One of the joys of writing an audiophile blog is the opportunity to meet some interesting people in this hobby over the years! Here in Vancouver, there's no audiophile special interest group or club I'm aware of. As a result, connections are made through receiving E-mails or private messages once awhile by locals to hang out, check out gear, and listen to tunes together...
The big speakers are the Avantgarde Acoustic UNO 2.1 horns (see Stereophile review here) with active bass modules from around Y2K. Sadly, pictures really do not do justice to the fit and finish of these speakers! Gorgeous gleaming metallic deep blue on those horns.
As you would imagine, these horns are very sensitive transducers. We're talking something like 101+dB/W/m. The bass module is the SUB225 CTRL PRO consisting of two 10" drivers and there's a 200W Class AB amplifier in the box.
The picture above from the side also gives us a peek at his equipment rack behind the speaker. For analogue source, he's using the Linn Sondek LP12 turntable powered by a Radikal, and the EAR 324 phono preamp. Cartridge is a denuded Linn Akiva moving coil.
On the digital source side, we have the Linn Klimax DS streamer, a Rotel CD player and I see he has been doing some vinyl rips with a Benchmark ADC1.
All of the sources are fed into his tube Manley Jumbo Shrimp preamp and then into a rather rare Pass Labs First Watt SIT 2 (not shown) using the "Static Induction Transistor". The SIT 2's manual states that the distortion at 1W is 0.7% and it can push 10W at 5% THD with a 1kHz signal into 4Ω; not exactly the typical specs a pure objectivist might be impressed by :-).
|Notice that he also has a McIntosh 275 amp in the bottom rack - not in use at the time.|
Let's measure that Avantgarde UNO 2.1 system!
This is all well and good of course. We could all hang out at a friend's place, grab a drink, listen to some music, and shoot the breeze for hours... But since we are both curious and "men of action" ;-), let's see if we can learn something about this gear, the room and maybe improve the sound!
I brought over a little measurement kit consisting of my Focusrite Forte which provides DAC and ADC capabilities plus functions as a microphone preamp with phantom power. A calibrated microphone is a must so I brought over the Dayton Audio EMM-6. The Microsoft Surface 3 Pro laptop has a bunch of software including REW and Acourate installed. And a microphone stand.
The first thing we measured was the main system to see if we can get the Avantgarde frequency response optimal. Here's how the frequency response was like at the best listening position from the sofa when we started:
That's with the UNO speakers only, REL sub off. Not bad at all! Bass is already full and music already sounds great (I brought over some Leonard Cohen and Daft Punk which I was familiar with).
We then turned on his REL sub and the REW measurements showed some significant destructive interference between this and his UNO (alas did not save those measurements as we fooled around with the settings). To put a long story short, we ran through a few settings with the REL, flipped sub polarity a few times and checked channel effects, subtle positional changes, tested channel balance, and adjusted volume settings to come up with this "final" frequency response at the listener position:
As you can see, my friend wanted his bass powerful and deep with the portion below 40Hz filled in with the REL. At 20Hz, the SPL has been boosted between 10-20dB with the REL sub turned on. Obviously, he can vary the sub volume to preference if that becomes overwhelming.
We can also look at the time-domain with a peek at the step-response captured by REW at the listening position over 5ms; remember this is in-room response, no special correction, with no attempt at semi/pseudo-anechoic response:
|You can compare this with Stereophile's measurement. Notice that the polarity is inverted here.|
Here are some off/on digital filter results:
Looks good and should sound good :-). I'll leave it to my friend to adjudicate the subjective sound quality of course...
Ohhhh... Look at those monitor speakers!
As we look around his room, we see a number of other speakers he's having fun with. For example he has this Tannoy Reveal 501A (predecessor to the Tannoy Reveal 502) sitting on top of an Omega Maxhemp (8Ω, 35-18kHz, 96dB/W/m) based on single crossoverless Alnico 8" driver with whizzer cone:
And he brought out his new not-broken-in KEF LS50 just out of the box and had an old 1976 Spendor SA1 that still sounds in reasonable shape as well:
For fun and comparison, we stacked a few sturdy boxes with stuff inside, and put the small speakers on top. We placed the microphone almost exactly 1m in front of the speakers and also almost exactly 1m above the floor - like this with the mic on-axis to the tweeter:
Between the Spendor and KEF, there are at least 35 years worth of evolution in speaker design, material science, and electronics for the crossovers! Here is a frequency comparisons of the little speakers overlaid (1/12-octave smoothing @ 1m, on-axis):
The Tannoy Reveal 501A is an active studio monitor meant for nearfield use. A few years back before discontinued, it should be comparable to the current price of the Reveal 502's at <US$300/pair. Notice the high frequencies are a bit accentuated even with -1.5dB "HF Trim" setting on the back. This kind of rising high frequency response on-axis suggests that they were designed to be listened off-axis (like maybe 30-45°) where the response should be significantly flatter. Time permitting, it would have been good to grab a few off-axis curves to see at what point the FR flattens out. Here's a good Sound-on-Sound review of the 501A's with 5" woofer and 1" soft-dome tweeter. Notice the bass response is quite good with extension all the way down to below 40Hz. As an active speaker, the company has the benefit of controlled matching of amplifier(s), drivers and crossovers.
The other two passive speakers (KEF and Spendor) were measured with the Pass SIT 2 amplifier and Manley Jumbo Shrimp preamp for volume control. Of the two, the modern KEF LS50 (circa 2012 release, price lowered to ~US$850/pair now and great deal at CDN$900 currently) is more neutral up to 20kHz and we can see the frequency extension into 30kHz with possible tweeter resonance out at 40kHz. This is a "Uni-Q" coaxial speaker design with 5.25" woofer with 1" aluminum tweeter.
Finally, in blue, we see a truly classic speaker; the Spendor SA1 from a few generations back still looking in decent shape ;-). (Initially, I thought this was their also-classic LS3/5A.) This speaker was designed by Spencer Hughes for BBC mobile monitoring and said by a number of folks to be superior sounding to the LS3/5A. It's a 2-way design, has a 6"/150mm "doped Bextrene" mid-bass cone and 3/4" tweeter. Bextrene is a plastic used back in the day primarily in the automotive industry and apparently an ingredient in plastic grocery bags, a precursor to polypropylene. It is rated as 8Ω nominal impedance, and has its crossover point at 3kHz. I don't know the sensitivity specification for the Spendor, but with the same volume gain applied, measured amplitude is lower than the KEF LS50 (which is rated as 85dB/W/m). In this measurement, we see a bit of a dip just below 9kHz. This seems to be too high in frequency to be the "BBC dip" or "Gundry presence dip" folks have talked about over the years which tends to be down around 3kHz (close to the crossover frequency). Not sure if this 9kHz dip is just a quirk with this box. Will need to check the other one to look for a match next time.
Clearly there are differences between the KEF and Spendor but perhaps not as much as one might imagine given the 35+ years age gap based on just these on-axis frequency measurements! But there's more, we can see significant differences in the time-domain step response (5ms window):
|NOTE: With further examination in more detailed tests, I found that these impulse responses were inverted. See the Spendor SA1 measurement for example.|
Hmmm, looks like there may be phase inversion in the Manley preamp or SIT 2 amplifier (suggested also by the Avantgarde measurements above). The polarity is flipped on the KEF LS50 graph compared to Stereophile's measurements a few years back. We can see the temporal "quickness" in the LS50's driver design with smooth integration of tweeter and mid-bass connected in opposite polarity whereas both the Tannoy and Spendor have tweeter and mid-bass drivers connected in the same polarity. Maybe next time I'll double check on the "absolute polarity" bit to see where the inversion is happening (the SIT 2 amp inverts, but my friend believes it was accounted for). As usual, due to questionable human ability to sensitively perceive phase/temporal information, frequency response appears to be much more important.
Finally, while tube preamps and the Pass SIT 2 amplifier may add quite a bit of harmonic distortion themselves, we can still compare the KEF LS50 and Spendor SA1 to examine the distortion signature through the same preamp/amp combo:
A bit more low bass 2nd order harmonic with the Spendor. Interesting frequency-dependent excitation of higher order harmonics below 200Hz in both speakers. What looks much improved is the reduction of high-order harmonic distortion in the treble with the newer KEF LS50.
While each of us will have to listen for ourselves to determine preference between a vintage speaker like the Spendor SA1 vs. modern KEF LS50, using the Manley preamp and SIT 2 amp, objectively the LS50 has a flatter and more extended frequency response, overall less distortion, plus a less complex looking step/transient response. Though not measured here, lateral and vertical responses are also superior with the LS50 compared to old BBC-inspired speakers in general. I think this is a good example of modern speakers being objectively "better" due to improved design and materials.
Pricewise in 1980, a Spendor SA1 speaker was around US$230 each, for the less expensive walnut veneer (here's a Spendor price list from 1980). In inflation-adjusted 2019 currency, this would be around US$717 each or today's US$1400/pair. It seems that the Spendor SA1 when new would have been significantly more expensive compared to a modern US$850/pair KEF LS50 and have objectively lower performance.
Nothing against "vintage" gear of course, and like I said, everyone can have their own preference for sound. But I think it's reassuring that new products are able to provide better engineered performance at less cost. It would be sad for any technology-based hobby if in general it were not so!
Overall, I think that's a pretty good "haul" of data from a 4-hour afternoon visit to my friend's place! In that time, we did a bit of main speaker placement/settings optimization, created a DSP filter for him to try out, and had a little comparison of the disparate monitor speakers. Plus, the data also suggests that we should look more into the phase characteristic of the system. We even managed to sneak in a little bit of music listening as mentioned above including Louis Armstrong's Satchmo Plays King Oliver LP on his Linn turntable. I can tell that he did a great job with the turntable set-up and the analogue system maintained a nice low noise floor.
As you can imagine, this is a much different system than my own! Tube preamp, low-power exotic solid state amp, high-sensitivity large horn main speakers to match... Subjectively, this still sounds excellent and there's certainly something to be said about the impressive clarity, "palpability", and soundstage "presence" of reproduction from the huge horns even at low volume. Indeed, there are many ways to achieve sonic excellence!
As a hobbyist writing and thinking about consumer audio, it's fun to do this with friends! It gives me a chance to see what folks are up to, explore the rooms they're using, get a taste of their systems and music... Plus of course have some "intimate" access to the gear for more than just a listen compared to the likes of audio shows or the local audiophile showroom.
As I look around the various online reviews, I cannot help but feel that it's a shame not more reviewers are interested (or perhaps able) to complement their subjective impressions with measured data to reveal that which ears and brains lack resolution for (a good example would be polarity / "absolute phase"). These days, the software and equipment to do this are easily accessible without huge cost nor does it take lots of time to get the measurements done as shown here. The main investment is in learning how to do this stuff efficiently. I think it says something positive about a serious hardware reviewer if he were to invest in correlating subjective impressions with objective results. I definitely respect reviewers who have the breadth and depth of knowledge and experience to speak both objectively and subjectively about a product (and endeavor to do so myself). Alas, one can imagine why some boutique/exotic audio companies might not want their products tested objectively if they are not confident in the outcome.
Finally, I'd like to thank my audiophile friend and his wife for their hospitality. I got a taste of the-lady-of-the-house's homemade cookies and fruit cake - delicious! While I was visiting, she was also working on some festive baking and decorations and didn't even complain about the test tones and sweeps; now that's accommodating :-). Great to hear that her work was subsequently displayed in their community's holiday celebrations recently!
I'm sure next time we meet, there'll be more sitting back and enjoying the music ;-). But to be honest, I'm not sure my readership consisting largely of "hardware audiophile" enthusiasts here would find my subjective opinions about music or descriptions of sound quality alone to be that fun or useful.
(Hmmm... I'm already very curious about what kind of coloration we'd find with that Omega Maxhemp - whadda name - for next time!)
Jim Austin's article "Hi-Rez Audio Distinguished in Blind Testing" posted on the Stereophile site was interesting this week. If we are to just look at the title of that article, one would wonder if there is indeed something there to be excited about. But in fact, no, nothing all that exciting IMO.
If you're interested in adding data to a hi-res vs. CD-quality listening test, go take Mark Waldrep's (aka Dr. AIX) "The HD-Audio Challenge II". I think he's accepting submissions until early 2020, intends to publish on the data, and I've submitted my own results already. Maybe Jim Austin and the Stereophile writers might want to be of service and submit their listening results using their highest-end systems. I'm sure Mark would love to look for correlations with age, equipment costs, and hearing acuity in the data. If what is said is true, this should be a piece of cake for them given some of the claims around audibility and a nice example of "walking the talk" if they're honestly up for it.
As a side note, the comment by J.V. Serinus on that Stereophile post about the Rossini DAC upsampling CD and hi-res to 24/384, claiming he still hears "major differences" as if upsampling should make any significant difference is IMO a good example of "received wisdom" that mainstream writers hold yet of questionable validity. He apparently has expectations about what the upsampling technology is supposed to do and what he's perhaps supposed to hear. Gotta be careful about such suppositions given how the technology works!
Let's also consider this other comment Serinus made: (the public is) "not going to be swayed one way or the other by ceaseless debates about / condemnations of MQA on audio sites". The truth is that the public doesn't care about MQA at all, there was never anything interesting in it for them to begin with since hi-res was never really in demand. The debates and condemnations are meant for audiophiles who do care when it was clear that MQA was being pushed to audiophiles likely because of good will towards Bob Stuart and the Meridian heritage. Presumably the strategy was that audiophiles would further promote and perhaps be positive "influencers" for adoption of the scheme. It's a sign of integrity that advanced hobbyists and honest companies would do their part in examining claims and push back even if Serinus and much of the Mainstream Press are unable to understand and speak of objective, verifiable truths. IMO, the discussions have been fruitful and people (audiophiles) are swayed with significant repercussions for not just MQA but also how significant portions of the Press, certain "gurus" and companies are viewed. This is an important feedback mechanism that Mr. Serinus needs to respect as a matter of service to maintain a genuine and healthy hobby that's not just run by and for commercial interests.
In a related Stereophile article - "Slow Listening" - we again see the tired justifications for the extreme Golden Eared "subjectivists". The reader comments are telling however. While perhaps "more subjective" in mindset, the comment by tnargs is excellent and a good reminder that shades of grey do exist in this world and my "more objective" stance isn't all that different from what he's saying. In a world where polarities seem more striking especially in political debates, perhaps we in the audiophile microcosm can actually be on the leading edge of finding rational, centered, common ground. Interesting that the term "fidelity" was brought up in the article and then quickly tossed aside in the service of the supposed "stress relief" of 2nd order harmonic and the "BBC dip" as if these are all equivalent in importance or value. I suggest Mr. Austin might want to do a little more soul-searching on what fidelity means and whether this performance ideal holds a special place in this hobby. Perhaps "purely subjective, likely expensive, manufacturer-friendly euphonic audio" is all that ultimately matters to him and his magazine (as is apparently the case with TAS / Hi-Fi+ for awhile now IMO).
May I suggest pondering on the question of whether "hi-rez" has value without "high-fidelity" playback as a start?
If we look back at the decade of the 2010's as audiophiles, the rise of audio forums, no-nonsense discussions (including criticisms of MQA) and hearing from diverse voices beyond the traditional audiophile press have been highlights for me. Remember, Audiophilia is not a religion. Audiophiles need not be "audiophools". There are no "high priests" in this endeavor with a special, close relationship with ultimate audiophile Truth. There are no esoteric gnostic rituals needed to enjoy and experience hi-fi sound. As in other areas of life, faith is not bestowed because somebody said so, but in general, earned, whether we're talking about an Industry, the Press, or as individuals. Modern audio devices are electromechanical products engineered by humans and developed out of scientific principles, not the result of a metaphysical Creator nor complex evolutionary processes, and should not be evaluated any differently. Some devices sound bad, some great, but none are divine. Beyond objective results, we can still respect a person's subjective preferences, but those are on the level of opinions of which we can all form for ourselves and hopefully, insightfully, civilly express. Opinions are not necessarily facts. And measurements should also be replicated for confirmation when possible.
I believe this decade is ending as a friendlier place for rational audiophiles on the internet. That seems like a good thing. In the 2020's, let's continue to look for opportunities to realistically understand and build upon what we have today, maybe even rejuvenate the best from the past.
With that, I wish you and yours a very Merry Christmas and Happy New Year. I've got some fun stuff to do with the family and time to just enjoy the music, savor the food, ponder the season, and imbibe the atmosphere.
Let's chat again in January as we also enter the next decade...
BTW guys, I'll be in Seattle over the holidays for a few days... Any recommendations where an audiophile might want to spend a few hours either checking out hardware or maybe a highly-recommended music shop especially in the downtown area?