how much you will be able to hear.

3. System Configuration
Then there are the choices we make in how we allow the System (particularly speakers) and Room interact. Where do we put the speakers? Where's the sweet spot to sit? How are the speakers pointed? Along which wall? How about the equipment rack orientation?

Unless you have a massive room, why bother with proportionately massive Wilson Audio Chronosonic speakers or that huge Göbel at RMAF 2019 if you can't spread them apart adequately or sit far enough back to appreciate a good sonic image? This is an example of the importance of matching speakers to room. Likewise, depending on where you place the system, one should analyze the need for room treatments and targeted "tweaks" to improve sound quality.

Clearly, there is an art and science to how we put those 3 components together. They interact and there are choices to be made to find a high quality solution - likely there will be multiple good solutions.

Reflections on my own room and set-up...

All this is fine and good in theory of course! In the spirit of "show, don't tell", let's get down to business and let me show you what I've done here at home as an illustration. Note I'm not suggesting that what I do is "best". In fact, I can think of a few things more to improve the system but I can say that this has helped my sound quality evolve and at least as of August 2020, it sounds very good and better than August 2019.

Unless one is building the house and has an opportunity to create the "dream soundroom" (see J. Gordon Holt's 1983 article), most of us will have to make due with what we have. For me, I have a basement room that was made for AV purposes when the house was built around 2007 and then renovated in 2013. The floor is concrete with dense engineered hardwood on top. When seated, the left and front walls are drywall over concrete, other walls are drywall with wood frame construction as with most houses in this neighborhood. The rear wall is a bit thicker and I noticed an extra layer of plywood was added behind the drywall and the adjacent room when I had a look during the 2013 renovation. Windows are small, double pane for insulation, and located higher up in the room so they are not problematic reflective surfaces at the listening height. Much of this helps reduce ambient noise getting in.

Ambient background noise is around 30dB SPL in the afternoons and will get lower in the late evenings. Since it's a detached house, there are no worries about neighbours knocking on the door with the subs rocking and rolling. I live on a street corner with reduced road traffic and is part of the city's bicycle infrastructure which helps lower street noise substantially and is very quiet at night. Actually, since there's a park across the street, often at night I hear more coyotes than humans! It's essential that the soundroom be as a silent as possible - from which sonic subtleties can arise of course.

Let's now talk about a few general steps that I've considered in setting up my room plus specific details...

1. There are numerous "How To" set-up instructions out there to review. Consider them as guidelines, no need for rigid rules.

This Dynaudio "Master Class" video provides a great start with some discussion of the golden ratio and others. They also have a room correction video which I think would have been much more powerful with diagrams.

While a number of years old, in less than 15 minutes, Ethan Winer covers quite a lot although I suspect with >30 bass traps in his room, this will surpass multiple WAF/esthetic thresholds for most of us! He also has a 2018 update of his room. I suspect Ethan's choice of electronics gear might be shocking for audiophiles used to much much more fancy and expensive products! This is what it looks like when $$$ are put into room treatments rather than the electronics and I certainly cannot fault him for that logical decision. Check out the website for more.

This short C|Net article from Tom Davenport "How to position your speakers perfectly" is also practical with ideas and general guidelines for speaker-to-wall distancing though the illustrations are mainly for a desktop system.

For much more details, consider buying Vincent Verdult's book "Optimal Audio and Video Reproduction at Home" (reviewed back in April) where he devotes chapters on this and numerous related topics with practical suggestions.

Within the online audiophile world, some of the specific guides for speaker set-up can be found at Audio Physic, Cardas Room Setup, and Wilson's WASP. One of the most detailed is The Audio Beat guide which is nice as it makes suggestions in conjunction with the use of LEDR test signals. Good to review this material to capture the common themes and borrow for your own implementation.

Based on the general guidelines, also check out the Speaker Placement Calculator as a useful starting point to consider by plugging in your own room dimensions.

2. Visualize how you want the system to be generally oriented.

While it's true that experimentation and time will eventually lead to an optimal set-up, in reality let's face it, we don't have unlimited time to fiddle with this and need to get to music enjoyment which is the main purpose! For most rooms, when we walk in and look at where the door is located, where the windows are, I think we already have a good sense of what looks "right" based on some common sense and the idea of symmetry. No matter how good the ultimate layout might sound for any specific room, it still has to be practical and comfortable, otherwise you probably wouldn't enjoy spending time in there!

For my soundroom, there was no doubt that the system was going to look something like this as a logical use of space for 2-channel and home theater playback:


While I can choose what went into the room like the long sofa, absorption panels, large thick carpet, shooting this picture from the doorway, my TV, equipment rack, and speakers were destined to be in that tapered far end. If I didn't do that the orientation would look highly asymmetrical. If I were to reverse the orientation and have the speakers near the door where I'm standing, I'd have to be careful to make sure the door doesn't swing into the speaker not to mention how cumbersome it would be to walk into the room and have a speaker sticking out.

Notice bits of tape at the front which I would use to mark the midline and final speaker positions. A good locking tape measure is an essential tool for the job. Normally, I have a padded coffee table / ottoman placed in front of the sofa for drinks. I've pushed this out of the way - you can see the edge of it at the bottom right of the image.

A tip: 3M Transpore medical tape is excellent for this purpose. It's easy to tear, hangs on to smooth surfaces well and not difficult to remove.

3. Consider sketching out a floor plan to help with layout. I typically settle on a "1/3 + 1/5" orientation in my rooms for speaker placement and prime listening position. 

Over the years, I have had at least 5 different stereo systems at home and rental places I've lived in from college to now. In general, if I were to offer a basic rule of thumb for what has worked for me as a start, it would be simply "Aim the speakers down the long axis, and use 1/3 + 1/5 positioning".

What does this mean?

Here's a floor plan that was sketched out a few months back using Online Room Planner with the guideline overlaid.


Remember the key is to try to keep the room as symmetrical as we can by considering where the midline would be if one were sitting in the eventual "sweet spot". I would have the speakers laid out along the shorter wall, pointed down the longer axis. Since life is rarely perfect, even if slightly asymmetrical as in this room, imagine if this were rectangular as per the light blue filled area. I like the "rule of thirds" idea with the speakers at approximately the front 1/3 boundary from the wall, and the sitting position at the imaginary back 1/3 boundary (the late Harry Pearson advocated for this sensible start point). Distance between the speakers and lateral walls would be about 1/5th of the width using this basic guideline.

From there I start experimenting. As you can already see in my floor plan above, where I ended up putting the sofa and speakers are actually not exactly at the 1/3 boundaries. Remember, this isn't gospel, it's only a guideline. :-)

For full-range speakers, typically avoid putting them too close to the front wall. Likewise, make sure to have space behind the sitting position rather than against a back wall to avoid comb filtering that will muddy the sound; I've seen too many audiophiles sit right against the back wall which is never a good thing. The tapered front wall in my room allows my 75" TV to be set further back, reducing sonic reflections off that large surface. The rear LP rack (and storage) provides a bit of diffusion behind the sofa. If I didn't have that, I would consider getting some quadratic diffusors like these or maybe some inexpensive combined absorber/diffusors for the back wall. These treatments might be good up front if I didn't have the TV there.

So then, here's the "final" floor plan annotated with the items in the room along with some distances and angle between listening position and the speakers:


You can see that I have a couple of GIK Acoustics absorptive panels at the 1st reflection points on each side (discussed / measured a few years back). Of course make sure there are no obstructions between the loudspeakers to listener (especially midrange and tweeter).

Here's a view from the other side of the room:


Notice that I have built-in glass cabinets on that right wall which is why naturally I had to apply some absorption at the first reflection point to my listening "sweet spot". A practical way to find the reflection point is to have someone like your wife/kid/friend move a parallel oriented mirror across the side as you look for the speaker reflection while seated at the sweet spot.

For completeness, here's a look into the back of the room where the LP storage and surround speakers (Paradigm Studio 80 v.3 and Atmos height channels) live:


Notice that this picture was taken with the MiniDSP UMIK-1 microphone set up for room measurements which we will discuss later. Sure, you could do things like sub calibration "by ear", but IMO a measurement microphone is an essential tool that allows you to be more precise and complete across frequencies especially when you're trying to clean up the bass without wasting too much time!

As you can see, the sofa is wider than shown on the floor plan image.

4. Now get the speakers and seating in place as per your envisioned floor plan and start experimenting with the sound - focus first on the front speakers to optimize imaging.

In principle, remember to try to aim for an equilateral triangle which means a 60° angle at the sweet spot between your 2 speakers (or 30° towards each speaker). This is what determines the potential width of your soundstage. Remember to use some basic trigonometry to calculate this (tan=opposite/adjacent is your friend) with just some measurements of the distance between speakers and distance from listening position to that imaginary plane between the speakers.

Notice that for my room, I settled on a 50° angle from listening position to speakers. This came about practically because I wanted the seating position a little further back than an "ideal" 60° angle as I didn't want to sit too close to the TV when watching a movie with the family. Also, there was some trial-and-error experimenting with inter-speaker distance to make sure the central phantom image sounded robust while maintaining wide enough soundstage. An excessively wide inter-speaker distance might leave the centre image weak. I could always lean a bit forward to get closer to the 60° angle if I need to when listening intently.

In concert with inter-speaker distance and the angle with the listening position is amount of "toe-in" to apply for each speaker. Again, there's going to be some experimentation needed. Some audiophiles recommend pointing the speakers at an imaginary point slightly behind the listening position. Each speaker will be a bit different due to off-axis radiation patterns. Over the years, I've found that if the speakers-to-listening-position shape is close to an equilateral triangle, 10° toe-in has worked well for me. I use an electronic protractor to measure this so that both speakers are angled precisely - as you can see with curved speakers like my Paradigm Signature S8's, some estimated "eye-balling" required:

10° toe-in. Convenient to have flooring with parallel lines for reference!
Generally we want to sit with the tweeter at approximately ear-height (unless recommended otherwise by your speaker manufacturer). I have seen recommendations with speakers tipped upwards slightly at the front which might be beneficial for some designs. Certainly if you use desktop speakers, angling them up towards the ears and away from the table surface will be good to reduce reflections. Personally I have not noticed a difference with the speakers I have owned over the years in the context of a soundroom like this.

You might be wondering at this point - "What did you use to fine-tune inter-speaker distance, toe-in, and listener position with?"

Well, you can use the LEDR signals as noted above with the Audio Beat guide. But here's also a simple 3-track test signal I've been using that gets the "fundamentals" done for me:


I know John Atkinson has talked about the use of mono pink noise (-3dB/octave noise) as a way to make sure that the speaker placement and room acoustics are balanced in Stereophile. What I do is similar. Within the package above, you'll see 3 tracks.

I will turn off my sub(s) and any DSP when I play the first 2 test tracks. The reason is I just want to optimize the position of the two speakers without any fancy processing or other sound sources (like the sub) in play.

Track 1 "Dual Mono Pink [Focused] - 20s Fade In and Out" is a mono pink noise that should sound like it's coming straight from the phantom center between your main speakers. Notice that it fades in over 20 seconds, stays at a constant volume for about 50 seconds, then fades out again. Check that during the fades, the image remains centered and stable ("focused"). Spatial instability of the center image would be the result of asymmetry whether of the room or system/speaker issues. Likewise, the pink noise tonality should not change during the fades.

As you experiment with inter-speaker width, make sure the centered sound remains strong. As you toe-in, check that the focus improves into as narrow a central image as possible. Remember that this is a full spectrum pink tone (with proportionally attenuated high frequencies) so don't go nuts with expecting a "razor thin" center image; an identifiably narrow sound located dead center, stable through the fades is what we're after.

Track 2 "Inverse Polarity Pink [Diffused] - 20s Fade In and Out" is a similar mono pink noise but the channels will be inverted in relation to each other. What this results in is a sound that appears to be coming from behind my head when I have my system "dialed in". Again, it should sound centered and relatively narrow in width as well; as if coming from my back wall.

5. Let's check for extraneous vibrations / rattling.

As for Track 3 "Bass Sweep 10-500Hz 30s", because I have quite a bit of glass cabinetry in my sound room, I want to make sure bass frequencies do not excite the glass panels or rattle the shelves (it can be quite annoying!). I haven't seen many people talk about this but it is one of the most common problems I've had over the years whether at this place or in previous homes, so I've always made sure to check for this when setting up.

Basically the 3rd track is a 30 second sweep from 10Hz to 500Hz I'll play at around 85dB SPL usually with the subwoofers on (an SPL meter is another tool of the trade). Listen for any unusual noise emanating from your room and identify where it might be coming from.

For me, in practice, this helped identify a "buzzing" at around 80Hz from the glass cabinet behind my right speaker. Since I did not want to remove the cabinet door, for years I've done other things but recently decided on a simple solution by applying some reasonably stiff polyester fiber acoustic panels. I got some inexpensive black 16"x12" BXI Sound Absorber mounted over the glass with double-sided Scotch mounting tape. This is strong enough to hold the panels in place but easy enough to remove without permanently causing any damage if I decide to later.


Some double-sided tape stuck on.

With the daylight angle above, you can see the acoustic panels placed over the glass. It does the job - no more rattling and also this will improve clarity with less comb filtering as the reflected sound from the right speaker is significantly reduced. Aesthetically while not the prettiest solution, it's not noticeable or distracting at night when I watch movies or listen to my music (wife and kids haven't even mentioned it). I have since moved that old CD rack away from the right speaker as well.

Another possible solution might be to put a foam plug into the rear speaker bass-reflex port (for both main speakers) to reduce vibrations against that rear cabinet/wall but this would also change frequency response of the speakers (and won't work as well as using the absorption panels).

One more thing, Blu Tack (and similar putty) is your friend to reduce cabinet vibrations between the door and frame:


Gratuitous glob of Blu Tack applied, but it works. ;-)

I'll get close to the cabinets and listen for any subtle noises while playing Track 3 at a good volume (~85dB SPL) with my subs active to find out where to apply the Tack. Another tweak that may help is to adjust the concealed hinges to have the cabinet door pushed a little further out if the vibration is knocking the door against the corner along the hinges. This is typically done by turning that deeper eccentric screw where I have the red arrow.

6. "Dial in" the subwoofer(s) now for best bass frequency response.

Now that the front speakers are placed and we should hear good imaging, and bass-induced rattling dealt with, it's time to integrate the subwoofers if you have some. If you don't have a sub, then life is easier. ;-)

There are guides online for placement of subs like this, or this, or this video. With my systems over the years, as in Point 2 above, there really aren't that many places in a room one might want to put a large sub; general placement might just be obvious.

Remember three basic principles highly relevant for bass frequencies:
I. Frequency anomalies are easily audible - more so than time-domain performance. Get the frequencies as smooth as you can.
II. Human ears have difficulty with low-frequency sound localization (<80Hz) primarily due to the long wavelengths resulting in minimal inter-aural difference. For example, the speed of sound is 1100ft/s (~340m/s), so an 80Hz tone has 13.75' (~4.25m) wavelength. Therefore there's little inter-aural phase difference when we consider that the distance between the ears is typically only <9" (<23cm). Feel free to place the subwoofer(s) wherever you like so long as the crossover point is low (~80Hz or less).
III. Below the Schroeder transition frequency, room-speaker interactions are prominent however in small rooms! So while we are generally free to place the subs wherever we want, remember that in a small room, "room modes" will determine what is the best location in any given space. "REW Room Sim" as I showed previously can be a useful tool to help hone in on what might be "better" placement.
Make sure to work with your subwoofer's calibration system if it has one (many subs like my Paradigm SUB1 has a DSP built-in as discussed). I wrote recently about using dual subs which did require a bit of experimentation with a measurement microphone to tweak placement, crossover frequency, phase, and volume for smoothest results (which I've since refined to improve the frequencies below 30Hz). I honestly would find it very difficult to tune a subwoofer well without a measurement microphone (yes, the UMIK-1 is highly recommended)!

At this point with my set-up, with subwoofer(s) integrated, the system sounds pretty good already. With a 1kHz tone set at ~85dB SPL for volume, here's the frequency response in my room with left and right channels:


As shown, there's a typical 15-20dB fluctuation in frequency response in the bass frequencies which you'll see in most small rooms unless highly treated. The measurement was done in REW and you can play with other functions in the excellent software. For example, here's a peek at the "RT60 Decay" function (right channel shown):


That's the decay curve at 500Hz up top. My room clearly isn't in any way an anechoic chamber or highly treated space with the rather "lively" 500Hz RT60 <0.45s - you would see a much steeper curve with more absorption in the room.

We'll have another look at RT60 again below with Acourate.

7. Finally, implement DSP room correction.

As discussed over the years (eg. Acourate filter creation procedure last year), the final step I perform is to measure the room at the sweet spot to create correction FIR filter(s). This really works well for me and I have grown to appreciate the more "neutral" sound in the process.

Here's the microphone in place for AudioVero's Acourate log sweep recording. Using the RME ADI-2 Pro FS R Black Edition as DAC this time:


Here's the "uncorrected" frequency response with some psychoacoustic smoothing applied within Acourate with my soundroom door closed:


Again, no surprise to see a 15dB fluctuation below the Schroeder transition. When adjusting my subs, I purposely tipped the low frequencies higher in volume but not to crazy elevated levels (as listeners we tend to prefer more bass anyway). Remember that it's better to perform EQ with volume attenuation since boosting speaker-boundary nulls is generally unsatisfactory (or even possible).

When it comes to the desired target frequency response, remember that most listeners (myself included) do not prefer a perfectly flat response (have a look at this slide set from Sean Olive in 2009 particularly slide 25 based on Harman research).

I've created various "house curve" options for DSP playback through Roon. Using the "spectral tilt" idea, this time I created "Flat to 20kHz", -3dB, -6dB, and -9dB variants with the slope starting from 500Hz and down by those dB amounts into 24kHz as the target. Here's what the "-6dB Tilt" target curve looks like using Acourate:


After fiddling with some filter creation parameters, here's the final frequency response modeled in Acourate at the listening sweet spot with the "-6dB Tilt" variant which I use mostly:


By now, certainly on this blog you would have seen various graphs like this demonstrating the power of software like Acourate. Frequency response is now within a <5dB range following the target curve at the main listening position. Over the years, I have measured the results within +/-6" laterally and front-to-back from the "sweet spot" to confirm that the frequency response actually does not change that much so there's no need to be concerned that one has to listen as if your head were stuck in a vise!

Here are the various DSP "Tilt" target frequency response curves I can select through Roon presets:

Roon selection through the preset system:


Notice that I measured the room twice, once with door closed then again with it open. Each one with FLAT/-3dB/-6dB/-9dB filters generated, plus I have the "- NO DSP -" option of course. Whether the door is open or closed makes a difference as you might expect for the frequency response, especially for the right channel closest to the doorway.

Given that the speakers have typical analogue crossovers, 2 subs of different brands placed at 2 locations, I cannot expect "perfect" time-domain performance! So long as time domain performance post-correction has improved, I'd be happy... Here are pre- and post-DSP step responses:


A massive difference; impressive what Acourate is able to do here with just a "1-way" 64k length FIR correction filter. BTW, the resultant filters attenuate the volume by about 3dB.

Notice in the uncorrected step response how temporally delayed the two subwoofers are from the main speaker. The little Polk PSW111 ("Subwoofer 2" in the floor plan) is closer to the listening position than the much more powerful Paradigm SUB1 ("Subwoofer 1") which is located in the front left corner producing the lowest bass. Frequencies emanating from the various speakers are now better "aligned" to arrive at about the same time for right and left signals at the prime listening position. Again remember, low frequencies are difficult for the ears to localize so while objectively improved time-domain alignment is good to have, the effect with bass frequencies is very subtle.

Every discussion I've seen on time-domain performance (like this) suggests that we should not obsess too much over it. I certainly would put good frequency response ahead of time-domain performance. Whereas frequency anomalies can be easily heard, time-domain issues (phase shifts, group delays) are not as well resolved by human ears especially given the complexity of music playback.

Finally, let's make sure the listening room isn't overly reverberant. Acourate can do the RT60 calculation for us:


Looks reasonable with RT60 generally <0.5s across frequencies. This is within the tolerances for a DIN 18041 Music space ("music room with active musical performing and singing") of my soundroom's size. Again, this is far from a "dead" sounding room.

If you're interested in standards and specific parameters like RT60 for listening rooms, check out this interesting paper with a table of IEC, ITU-R, EBU, AES, and N-12 recommendations.

8. Now go listen to some music!

Having done all that... Now I grab a beer on a hot summer evening, punch up the playlist of "standard" songs I know well and have a listen. Here are a few example tracks and what I listen for particularly:

- Boris Blank's "The Time Tunnel" (Electrified) with its droning lows - I make sure the sound doesn't excite any glass resonances or cabinets rattling in my room. Soundstage should be nice and wide enveloping you with its "atmosphere". Tons of detail in this clean-sounding synthetic track!

- Rebecca Pidgeon's "Spanish Harlem" (The Raven) maintains a smooth bass line. See here for recent discussion of the notes themselves by Mitch Barnett.

- Deadmau5's "Whispers (Remix)" (The Dali CD, Volume 3) sounds "surround" with the female vocals washing over my head and around the sides into the back of the room when she whispers "I know your secrets". Seductively creepy. Some of the beats have a headphone-like effect as if inside the head. On the same CD is "Moonlight on Spring River". The close-mic'ed Chinese pipa playing by Zhao Cong should sound very clean with precise attacks and you should hear pinpoint soundstage precision for each note. New Age meets Asian vocals and ethereal low bass featured on this track as well.

- Pink Floyd's "Time" (Dark Side...) sounds like I have blaring alarms and chimes ringing around me throughout the room. Each clock/alarm will have its precise place in the soundstage, you should hear some of the ringing as if coming from far corners and behind the head as well.

- James Taylor's "Gaia" (Hourglass) the male voice should sound "present" in the room front and center, with kick ass dynamic percussion waking up the subs and shaking the room at around 4:10. I'm not a big fan of Taylor's hypernasal vocals, but they are distinctive and it should sound that way with the system calibrated.

- Jennifer Warnes' "Ballad of the Runaway Horse" (Famous Blue Raincoat) sounding like Jennifer is singing in my room with a wide, spacious, natural atmosphere with pinpoint positioning of elements like the cricket chirps, songbird singing and subtle effects particularly in the right front soundfield.

- Dave's True Story's "Like A Rock" (Dave's True Story) is another great track to listen for bass smoothness... Make sure no nulls swallowing up any of the notes at the sweet spot! Also a great track to just listen to the "microdynamics" and copious details in those bass plucks. A good system sounds "fast", and be able to easily keep the instruments and voice separated in space, creating the impression of "air" around each instrument/voice.

- Roger Waters' "The Ballad of Bill Hubbard" (Amused To Death) is a great demo of QSound which processes stereo amplitude and phase to enhance the 3D illusion. You should hear a dog barking behind your head at the start, TV channels switching in the distance to the left, electric guitar right in front of you, animal growling, etc... Later tracks like "Too Much Rope" will have a wolf howling in the distance, a horse-drawn carriage travel from front left to rear right across your listening room, a car (Ferrari?) zooming by, and the like. Achieving both accurate frequency and time domain performance will accentuate the believability and clarity of this soundscape.

- Let's end off here with some orchestral music. Telarc's "1812" is a classic for testing dynamic range whether the original recording or the 2001 DSD re-recording. At a reference listening level, do the canon explosions sound clean without nasty distortions from the sound system or room? I've long enjoyed Reference Recording's "The Firebird Suite" (Stravinsky: The Song Of The Nightingale...) and recently their Tchaikovsky No. 4 live performance. Listen to the orchestra... Can you make out the layout of the instruments in the symphony? Does the percussion sound like it's further back? Can you hear the violins in the front and to the left with the cellos more to the right? Can you hear the brass instruments behind the woodwinds, both located down the middle?

If you're a headphone listener, notice that songs with strong 3D positional elements like the Roger Waters' QSound or Deadmau5's "Whispers" will not be rendered with the soundstage as heard with speakers (you can try to emulate the speaker effect with DSP crossfeed or more complex algorithms like RedScape). While headphones have strengths like convenience, portability, relative cost, excellent resolution and freedom from room effects, fantastic with binaural recordings, most of the time I crave the soundstage of a properly set-up speaker system in a good room. :-)

Concluding thoughts...

There you have it folks, I'm very thankful to have a room to call my own - the "man cave" as it were to tweak and tune as I please. There are other things I still could/would do in the future. The most obvious one is to replace the leather sofa which itself is a rather reflective surface; at least the headrest isn't high which would have created even more reflections although that would be more comfortable. The problem is that when the family comes down to listen, we're typically watching a movie enjoying popcorn and snacks... It's nice to be sitting close together and the leather is easy to clean when you have kids with oily buttery fingers! ;-) For now, placing a thick blanket across the leather headrest will help dampen reflections and improve clarity.

Even though most of the time I'm listening as a solitary audiophile, having a comfortable, inviting space for the family is important. Also, when I have friends come over, this quiet room is a nice place to chat and provides I think a "sanctuary" of sorts from the noises and distractions of the outside world. It's all a balance of science, art, creature comforts, and even social considerations, right?

Recently, I read Jim Austin's editorial on audio rooms and I suppose I understand what he means by taking the route of acceptance that no room is perfect. I'm not sure I would be so open to the idea of "seeking" an "authentic room" if it means somehow purposely falling in love with a space that adds evident coloration to the sound though. Let's be honest, this kind of thinking can also be defensive in that he's simply "settling" for what he has. Sure, we should always find adequate contentment in what we have. However, let's not turn contentment into complacency (helplessness?) if there are still ways to move forward and improve what I believe is literally a foundational "component" in the sound system! Aren't "hi-end" $10,000 DACs, $30,000 LP playback, and $75,000 speakers difficult to assess if basic room characteristics are poor with high ambient noise level, the room echoes, frequency response exaggerated, or a skewed soundstage? Just because a room is "authentic" is meaningless if it isn't at least supportive of good fidelity which isn't just about extreme anomalies like "a big honkin' bass mode at 60Hz or 80Hz"! "The perfect is the enemy of the good, the creative, the spontaneous, the real" sounds all philosophical and stuff but again meaningless in that nobody I know is expecting perfection. Anyhow, I would love to learn how Mr. Austin optimized his room with concrete suggestions and ideas rather than just vague opinions without any real-world context. [Let's just ignore whatever he's trying to say about multichannel for the time being.]

I mentioned above the interesting thread showing pictures of rooms and equipment. Great to see forum readers sharing! Since mainstream subjective-only audio reviewer opinions do carry weight for (some) hobbyists, I've often wondered about the rooms that these reviewers use for listening. After all, by now we've seen countless subjective reviewers claiming that (even digital) cables make a difference, "jitter" from digital equipment is audible, that "noise" level can change when listening to different ethernet switches, claims that there are differences between lossless FLAC vs. uncompressed WAV files... If true, these would be very subtle effects and the audiophile must have set up his/her room with utmost attention to detail! Yet how many reviewers actually talk about their soundroom or show us the lengths they've gone through to achieve high quality playback?

I think one of the most interesting series of articles I've read on this is regarding Chris Connaker's "New Listening Room" (Part 1 in 2018, Part 2 in 2019). Fantastic exposé on the lengths he went through with clearly a highly challenging space and the results achieved! I wish more reviewers are as transparent.

2017 was an interesting year for Stereophile as they had videos and write-ups of their reviewers' homes and listening spaces. Jason Victor Serinus' garage conversion in 2017 is good reading and looks like a nice listening space. The video of his room/system looks good but shows us however that he has a certain kind of "faith", "world view" that leads to a desire for Synergistic, Bybee, and SteinMusic products. Videos like Michael Fremer's room/work space in 2017 showed a rather cluttered place - however there was so much breathless talk about cables, claims, personal stories, and gear (including yucky MQA & Synergistic Research testimony) that the camera didn't bother to pan around to show us the listening seat facing those Wilson speakers in that small space beside the boiler room! The Herb Reichert video doesn't even show where he sits or the size of the room either but takes pains to show some kind of artistry, the neighborhood vegetation patch, and feral cats. Likewise the late Art Dudley's video focused so much on the hardware and his bunnies with not even a quick view of that listening room either! How strange. Sure, it's nice to be "artistic" to show the personalities and quirks, but come on... This is about audio, right? Shouldn't we also talk a little about the qualities of the listening room itself since the camera is right there!? I see that Art had an article with a picture of his new place in late 2017 at least.

Elsewhere, Steve Guttenberg talks about speaker placement and agrees that it's all "time well spent" but we don't see what his listening space looks like either or what that "spent time" went into. His relatively short artsy Stereophile video likewise is all about selling hardware apparently again with no regard for the space itself or how those speakers were oriented in the room!

"Audio evangelist" Hans Beekhuyzen even has two videos totaling almost 30 minutes (part 1, part 2) on his "reference systems" but I didn't see a single shot of what the listening rooms look like or discussion of key points about size, ambient noise, room treatments, much less characteristics like frequency response and room reverb he's listening in! Other than for decoration, why does he have all those instruments sitting behind him? Beekhuyzen seems more intent on just introducing products like his network system, NAS drives, streamers, linear power supplies as if these things are all that important (based on typical audiophile boogeymen like "noise" and "jitter" of course). I bet that most people who ask about the "reference system" probably have in mind the question of what the room plus components look like, not just the electronics dissociated from physical space. One cannot help but wonder if this implies something negative about the room(s) if there is reticence to just show us a picture and discuss the real-life challenges of home listening spaces. Fascinating BTW that he keeps insisting that he's "independent thus trustworthy" at the end of videos. Are those things correlated as suggested by the adverb "thus"? I don't think so considering his strange affinity to the nonsensical hype and incorrect advocacy for MQA among other questionable claims.

I dunno about you, but I find myself feeling very unsatisfied watching stuff like this over the years. Surely there must be more that can be discussed, right?

In summary, I hope the room discussions above inspired interest and provided some ideas about optimizing room set-up. I believe that inadequate attention has been paid to this important matter by the media among audiophile writers and reviewers. I know, room treatments aren't sexy and there's little advertising revenue to be had.

Considering that most reviewers in print and online are of the "purely subjective" variety, I believe rooms and set-up are particularly important since the sound quality opinions can only be as good as room conditions allow. Objective measurements need to be discussed in the context of procedural techniques, software and hardware used; so too subjective reviews require context including who the person is (passing "Golden Ear" certification of some sort would improve credibility as well) and under what conditions the evaluations are being done.

Subjective-only reviews commonly have an "Associated Equipment" section that lists everything from DACs, to amps, to snake oil cables, to speaker footers, floor risers, and even bizarre room treatment products! Yet absence of the listening room's characteristics being mentioned renders such a list woefully incomplete. To have more of a focus on the room, discuss decisions made about how the 2 channels were arranged, whether the room is supportive of accurate reproduction, and thoughtful consideration of limitations would I think give readers/viewers a greater sense of confidence that the reviewer truly cares about sound quality; not just an obsession on brand names, collecting hardware (or LPs in the case of Fremer), and basically doing a sales job on hardware products.

While I believe that professional reviews of products is always incomplete without objective measurements, it would be nice to see purely subjective reviewers demonstrating that they're trying to elevate the standard of their listening experience for those reading/watching.

Since technology continues to advance and we can objectively see improvements in both frequency and time-domain performance of all kinds of gear, what Abraham B. Cohen said in early 1960 is ever more important: "we must look to our living room for the last link in the 'realism' chain". I concur.

--------------------

Oh my, how fast the month of August and summer is flying by. Stay safe and have fun with your soundroom, audiophiles. Wishing you fantastic sonic adventures...

PS: When we look around at hi-end audio company product shots, notice how often we see promotional pictures that look like this:


I'm certainly not criticizing the products... I'm sure the Meridian speakers above are fantastic! The point is, I'm just not sure how I'm supposed to feel or think as an audiophile consumer if I see pictures like this. Am I supposed to be impressed by the beauty of these pieces of furniture (notice no speaker cables or power cords)? Does the room appear to be in any way inviting as a venue for good sound performance? It sure is shiny! Am I supposed to feel inspired or aspire to own this product?

Would be interesting to ask the advertising department / product photographer what was the artistic intent.

39 comments:

  1. Archimago! Wow man.

    I only found this blog site last week and going through the posts over the years, I have learned more in this last week than years of the usual magazine articles. I've watched many of the audiophile videos on YouTube and have come to the conclusion that much of that stuff is simply not useful and rather lazy. Much prefer the written word with illustrations like this.

    Keep up the good work!!! I like how you've been commenting on the stuff in Stereophile and YouTube channel reviewers. Critical thinking and speaking truth with facts to this stuff is sorely missing in these days of bite sized headlines and incessant consumerism.

    ReplyDelete
    Replies
    1. Greetings BigPhatStax and welcome!

      I assume your name must have been influenced by the well known headphone maker?

      I appreciate the encouragement. It certainly has been fun putting stuff out over the years. As an audiophile, I got sick and tired of reading much of the same kinds of stuff and ideas in magazines over the years with a paucity of any "meat on the bone" of what these people are talking about. There's only so much an audiophile can take about stuff like "jitter" being blamed for all the inadequacies of digital :-).

      You've raised I think 2 important points here:

      1. There has been a shift in consumption towards video. Looks like videos are able to drive more clicks so some reviewers who are chasing $$$ and/or sponsorship are entering that arena more. I certainly see this shift in consumption towards video content within my own family.

      2. The preference for the written word. While there are benefits to videos as demonstration of or showing off practically how to do something, I personally feel that written articles remain the preferred medium for serious discussions. Over the years, I have shot videos but relatively infrequently unless there is something to show off. The comments section of YouTube videos infrequently contain useful discussions I suspect because once a video is over, there is less of an inclination to engage and most people will just move on. Plus notice that YouTube will automatically cue up another video to "feed" you :-).

      The other thing I like about written articles is the lack of need to find the time-code when we want to review an illustration or be able to quickly scan for information like graphs/charts/diagrams.

      In the long run, it's still all about the content and hopefully bringing something new to the table or at least going over things (like today's post) which I thought needed to be said/shown.

      Have a great summer Stax.

      Delete
    2. Yes, Archimago knows his shit way better than most of those so called expert youtube audiophiles! Thou personally I prefer listening to youtube than read a blog, that way I can do other stuff while at the same time learning things. So Archimago on the tube would be awesome *hint hint* ;)

      Delete
    3. Thanks for the encouragement Tell,
      I'll certainly consider it.

      Lots of work getting the production right though! I'm a bit of a perfectionist when it comes to these things so whereas I feel good enough with putting up static images, getting into the world of video editing won't be much fun for me and time would be an issue.

      Delete
  2. BOOKMARKED AND SAVED for future reference!
    Thank you for sharing, Archimago. Might not agree with everything you say all the time, but you never fail to challenge my believes and understanding in audio science. And often something to learn from you.

    ReplyDelete
    Replies
    1. Thanks for the note iamyuanwu,
      Yeah, for sure! No need to agree on everything! It's good to have varying viewpoints and opportunities to discuss possibilities and work together to find truth. We all will have varying needs and many things in life (and audio) will not be "one size fits all".

      Best regards and happy listening...

      Delete
  3. My main room is 14 X 22 with 7 foot with suspended ceiling 2 x 2 tiles. I have so much stuff on the walls of the room there are few reflections. The room as always sounded good to me and I do have that general downward slope from lows to highs, as does my own personal hearing now at 73. The room does have carpet which helps. My main stereo seat is about 6-7 feet back and the speakers are 3 feet out into the room and 4 feet from the side walls toed in.

    In my smaller office room it is 11 x 11 and it has always been a problem as it is really too small to not have major reflection problems. Most of the time in there I use headphones and have used it mostly to record vocals with an SE Electronics Reflex foam half-circle behind the mic attached to the mic stand. There is carpet and an double bed in the room which helps some with speakers.

    You are right in that many of the speaker photo-shoots you know that no one would ever listen to speakers in those positions.

    ReplyDelete
    Replies
    1. Hi Jim,
      Good stuff. Even though the ceiling and width are multiples, it sounds like you've been judicious in treating the main room.

      11x11 is definitely tight. In my previous house, this was the dimension of the room I was using while the kids were babies - too anxious to have the speakers out in the living room as they crawled around with stick fingers. Actually, my kids were always pretty good - but I definitely didn't trust when their friends came over! ;-)

      Many of the photo-shoots are rather funny. What's most interesting I find are all the ones where there are no cables in sight yet they're positioned as if part of some kind of "system" - especially when there's a rack with components on them.

      All the best!

      Delete
    2. My "judicious" treatments are what my bride of nearly 50 years calls my "hoarding". I am guilty to some degree, but I know that if I sell something, often the buyers does like to have the boxes which I keep out in the garage storage area. I have just managed to keep the reflections to a min., always a good thing. I do love your extensive "science projects".

      Delete
    3. Congrats on 50 years Jim. In this day, it's quite an accomplishment.

      You've got a keeper considering your penchant for hoarding! ;-)

      Delete
  4. Hi Archimago

    A very nice summery concerning the importance of the listening room, together with a lot of useful links worth to read and watch. Great.

    Juergen

    ReplyDelete
    Replies
    1. Thanks Juergen,
      Hope all's well in Germany and you've had a restful time on holiday recently...

      Delete
  5. Hey Arch, great article as per usual :-)

    I am hoping more listening tests are put together for evaluating the time alignment of drivers in a stereo configuration. While I don’t hear much difference between time aligning a mono speaker and listening to that, it makes a big difference (to my ears) when listening in stereo. If using DSP one can try an experiment by correcting both loudspeakers to the same frequency response, but one speaker is “time aligned” and the other is not. The difference in stereo imaging is easy to hear...

    Thanks for linking to my article on “What is Accurate Sound?” There is a diagram on how to read a step response. In addition to the time alignment, as you have discussed in your article, the frequency response, along with the room reflections are also depicted in the step response. Put another way, changes in the step response are directly related to the frequency response, not only the direct sound, but also over time, especially the low frequency room reflections. We can see in your step response that has been taken care of nicely. Also having listened to your system, I can confirm with my ears :0

    Speaking of bass response, as Floyd Toole says, “In the investigation of many rooms over the years, I would estimate that something like 80% have serious bass coloration.” Further, Floyd’s research shows that bass subjectively accounts for 30% of how we judge speakers sound quality. And “ANY loudspeaker can sound better after room EQ, so long as it competently addresses the bass frequencies - this is not a guarantee, but really is not difficult for at least the prime listener.” I am in total agreement.

    Looking at some of the “reviewers” listening rooms, it makes me wonder how many have actually heard smooth, even bass response. Given that the room dominates the low frequency response below the room’s transition frequency and not the speakers, I suspect very few are listening to smooth, even bass response. Unless of course using DSP :)

    Stay healthy and safe Arch, keep up the good writings!

    Mitch

    ReplyDelete
    Replies
    1. Thanks for the note Mitch!

      That would be a great experiment as you suggested to try EQ'ing one side without time alignment to hear the difference that makes. I'll keep that idea on the list of things to try in the months ahead :-).

      Hope you're enjoying the weather and staying safe also! Keep up the great work and come on over when you're in town :-).

      Delete
  6. If the speakers can't be kept properly away from side walls (>=1m) then first reflection treatment is recommended, otherwise it isn't mandatory in my book (though it depends on the room and construction).

    Right, room modes vs SBIR ...

    For SPEAKERS, close to the wall behind is ideal for many rooms. This gives a more correct SBIR - see 'Wall Reflections and Cancellations' at https://www.genelec.com/monitor-placement. This is probably a more key consideration than room modes, when comes to placing the speakers. So if "1/3 into the room" places the speaker baffles in the 0.6m to 2m range from wall behind, I'd consider placement like in the Meridian picture. I wouldn't be so harsh on that photo.

    More crucial for managing the effects of room modes is the placement of LISTENERS away from room boundaries. Here we are in broad agreement.

    PS: Most complaints about imaging suffering when placing speakers close to the wall behind, are more likely related to large objects in the vicinity, such as hi-fi racks, television, furniture, fireplaces etc. and not the wall itself. Consider the Meridian photo: just active speakers with against a plain wall, the hi-fi rack etc. is elsewhere. I use the same arrangement. Which is why, considering the logical extreme, soffit mounting works well.

    But yes if instead you have a bunch of objects in that area of the room, then speakers sitting forward of them is a good idea. According to the information explained by Genelec, speakers should then be kept at least 2m from the wall behind.

    ReplyDelete
    Replies
    1. (I agree there are still some problems with the Meridian photo, such as the highly reflective floor!)

      Delete
    2. Great comment, thanks Darren!
      That Genelec link is a great read. Hmmm, I'm curious now to try pushing the main speakers closer to the wall and seeing if this changes my bass/low-mid frequency response. The fact that my wall is angled already probably shouldn't be as much of an issue compared to a straight reflection.

      The thing that gets me about the product image is when there are simply no wires to be found ;-).

      Delete
  7. An aside: If you have something like an LG OLED 4K 75" TV, you're TV is way too far from your seating. I don't think this article's distances are off by much (from personal experience): https://www.forbes.com/sites/kevinmurnane/2018/11/24/got-a-black-friday-4k-tv-heres-what-you-need-to-see-all-that-4k-goodness/#783861f85b93

    ReplyDelete
    Replies
    1. Hi Jack,
      Yeah, if we want to optimize the spatial resolution of the 75" 4K TV to see the difference between 1080P vs. 4K, then definitely it's as you noted and as per the article, I should have the screen closer. As it is, my sitting distance is about 10' which is the recommended for 1080P screen and that's comfortable rather than optimizing potential resolution.

      I love watching 4K movies still, however generally it's the HDR effect that makes the most difference and that's of course noticeable at 10'.

      (I actually wrote about this awhile back around angular resolution and such:
      http://archimago.blogspot.com/2015/03/musings-gone-4k-uhd.html)

      Delete
  8. Nice mix of science and science fiction ;-).
    And still no 1m "speaker" measurements of the loudspeakers showing the damage done by perceptually blind "room" EQ.
    Ah well...

    ReplyDelete
    Replies
    1. Sure, it'll come at some point AJ.

      Got a few other things I need to do first. Considering I'm listening in my sweet spot at a certain seating height, with a certain toe-in and with different room effects, I'm not sure what's the point. I don't expect the frequency or time performance to be "good" at 1m...

      Here's a thought AJ. Do you have a write-up and pictures of what your room and set-up looks like and even better yet, with what objective techniques you've used to assess/optimize the sound quality? Would love to learn from your work.

      Delete
    2. One more thing AJ,
      Are you with Soundfield Audio?
      https://soundfieldaudio.net/

      Interesting products and I see the positive show responses... I didn't see any suggestions or ideas on the website about speaker placement or "how-to" optimize one's listening space. I'm sure customers would be interested and it would be helpful for audio enthusiasts!

      Delete
    3. Hmmm, I think you misunderstand. The 1m on/off measurement is to see what the "speaker" is doing, nothing else. I don't know of any meausrements of your particular model on web. That means, no "room eq", etc. engaged. Just the raw/native response. It's an older Paradigm, so it should be relatively flat/smooth on/off axis, as was their practice at one time. That is predominantly what your 2 ears hear >500hz or so. As I mentioned to you previously, speaker rankings remain consistent over various rooms...for a reason.
      Then engage your "Room eq" elixir curve that made the omni-mic happy at your seat and eyes seeing that uber cool looking straight sloped graph ;-).
      Compare the two. Should be interesting, as illustrated here:
      https://www.avnirvana.com/threads/looking-for-suggestions-for-graph-metrics.6973/#post-51900
      Yep, that's (Soundfield Audio) me.
      Websites a mess, need to spend far more time on it ;-).
      I'm inching closer to completing my new measurement turntable so that all posted measurements are standardized, not a mish mash. That's the priority.
      "Optimized" room setup? Hah. There is no such thing (and that certainly wouldn't include 2" absorbers at first reflection points!!)
      https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation
      I can and do advise customers on placement of course. But ultimately it's not what I prefer, it's what they do! Yes, including 2" absorbers at first reflections, etc.

      Delete
    4. Hi AJ,
      Hmmmm the Signature S8 v3's were in production until about 2015 I think so it's not *that* old! Sure 1m measurements are fine and could help differentiate preference of speakers given a standard room like at the NRC. Just because speaker rankings might be consistent within those studies does not mean that for any and every room, we can't improve things with the EQ, does it?

      I saw that post of yours at AVNirvana awhile back. So? Since you feel strongly about this, I suggest you update the website with your speakers and discuss the technique for all to learn from! That's the best way IMO to educate and give to hobbyists...

      BTW: Would be great to see the graphs for your speakers as well!

      Delete
    5. "Signature S8 v3's were in production until about 2015 I think so it's not *that* old! Sure 1m measurements are fine and could help differentiate preference of speakers given a standard room like at the NRC."

      Wow Arch, for someone who does otherwise great non-acoustics work, that's a pretty convoluted "audio forum" knee jerk type response! lol
      Jeeez, the "older" is a compliment! The Paradigm S8 v1 measurements I linked showed a superbly smooth ANECHOIC on/off axis, i.e. a "preferred" by TWO EARS curve.
      Compare that to "newer" >2015
      https://www.stereophile.com/content/paradigm-prestige-95f-loudspeaker-measurements
      https://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=2124:nrc-measurements-paradigm-premier-100b-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153
      What has happened? The S8v1 response is "bad news" if (your) V3 looks more like those, or..if it looks more like the V1..and you've destroyed the preferred by 2 ears response with your preferred by 2 eyes and a pressure mic "room" curve/tilt/B&K/Harman/whatever severely misguided "target" EQ.

      "Just because speaker rankings might be consistent within those studies does not mean that for any and every room, we can't improve things with the EQ, does it?"
      Huh?? The "consistency" shows the >500hz "preferred" NATIVE response remained regardless of the quite varying room..and room acoustics.
      You still don't understand the difference between what 2 ears hear vs a omni mic?
      Hard to believe if you've read "Toole" aka perceptual science knowledge as of today.
      Nice yet another audio forum type red herring. What I posted on AV Nirvana has zero correlation to "the technique" or anything related to my website.
      Once the TT is complete, I'm only going to be posting quasi-anechoic 1m on/off axis. Using REW. 1/6th octave and maybe with psych smoothing. Something you seem to have disdain for?
      Puzzling to say the least.
      You honestly don't get what the AVN link shows about measurements vs (controlled) perception??

      Delete
    6. Hmmm AJ,

      I think sometimes in forums/messages we miss out on the non-semantics of communication and your style of "talking" is for me rather difficult to follow and emotionally charged. For example how am I supposed to interpret your comment about the "older" Paradigm if in fact it was in production in 2015? I actually didn't take it as an insult but just brought up that it's not "*that*" old compared to say the V1 measured by SoundStage! in 2004 so does your "compliment" really have the same meaning?

      Even if we read the same papers and books, application to real-life and determining what we read will have different levels of significance. Furthermore, I'm not sure why you question that I have a "disdain" for psychoacoustic smoothing; that's a rather strange and emotionally charged claim when in fact all the Acourate graphs in this post above were psych-smoothed. To say I have "disdain" suggests that I "hate" something which I don't - doesn't that make your comment rather unpleasant to read when you attribute an emotion to someone? Ever thought that maybe the way you communicate actually projects the "audio forum knee jerk type response" which you do not even realize because you're goading them into defending themselves against a charge which simply isn't true?

      Anyhow, look, enough with the bits and pieces of links to this and that you feel you fully understand. I suggest you go create some content on your website given that you are a speaker designer and show us what you do and put up some 1m graphs yourself. I'll get to my system in time. I'm sure there is much I can learn from you so by all means, educate with some practical examples given that you have the tools and understanding...

      One more thing. The EQ'ing and smooth tilt graphs above 500Hz for me isn't the big deal. Again, you insist that my "eyes seeing that uber cool looking straight sloped graph" is of great significance to me. It actually isn't. Since when did I place much emphasis on the treble shape other than agreeing that it should be tilted down so it doesn't sound too harsh in many recordings? In other posts I've talked about the "BBC Dip" as well. Even though the house curve is audible in adjusting the amount of "brightness" to the system, the bass smoothness is more significant. And since I'm listening in stereo (this is not an exercise in mono speaker listening and rating which sounds better as some of the test methodologies I believe used), having the 2 sides be EQ'ed to the same target so the levels are very closely balanced across the frequencies is also the more audible effect for me.

      Delete
    7. "I'm not sure why you question that I have a "disdain" for psychoacoustic smoothing"

      Ummm, no, *1m* "speaker" measurements, like the several I've linked. Yes, I know the NRC uses 2m, for good reason, but neither of us have that option in our setups. Hence 1m. That should be fine for >500hz. On tweeter axis. 0,30,60 is fine, like I've temporarily added to my "M3C" web page.

      "The EQ'ing and smooth tilt graphs above 500Hz for me isn't the big deal."

      Umm, except it IS, because without the quasi-anechoic 1m as a reference, it's completely "blind".
      You're still not getting "Toole", Olive or the significance of the ANV *2 ears* results??

      Delete
    8. Btw, out of curiosity, what do you think Olive means by "The Direct Sound" in the quote I linked from the "Target Curve" study?

      Delete
    9. Let's bring together the discussion and summarize this in the latest post below...

      Delete
  9. It seems there are valid anechoic measurements of the S8..v1
    https://www.soundstagenetwork.com/measurements/paradigm_signature_s8/
    If yours measures anything like that, that's bad news.
    And you really need to read the comments of the Olive test you linked and have badly misunderstood. http://seanolive.blogspot.com/2009/11/subjective-and-objective-evaluation-of.html
    FIRST comment:
    Dr. Sean OliveNovember 2, 2009 at 10:33AM

    In truth, the optimal in-room target curve may depend on the loudspeaker directivity and reflectivity of the listening room. If the room is acoustically dead with few reflections and/or the directivity of the loudspeaker is quite high, the in-room response will represent a higher proportion of THE DIRECT SOUND, WHICH SHOULD BE FLAT. Using a target curve with large downward tilt will make the loudspeaker sound too dull.

    Ooops. It's impossible to know what you direct sound is without 1m/quasi-anechoic "speaker" measurements...I've been suggesting.

    Oh and:
    Dr. Sean OliveNovember 4, 2009 at 9:21 AM
    The JBL LRS6332 is the standard loudspeaker playback system in all of our Harman Reference Rooms located in Northridge, Farmington Hills, UK and Germany. All of these rooms are equipped with the Harman room correction system described in this paper. Since the JBL LSR6332 is already a good loudspeaker, we are mostly doing room correction at below 300 Hz. We also use Sound Field Management applied to four subwoofers in the corners, which largely takes care of the odd order modes. Because the LRS6332 has well-behaved direcitivity we have the option of equalizing its direct sound without adversely affecting its sound power response, and vice versa.
    Room correction will improve poor loudspeakers like the ones you have indicated, but why put an expensive bandaid on a scab if you can easily avoid getting the scab in the first place?

    ReplyDelete
    Replies
    1. Hello again AJ,
      The S8 v.1 measurements are rather old and what I have seen are quite different on mine. Anything in particular you like to see or are concerned about with the v.1?

      Again man, show me what you got and how you're doing this! Go ahead, show us how you would use your own speakers' 1m/quasi-anechoic measurements in your room to improve the sound. Show me your room and what acoustic treatments you're using. If you do use EQ of some sort, what is it and how do we get the job done?

      All nice and well to quote Olive and his JBL speakers in the "Harman Reference Rooms", but I'm talking about my smallish soundroom in the basement, man and some techniques to get the job done that's pretty good for me - with options on the "tilt" (so I can adjust to music to make sure the sound isn't too dull). Plus of course some music recommendations to consider using for listening to the sound quality. Where's your content other than quoting the work of others?

      Like I said at the beginning of the post - "show, don't tell". Show me what you got and how you're doing it. Otherwise it's hard to assess what value your comments may or may not have. You have a platform already...Put your website to good use and like I said in the previous post - where are the measurements for the speakers you build!?

      Delete
    2. How would you possibly know how your V3s compare to the V1 without (quasi) anechoic 1m +/- measurements?

      Amir, excuse me, Arch, what would my 1m measurements have to do with yours, your room and EQ, "treatments", etc...unless just an Amirish type red herring deflection?
      Remember how Toole is only trying to sell Harman speakers with all "his" studies? You ought to be familiar with these type Audio forum "counter" "arguments". Perhaps Amir has taught you something ;-).
      To address your point, I would/do exactly as "Toole/Olive/et al" aka perceptual science suggests. Design the speakers with as flat/smooth direct response, so nothing needs to be done >500hz. No elixir EQ. No iso-ward "treatments"...unless needed by user (vs speakers/ears).
      As far as the <500 "room" bass, use EQ for judiciously cutting peaks only, based on multipoint measurements around head listening seat.

      Oh boy, now Olive's results (which you reference!) don't apply to you/your room?
      Pray tell, why then would "my" results/measurements in "AJs room" matter one iota?..unless...oh yeah, Amirs audio forums type teachings are having an effect! ;-)
      For that, I must give him credit. Look, look over >there lol

      Delete
    3. Greetings AJ,

      Fascinating thought process man.

      While I am of course aware of Amir's site and his work, I'm not aware of my thinking being highly influenced by the site since I don't visit often other than reviewing some of his measurements to help correlate my results with what he finds on the AP gear. Also, interesting reading the perspective of some of the participants when I review items like the Pass ACA recently.

      Okay, so you don't think results/measurements and treatments in "AJs room" could be helpful to others, or perhaps could teach others with your own example. You seem to think this is a deflection tactic me bringing it up. I disagree of course since I think it would be beneficial to actually see and understand what room set-up looks like in actual practice and with the limitations of space and room characteristics. I personally would find that more interesting these days than yet another vague subjective review or even just plain measurements of electronics. Furthermore, this will add symmetry to the discussion so readers can compare and contrast what I'm doing here with your thinking and how it would manifest in practice.

      So why don't we just focus on the main points of your critique:

      1. You don't like the room DSP as implemented in the post. Doing this would not be helpful and could/would harm sound quality.

      2. The omni measurement microphone placed at the listening spot does not correlate with human hearing. Achieving a flattish or "house curve" response like this might be appealing to the eyes but is inaccurate and may even worsen sound quality. It does not follow what Toole/Olive is writing about.

      3. The Toole/Olive work including the target curves >500Hz are only applicable to direct sound (for this we need to review the [pseudo]anechoic data for the speakers) - this is thus a reflection of the speaker design. EQ'ing is therefore not beneficial. (It appears then that the end-user's options are limited short of buying better speakers.)

      4. You would only apply EQ to <500Hz or so to cut off peaks. Use spatial average instead of single-point measurement.

      Are those points basically correct then AJ? Encapsulating your viewpoint on the flaws of the method and generally what you would or would not do in your own set-up?

      Delete
    4. 1, Correct. Good speaker, aka high possibility your S8v3, JBL LRS6332, et al...NO EQ > 500hz +/-, unless a) Tiny tweaks to anechoic on/off to maximum flat line b) "tone control" for individual recording, i.e. not fixed. A "tilt" like preset, somewhat like what you've done, but NOT based on the blind "room" curve.

      2. Correct again. See **subjective double blind ratings** from "anechoic vs room flat" https://www.avnirvana.com/threads/looking-for-suggestions-for-graph-metrics.6973/#post-51900 , Toole's book, AES, etc

      3. Not quite...if you are citing the "Room Correction" http://seanolive.blogspot.com/2009/11/subjective-and-objective-evaluation-of.html
      The >500Hz EQ WAS beneficial to the poor speaker. The "flatish" slope correction AT THE LP was indeed the most preferred of the "Room" eq/correction products. However, there are caveats. a) None were tested vs the "anechoic" EQ'd speaker like the AVN link, because of course, none of the room eq products do that. Its not specified, but that AVN anechoic eq was most likely done manually. Best way!
      b) There was no separation of the <>500hz. It is known that fixing <500hz ALONE, aka cleaning up the bass, can have a dramtic effect on perception >500hz.

      4) For stereo with 2 monopolar speakers, yes.

      For HT, electronic mostly monophonic bass music, multi monopole subs + EQ.
      Or gradient bass (cardioids, etc). And/or passive mid bass trapping. Quite a bit "depends" here.

      Lastly, I know of no studies showing the benefits of 2" absorbers at first reflection point...worse, with smooth off axis speakers..most likely, like your S8s. I do know a mountain of evidence showing what listeners, including absorb everything in "sight" studiophiles, prefer with 2 ears. Toole et al again.

      Delete
    5. http://seanolive.blogspot.com/2009/11/subjective-and-objective-evaluation-of.html

      Dr. Sean OliveApril 20, 2010 at 5:41 PM

      Finally, if you own Revel Salons, they don't need any equalization except below 300 Hz where the room dominates what you hear :) If you own good loudspeakers, you should focus on correcting the low frequency acoustical interactions between the loudspeaker and room.

      Delete
    6. Thanks for the note AJ,
      Let's continue this conversation when I get some 1m measurements up in the days ahead. For sure it's coming...

      Remember the main reason why I have those 2" absorbers to either side. It's because of the severe asymmetry in the room with the glass cabinetry on the right! Without the absorption, certain frequencies hit a resonance and I can hear a faint rattle. The panels prevent this from happening plus there's a sense of better balance...

      Delete
  10. Bravo Arch! Love how you respond to people like AJ Soundfield. For a guy who writes like that about speaker measurements, you'd hope he actually had more to say on his website and about his speakers.

    To your question above, yes, I'm the happy owner of a pair of Stax SR-L700 MK2s. Truth be told, I still prefer listening to speakers at home when I can. I live in a condo so there are only so many hours in a day wherre neighbors don't complain!

    ReplyDelete
    Replies
    1. Thanks for the note Stax.

      I haven't tried those specific headphones but I certainly have enjoyed listening to Stax gear over the years when I've had the chance!

      I feel your pain with the comment about living in a condo. For 7 years through the end of university and into the first couple of years working, I was in 3 different apartments. Challenging with space limitations for the sound system and of course the issue with neighbours... I remember one place where the lady upstairs would complain about my music at 8:00PM but some nights would come home at 1:00AM sounding like she's walking in tap-dancing shoes.

      Definitely high quality headphones are essential at times! ;-)

      Delete
  11. If only I had the space...
    No way am I going to play music along the length of my room. In one corner there's a door (which is a definite no-no in my book) and in the corner next to it, an open space.
    In the opposite end of the room two large glass panes, another door and another open space. Absolutely not going to place speakers in those positions.

    So, I chose to play from a long wall to the opposite long wall, which means 8½ feet tops from the front of my speakers to my ears, but I can live with that much easier than to involve doors and open spaces and doors close to my speakers.

    Apart from that, my speakers are 2-way stand mounted, quite much toed in, because they are a little too far from each other as it is now. This will be remedied later on though.

    Here's a crude drawing of my listening room, which measures about 5½ meters x 3½ meters, and a photo of the equipment and speaker placement. It is not ideal, but the sound is absolutely awesome as it is.

    Drawing: https://drive.google.com/file/d/1B0sF1B3UBnMLL6gXzynNPh9JzEKk6wqB/view?usp=sharing
    Photo: https://drive.google.com/file/d/1gj898TQ4aXimpoEb3wRtQ0p3ByjFPFLF/view?usp=sharing

    There are many roads to satisfaction :)

    ReplyDelete