Saturday, 9 November 2019

RETRO-MEASURE: Klipsch Forté I speaker impedance. (And it looks like Qobuz responds to Amazon...)

Well guys, I'm still working on the Autoranger amplifier test system looking at standardization of the measurement technique and settings which is a pretty big job still, so this week I thought I'd show you some data I grabbed a few months back while working on the speaker impedance measurements series (Part 1, Part 2).

Every once awhile, I'll drag up an old device for a quick measure. Previously it was stuff like my old Sony SACD player, or the old laser disk player. This time, I went over to my dad's place to have a listen and measure his main speakers - the Klipsch Forté (original first version) made back in the 1980's until the early 90's I think.

Front and Rear of Klipsch Forté from the 1980's. Note the large 12" rear passive radiator.
I thought it was good to have a look at this device since there's been buzz lately about the latest model Forte III (Stereophile review, Darko review, Darko bought a pair). Also, a couple years back I ran into this Stereo Review article by Julian Hirsch on these speakers from 1986 as an example of what SR tests looked like back in the day:

Saturday, 2 November 2019

It's Alive! The Linear Audio Autoranger MK II...


And the kit is now alive just in time for Halloween the other night. :-)

For those still wondering what this is, you can check out Jan Didden's video of the Autoranger MK I from 2017 and his demo of how it's used:


Saturday, 26 October 2019

On Audiophile Forums. Disagreements on MQA. (And Redscape preview...)


I thought for this post it might be good to talk about audiophile forums.

A couple weeks back, some of you expressed frustration with the Audio Science Review Forum, the opinions of the host there, and general MQA disagreement. Over the years, like probably many of you, I've had my share of participating in forums, disagreements with views expressed and the bickering at various venues. All in good fun however and nobody needs to get too perturbed... It's only a hobby, right?

I've read posters say that MQA is "the gift that keeps giving" :-). No doubt it's a topic that has provided for much discussion around here and elsewhere!

However future audiophile historians ultimately judge this time in our hobby, I think MQA will have its place as a controversy that divided the community deeply. I don't think this is a bad thing in that it has provided many opportunities for us to discuss and perhaps be enlightened by what is true vs. false, shown a divide between mainstream press with close industry ties vs. independents, objective vs. subjective testing, faith in (specifically one) authority of digital audio vs. skepticism. And this has played out publicly probably in its most dramatic fashion on audiophile forums these years.

Saturday, 19 October 2019

Gone Building... Linear Audio Autoranger MK II.

Linear Audio Autoranger Mk II "quarter kit". Attenuator board (yellow-gold), Control/Display board (green-blue), SilentSwitcher power supply board, metal case, USB-A connector, and programmed microcontroller in the anti-static bag.
Hey guys, during the summer, I got the above kit from Jan Didden at Linear Audio. As you can see on the front, this is the Linear Audio "Autoranging Attenuator" - also known as the "Autoranger", standard 10kΩ version.

Saturday, 12 October 2019

2019 Update: Basic Acourate DSP Room Correction (using Dayton Audio EMM-6 mic, and other related bits...)


As I mentioned last time, I changed the tweeter in one of my speakers resulting in a significant adjustment to the frequency response in the 2-5kHz range. This means it's time to update my AudioVero ((acourate)) (current version 1.9.12, 286€) room correction filters for late 2019. Looking back, I haven't posted on this since 2016! My, how time flies.

Given that it has been awhile, picking up Acourate again for some measurements required that I dig out my old notes and review the previous procedures again. As such I figured that it was time to write an update for a reasonably "quick and dirty" measurement which basically took me an afternoon to perform with excellent results. If you've tried Acourate, you'll know that this program is very powerful but can take a bit of time to figure out the interface and get comfortable with the process.

Okay then, let's get going with a quick but detailed summary while it's fresh in my mind and provide some pointers the next time I might have to do this again maybe in a few years :-). We'll then end this post with a few other related subtopics that came out during the measurements...

Monday, 7 October 2019

Paradigm Signature S8 v.3 Tweeter Replacement. A word about importance of speakers (+ rooms). (And a link to a HDMI cable blind test.)

Paradigm Reference Signature S8 v.3 tweeters.
I mentioned in late August with my "Speaker Impedance - Part 2" post that I noticed a variance between the right and left speaker impedance from my Paradigm Signature S8 v.3 that I was going to track down.


While an ohm here and there might look innocuous on the impedance curves, sometimes this could be indicative of a significant imbalance between speakers. Since I'm a bit obsessive about these things, let's get down to the "nuts and bolts" of the speaker and have a closer listen and look at the frequency response in that frequency region...

Saturday, 28 September 2019

MUSINGS: "Democratization", "Doublethink", MQA, and the Audiophile. Becoming "Post Hi-Res Audio". And some issues with vinyl...

“Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them.” 
“Freedom is the freedom to say that two plus two make four. If that is granted, all else follows." 
“For, after all, how do we know that two and two make four? Or that the force of gravity works? Or that the past is unchangeable? If both the past and the external world exist only in the mind, and if the mind itself is controllable – what then?” 
"In the end the Party would announce that two and two made five, and you would have to believe it. It was inevitable that they should make that claim sooner or later: the logic of their position demanded it. Not merely the validity of experience, but the very existence of external reality was tacitly denied by their philosophy."
--- George Orwell, selections from 1984 (1949)
It's sad sometimes reading how some (many?) in the audiophile press present products to consumers. Apparently, they'll stop at nothing to push a product even to the point of destroying their own credibility. It was bad enough a few years ago in 2017 when Robert Harley called for a "revolution" and that MQA represented a "paradigm shift"; making a mockery of the idea of paradigm shifts. And now recently he's "doubling down" to bring disservice to the idea of "democratization", linking it with the likes of MQA, in the article "From The Editor: Hi-Res Democratization" (The Absolute Sound, online September 6, 2019). Specifically, he seems to believe that those who oppose MQA is somehow fighting against the democratization of high-resolution audio for audiophiles! Really?

Saturday, 21 September 2019

Upgrade to AMD Ryzen 9 3900X Workstation Computer. (And Amazon Music HD/UHD opens to lossless and "hi-res".)

Being post-RMAF 2019 with all that talk in the last week or two with "high end" audio stuff, I figure I'll switch gears a little and take a look at computer tech instead.

One of the least enjoyable things I do every few years is to update the machines I use for work and the various ones I have here at home. While I don't enjoy the basic IT stuff and all the software installations that typically come with new computer builds, it's a good way to get updated on the machines out there, practice reasonable parts selection, and appreciate the price of the technology. Back in 2017, I updated my workstation here at home to an AMD Ryzen 7 1700 CPU which still is a very impressive processor for general use. But time marches on and my office workstation is really itching for an upgrade which hasn't happened since around 2014 and feels even slower than my laptop.

The idea then is to transition the Ryzen 7 over to the office and let's build an even more powerful workstation here at home where I do most of my writings and media encoding. Furthermore, let's try out one of the newer generation M.2 SSD drives that promise even higher transfer speed...

So, the result of a bit of online shopping:


Parts:
AMD Ryzen 9 3900X 12-core CPU (MSRP US$500, current scarcity higher price)
MSI X570-A Pro motherboard  (~US$150)
EVGA Supernova 750 G3 80+ Gold 750W power supply  (~US$130)
Corsair LPX 32GB (2x16GB) 3200MHz DDR4 RAM (~US$160)
ADATA XPG SX8200 Pro 1TB M.2 Solid State Drive (~US$150)
Corsair Carbide 100R Silent mid-tower case (~US$70)

Saturday, 14 September 2019

MUSINGS: Rocky Mountain Audio Fest 2019 - Reflections...

Assorted RMAF 2019 items... Dr. AIX book, demo disks. Collectable MQA brochure and the beautiful 135-page Wilson Audio catalogue! :-) In retrospect, should have also grabbed a T-shirt.
Beyond memories and photos - many of which already shared on Day 1, 2, and 3, the picture above are a few items I've kept from RMAF 2019 now that I'm back home in Vancouver. Each room that one goes into, one can pick up all kinds of interesting pamphlets, specifications sheets, colorful brochures. Most of these I have discarded as these days almost everything can be readily found online and in updated form.

Tuesday, 10 September 2019

RMAF 2019 Day 3...


As it has been said, Day 3 of audio shows tend to be a quieter day. It was no exception this year at RMAF. The picture above is from the "Headspace" ballroom down one of the lines of booths where headphone-related vendors display products and demo for the visitors. This picture was taken around 10:30 in the morning shortly after opening at 10:00. While number ebbed and flowed through the day, it wasn't difficult to find plenty of headphones to try and devices to play with as I wandered in and out through the day.

Since I did indeed start my day in the "Headspace" exhibits, let's start there and listen to a few interesting products...

Sunday, 8 September 2019

RMAF 2019 Day 2...

Alright guys and gals, let's continue with the sights and sonic impressions from Day 2 of RMAF 2019!

Here's a picture of Colorado Ballroom C where the seminars are presented. Bob Hodas was presenting on room acoustics this afternoon and I suspect this is one of the best attended sessions:


I was able to catch most of the presentation. There were a few useful tidbits I suppose, and I imagine it will be up on YouTube for all to see at some point. Hope he would have been a bit more concrete with the equipment he uses and provided more basic discussion on what he's looking for from the measurements he does.

Saturday, 7 September 2019

RMAF 2019 Day 1...

I must say that Colorado has some really pretty skies and lovely interplay of clouds and rays of sunlight...
Well, Day 1 of RMAF 2019 is done. Time to take a few moments to think about and review some of what was heard and seen.

The show started I believe around 10:00AM. It'll be interesting to see how the attendance numbers turns out but when I arrived around 9:30 to register, the line-up was rather long already - a good sign I hope for the organizers and exhibitors.

Thursday, 5 September 2019

Greetings from Rocky Mountain Audio Fest (RMAF) 2019...


It has been awhile since I've been at an audio show! Until now I've never really bothered to leave the comforts of home to attend any of these events unless they showed up locally... And a few years ago, VAS 2015 and then VAS 2016 happened which allowed me to get a taste of what these shows had to offer.

Saturday, 31 August 2019

MEASUREMENTS: Speaker Impedance - Part 2; sealed, ported, and a few of my speakers...


A couple weeks back, I started discussing speaker impedance curves and how one as an audiophile hobbyist might want to measure these ourselves. There are thousands of speaker models out there and while some in the audiophile press do a good job with providing objective results (like Stereophile), sadly, most magazines do not publish the information, and most manufacturers do not openly provide detailed specifications either. What else then can one do but measure it ourselves?!

Today, let's continue to explore the speaker impedance measurement graphs and see what else they can tell us using some of the speakers I use at home regularly...

Saturday, 17 August 2019

MUSINGS / DEMO: Why "Bits Are Bits". Let's not add unnecessary fear, uncertainty, and doubt.


Something I have noticed over the years commenting on the audiophile hobby has been how incessant and persistent various themes tend to be. Just like the apparently never-ending arguments of "digital vs. analogue/vinyl", or "CD vs. hi-res", or "subjective vs. objective", there has been this mostly friendly banter between those who feel that essentially "bits are bits" vs. those who think there is significantly more to digital transmission than bit-accuracy.

Seeing recently this article "Why the 'Bits is Bits' Argument Utterly Misses the Point" from Upscale Audio published compelled me to write this post to explore the topic further with a review of measurements and some demo tracks for readers to listen to themselves. I don't know how long the Upscale article has been on the site since there's no date or author listed, and was only made aware of it through the Darko.Audio Facebook page (it seems Mr. Darko felt the article was accurate, really?).

While the article claims that some people have "missed the point", let us examine their points and see if perhaps it might be the author(s) that are a bit too aggressive in making these arguments. After all, it is 2019 with decades of development in digital technology that impact our lives in more sophisticated ways than just audio reproduction. It's hard to imagine there are huge lacunae in our knowledge of digital communications and digital-to-analogue conversion of audio frequencies.

Sunday, 11 August 2019

MEASUREMENTS: Speaker Impedance - Part 1; measurement box, dummy loads and single speakers...

As you know, speaker impedance is not a "flat" resistance across the audio spectrum as one would find with a resistor. Rather when we measure the speaker load, we see fluctuations affected by the voice coils and crossover networks inside that speaker "box".

Remember that the electrical signal that represents "sound" are alternating waveforms. Thus we are in the domain of AC analysis when talking about the electrical properties of speakers which are typically "seen" by amplifiers as low impedance and complex "reactive" loads that will unevenly affect current and voltage due to capacitance and inductance. (For a good review with some math on the concept of impedance, check out the series of videos here.) As you've probably seen over the years, an important speaker measurement that can help us understand performance and the demand from amplifiers is the impedance curve (and the derived electrical phase angle).

As a hobbyist, measuring speaker impedance with excellent resolution is not difficult these days. We are blessed with free/user-supported software like Room EQ Wizard (REW) that can get the job done quickly and accurately. What we do need to do is to rig up a "sense resistor" to an ADC measurement device for the software to do its "magic". Here's a little black box I put together recently to get it done:


Saturday, 3 August 2019

MEASUREMENTS: AudioQuest Dragonflies Reviewed! Dragonfly Cobalt, Red, and v1.2.

Audiophiles following the news cycle know by now that the new AudioQuest Dragonfly Cobalt is out. About 3 weeks back, I noticed out of the blue (no pun intended), almost all mainstream audiophile websites had a post or promotional "give away" for one of these! Clearly this made a significant splash in the collective audiophile psyche.

Over the years, I've reviewed and measured these little USB DAC devices going back to the Dragonfly v1.2 in 2014. More recently, I wrote a series on the Dragonfly Black in 2017 with a good chunk of that looking at MQA "rendering". Note that I don't have the Black v1.5 here for direct comparison and will instead refer to those older results and articles as appropriate.

Here then are the 3 Dragonflies (Dragonflys?) I have in for a listen and on the "test bench" for direct comparison. From left to right - v1.2 (released 2014), Red (2016, ~US$200), Cobalt (2019, ~US$300):


As usual, I will start with building up the objective results and then later in the post, I'll talk about subjective listening impressions and broader ideas. I know this sequence appears backwards compared to how audiophile reviews usually are structured. Most reviews typically start with background on companies, personal anecdotes, people involved in the product, rationale, etc. If one is fortunate, maybe a sidebar or graphs at the bottom of the review for objective results.

As a "more objective" audiophile, the typical sequence above is not how I would prefer to learn about a new product. There are often insights one can gain through disciplined objective evaluation one simply cannot get based on company literature or even just listening unless one were truly meticulous. Objective results apply to us all, while subjectivity is the domain of the individual. As such, technical adequacy and fidelity IMO are much more interesting and significant than a company's history, who the "guru" was behind it, or to be honest, what the reviewer "heard" or probably more often than admitted, thought they "heard"; I'd rather leave many of those items as sidebars.

Sunday, 28 July 2019

MEASUREMENTS: "Noisy" Switching Power Supplies vs. Lithium Battery Packs (12V battery with RME ADI-2 Pro FS & Topping D10 DAC results)

Perhaps we don't think about it much or give it enough credit. I believe one of the advances in the last few decades that has provided the foundation for technological progress we enjoy today is the lithium ion battery. Li batteries were commercially released in 1991 and since then, thanks to the energy density available, combined with increasingly efficient electronics, all kinds of things these days can run off battery power - cars being the poster-child of this advancement...

A few weeks ago, I showed the little Class-D amplifier system running off a battery. How about we try out my RME ADI-2 Pro FS on batteries:


What you see here is the device connected to the Talentcell 6000mAh 12V Li-Ion battery pack. Since the RME ADC has become my standard for measurements in the last year, I have wanted to make it "portable". Talentcell makes an even smaller 3000mAh 12V battery which would work fine. While a little larger in size and weight, the 6000mAh unit is still lightweight and will be able to power the ADC/DAC for >5 hours - enough for any recording and measurement I would want to do in a single sitting.

Tuesday, 23 July 2019

SUMMER MUSINGS 2: Multichannel and the audiophile. MCh streaming with a TV Box. And Thoughts on the Future...


Hope you're all having a great summer... I thought I should take the opportunity to respond to this comment from Steven on the blog post last time broadly and with more details:
Steven 8 July 2019 at 21:07 
What about surround sound? Some of us are into that stuff. ;>
It does change things slightly. USB and S/PDIF won't suffice for lossless 4.0/5.1/and beyond audio data. That leaves HDMI or analog, afaik.
Excellent points Steven.

Surround/multichannel playback is important and sadly rather neglected in the audiophile world. I saw recently that the TAS website posted this article on the "rebirth" of quadraphonic sound.

Hmmm, isn't this actually the "rebirth of the rebirth" of quadraphonic? As I recall, there was a rather significant thing among home theater enthusiasts and audiophiles called multichannel SACD and DVD-A around Y2K :-).

Saturday, 6 July 2019

SUMMER MUSINGS: "How Much Difference Does It Make?" - On Balance and Adequacy for audiophiles.


The other day, I was reading Jim Austin's "As We See It" post on Stereophile titled "How Does the Music Make You Feel?". A relatively sensible article putting forward his and the magazine's perspective around finding "balance" between the subjective and objective sides of the audiophile pursuit. I agree with the central thesis, ultimately it is a subjective decision how one wants to spend time engaged in this hobby based on the emotional effect of music (I hesitate a little to say "music" here because let's be honest, not all audiophiles are in it for the music - sometimes it's the "sound" that's being sought). Music is art and appreciation of art will always be subjective, perhaps even wildly idiosyncratically for each person. Nonetheless, it's not that simple is it if we "look at the forest instead of the trees"? Let's take a higher level perspective and consider the audiophile hobby as a whole, rather than the audiophile him/herself. Are there some principles we might want to keep in mind?

Remember that what I've called "hardware audiophiles" are actually the niche hobbyists Stereophile is speaking and advertising to. I don't think Stereophile is of much interest to the multitudes of "music lovers" who probably are quite happy already with decent bitrate MP3 streaming over cell phones. As discussed before, these two hobbies intertwine but IMO are not the same. In every Stereophile issue, while some pages are dedicated to albums, music reviews, or maybe interviews with artists, the contents mostly discuss hardware products used in reproduction of the music. Our emotional response to reproduced music is a combination of the artistry in the music and science of reproduction. The audio devices used have technical characteristics that are objective and can be measured. As an analogy, in the visual arts world, we might or might not subjectively like the Mona Lisa, but when we look at a reproduction (photograph or scan of it), we can certainly experience and measure the differences between high vs. low resolution copies, and we can comment on or measure other objective traits like color saturation, accuracy, brightness, contrast, etc. compared to the "real thing" under the lighting conditions at the Louvre.

In reading that article by Mr. Austin however, between the personal stories and opinions, I noticed that like in most editorials covering this topic over the years in magazines, it's side-stepping a very important dimension. Achieving "balance" is not just about the way it is done (subjective listening +/- objective measurements), but also about the depth of exploration from which we derive adequacy. In other words, it's not just about whether we subjectively look at a car/woman/man and be captivated by its/her/his beauty, or whether the thing/person is objectively faster/taller/shorter/skinnier, but rather, are these qualities "good enough" for our intentions?

Let's expand on this...

Saturday, 29 June 2019

LISTENING: Fully battery-powered wireless streamer & amplifier system (Yeeco - TI TPA3116D2, TalentCell 12V battery)


A few weeks ago, I read this review on an independent audiophile site about an inexpensive Nobsound Class D amplifier based on the TI TPA3116 chip. I was curious so I ordered an equivalent one off Amazon - the little Yeeco Bluetooth-capable amplifier shown above with box contents including the 12V power supply for <$US32 (for an even cheaper package, here's one without the switching power supply, <US$25).

As you can see, the reviewer linked above gave the product some positive comments on the sound. I was curious to listen and since we know that Class D amps like these are very efficient, how about we run the playback system - music streamer to amp to speakers - completely wirelessly and battery powered for a listen also?

Saturday, 22 June 2019

MUSINGS and LISTENING: On Absolute Polarity / Phase... (And on the joy of the modern audiophile.)

Hey guys and gals, I thought for this post we'll spend a bit more time on the topic of "absolute polarity". As you can see from the post last week in the comments, our man in Japan Yamamoto2002 posted a link to his page where he has an interesting test signal for all to listen to.

If we look at the test signal he used, it's an asymmetrical waveform where half of it appears to be a standard sine wave, the other half has been "flattened" off which results in numerous harmonics if we are to display it on an FFT. One of the files is simply the inverted version of the other to test whether this polarity change is audible. Notice that the waveform is bandwidth limited, and there is no "ringing" after going through a digital filter.

Saturday, 15 June 2019

MEASUREMENTS: Topping D10 DAC. (And a few words on "absolute polarity / phase".)

Hey guys, getting busy around here as I'm preparing for summer holidays coming up in a couple of weeks :-).

I did want to post a "quick" report however on the Topping D10 DAC (<US$90) I got last week... It's for an upcoming project of sorts which I'll post on over the months ahead. What I wanted was a DAC that could be powered off USB, reliable with Window and Linux compatibility, that's reasonably portable, and of course of high signal accuracy.

Notice the DAC manual shows some AP measurement graphs... I guess Topping believes in showing objective accuracy :-). Nice.

Saturday, 8 June 2019

GUEST POST: Why We Should Use Software Volume Control / Management by Bennet Ng. (Plus discussions on resampling options, true peaks, etc...)


I received an invitation from Archimago to write something about volume control. While I am of the opinion that digital and analog volume controls can coexist to achieve an ideal gain stage, this article is mainly about PCM digital volume control.

The basic conclusion we can say regarding digital volume control is that as long as the playback device has higher bit-depth than the file source, it is possible to losslessly reduce the volume of a file until the playback device's bit-depth limit is reached. For example, with an ideal 24-bit device, it is possible to playback a 16-bit file 48dB lower without losing quality, because one bit has about 6dB of dynamic range (the exact formula of bitdepth and dynamic range is 6.02*n-bits + 1.76).

Saturday, 1 June 2019

POLL RESULTS: Music streaming service adoption among audiophiles in 2019...

Click on image to zoom.
Yeah, I know. Music streaming as a subscription model is the latest "revolution" for music lovers. This is why I decided to put up the recent poll in mid-March while we were concurrently also running the blind test as reported on in the last few weeks. Above, you see the overall results based on the visitors to this blog.

Remember that for the poll, I allowed voters to select up to 3 options. As a result, even though there were 616 respondents, a total of 809 selections were made. This means that up to ~30% of people selected more than 1 option and these are represented in the percentages above.

Saturday, 25 May 2019

BLIND TEST Results Part 4: "Do digital audio players sound different playing 16/44.1 music?" - Subjective Comments. Final thoughts on blind testing and critiques.


As we close off discussions and posts around the Internet Blind Test of devices playing 16/44.1 music, I want to publish some of the subjective comments from respondents who undertook this test... Impressions in the respondents' own words about the test when they submitted their results to me.

Remember that these are subjective. Human perception, especially when differences are at the margins of our perception are of course tough to describe. And when we compound that with the limited utility of words to describe ephemeral experiences (even with codifying the terminology as was attempted years back), it's no surprise that meaning can often only be conveyed as impressions. It's great to see the respondents trying their best and in many instances, I certainly appreciate the impressive use of language to express the experiences. Let's have some fun with these!

Saturday, 18 May 2019

BLIND TEST Results Part 3: "Do digital audio players sound different playing 16/44.1 music?" - Listener Results.


Thanks for the patience everyone. We are now into Part 3 of the report on the Internet Blind Test on the audibility of 16/44.1 digital playback using various devices. In Part 1 we talked about the test procedure itself and unblinded the devices (ASRock Z77 Extreme4 motherboard, Apple iPhone 6, Oppo UDP-205 as ethernet DAC, and Sony SCD-CE775 playing a burned CD-R).

Last week in Part 2, we reviewed the objective measurements of the 4 devices. I hope the readership recognizes the importance of doing this to set the context of what we're looking at this time as we dive into the results from the blind test respondents. As with many things in life, it is only with having facts at our disposal first, then we can make comparisons and develop ideas based on this foundation of knowledge.

Saturday, 11 May 2019

BLIND TEST Results Part 2: "Do digital audio players sound different playing 16/44.1 music?" - Relative objective performance. [And a few words about "Legends"...]


Last week, I revealed the four CD-resolution / 16/44.1 playback devices I used for this blind test. (By the way, if you want to have a listen to the original 16/44.1 track excerpts used, I added a link as an addendum to the post last week.)

While I'm still doing some counting, calculations, and writing the summary of the data, I think it's best this week to start by having a better look at those devices and seeing what objective results tell us about them so we can hypothesize what we might find when we examine the blind test results.

While it may be controversial to some in the audiophile world, I think we should keep our minds open to the idea that science and technology for digital audio playback has already surpassed the human auditory system. As discussed years ago, the human perceptual and cognitive systems do not have infinite resolution. I'm of course not discounting that the ears and mind have excellent abilities when it comes to appreciating miniscule differences, yet I think we have to remain humble; even if we believe we have "golden ears". Also, even if we don't believe measurements capture everything, it's not unreasonable to accept that the vast majority of what is heard can already be quantified in terms of fidelity to the source. This is why I think we need to explore the objective performance first... Then we can see if the subjective preferences from the respondents line up with expectations. I think for many of the well-respected audio engineers that design our hi-fi gear, this sequence makes sense. Ensure that the measurements are decent first, then verify and tweak with subjective listening.

Over the years, I've measured most of these devices in the blind test separately with different ADCs. For this post, let's run each one through the RME ADI-2 Pro FS and compare objectively using the exact same "measuring stick". For completeness, here's what the measurement chains look like with each player/DAC:

Saturday, 4 May 2019

BLIND TEST Results Part 1: "Do digital audio players sound different playing 16/44.1 music?" - Devices Unblinded! (Plus unusual exuberance & bias in the media?)


Thanks everyone for taking the time and efforts in performing the blind test which we started back in late January!

I officially closed off my survey from submissions May 1st (I promised April 30th, but gave a few hours more for stragglers from different time zones). I trust the 3 months provided plenty of time for everyone who wanted to perform the test to do so. I'll leave the blind test samples available for download for now and will take the files down in the near future.

You can read about the reason I ran this blind test in the previous post, but in a nutshell it's because of this poll result which I think reflects general audiophile perceptions on the question:

Saturday, 27 April 2019

MEASUREMENTS: Experiments in audio component grounding - using a bus bar & HumX. And on the last The Cranberries album, on audio quality legacy...


You may remember a number of years ago, I talked about reducing interference I was experiencing with my Emotiva XSP-1 pre-amp. The issue had to do with the audio system picking up interference and noise through the pre-amp's "Home Theater Bypass" unbalanced RCA input when connected to my AV receiver. This "HT Bypass" mode is used as a conduit for the front channels and subwoofer out when the AV receiver is in use, typically when I watch movies with multichannel sound.

While this was a bit of a hassle for me, sometimes out of these hurdles and limitations, one is provided with opportunities to explore things like the 8kHz USB PHY packet noise which seeped into my system from the TEAC UD-501 DAC (not an issues these days with my Oppo UDP-205). Playing with things like the Corning Optical USB 3 extender allowed me to lower the noise level. Furthermore, I was also able to show that different USB hubs affected the severity of that 8kHz noise. Remember that much of this investigation was prompted in those days when devices like the AudioQuest USB Jitterbug and the silly single-port-hub known as the UpTone Audio USB Regen were being hyped up by certain websites and forums. To this day, I have not seen any evidence that this stuff improved things like noise level and jitter with reasonable asynchronous USB DACs.

Saturday, 20 April 2019

A Look (and Listen) to some audio gear in Taiwan and Singapore...

Image result for window shopping

Hey everyone, as discussed recently, I had an opportunity to visit Asia over the Spring Break. Since it is "audio show season" with AXPONA in Chicago last week and Munich High End coming up in May, perhaps it's a good time to post up some images and descriptions of what I found in Asia this time.

While it was a family vacation, I found time to do a little bit of "window shopping" myself and check out the audio gear and stores overseas.

Thursday, 11 April 2019

COMPARISON: Roon DSP speed - Intel i5-6500 vs. Intel i7-7700K... (and the value of Intel Speed Shift!)


As mentioned, a little while back when I wrote about Roon, I was about to receive a "drop in" Intel i7-7700K CPU for my Server machine which runs Roon Core. I was able to find the i7-7700K used for a decent price and I didn't feel like dismantling the machine and upgrading the Z170 motherboard since the newest CPUs now need a Z3XX series board. Furthermore, for me, one of the least interesting "jobs" one has to manage as a technophile is reinstalling the operating system and software again... I try my best to avoid this mundane task :-(.

Note that if I were to rebuild my Server these days, I'd probably consider something like the very affordable Core i5-9600K with 6 cores. In fact, for most applications, this CPU will beat out the i7-7700K which I suspect would apply when using Roon for DSP as well.

Saturday, 6 April 2019

MEASUREMENTS: Roon 1.6 Upsampling Digital Filter Options & A Discussion on "Signal Path" Quality...


As discussed last month, I've started using Roon as my main music player for the sound room recently. Back in the days of Roon 1.2, many users performed upsampling using HQPlayer. While HQPlayer integration is still available (go to Settings --> Setup to access the installation option), since version 1.3, Roon has incorporated its own DSP samplerate conversion which I suspect would be completely adequate for the majority of users.

I was curious about the upsampling digital filter options available in Roon. If you look at the "Sample Rate Conversion" control panel, we see the four main "Sample Rate Conversion Filter" settings:


On the left panel, notice that Roon allows you to select the different DSP options and add various filters to the "chain" (left lower panel). "Headroom Management" is always available if needed which basically means you can set the amount of attenuation you want to use to prevent clipping while doing the DSP processes. Default setting is a very reasonable -3dB.

Tuesday, 2 April 2019

MUSINGS: Of Jokers and Clowns... (On Soundstage and Perspective)

More info here.
As I sit here watching the early light in the tropics enjoying a cup of Java, I had a look again at John Atkinson's editorial "Clowns to the left of me, jokers to the right...". I believe this April 2019 issue is the last one where he is the Editor-in-Chief of Stereophile. The article examines a recent event which again brings up one of the age-old contentious issues we run into with the audiophile pursuit (perhaps the most contentious issue ever) - the subjective experience of listening/enjoying music and the use of objective and controlled methods to help us understand how well our audio systems function.

"Sunrise Sentosa" - March 2019, Singapore
Over the years, I've written on the unnecessary "war" between "objectivism vs. subjectivism" when I've thought it worth addressing articles written by some members of the press and at times the strange fear of scientific methodology in high-fidelity. We've talked about the basics of what subjectivity and objectivity mean, and further elaborated on it. In summary, "pure subjectivism" and "pure objectivism" are both extreme positions to take. The problem I find is that for decades in the audiophile press, subjectivism has been posited as somehow more important if not the only worthy position to take to the point where the vast majority of hardware reviews available these days including online sources have lost the objective component. In the process, most reviews have also lost the power to elucidate truth among the subtleties of sonic differences. Without objectivity, sound quality cannot be adjudicated based on the ideal principle of high fidelity.

Friday, 15 March 2019

POLL: Do you subscribe to a music streaming service? And a Wilson Sasha DAW, dCS, Audio Research listening session @ The Sound Room, Vancouver.


Alright guys, first off, I'm trying out a quick poll here since I was interested in how many of you are currently streaming music off a subscription site... No doubt we are seeing the shift towards the streaming, subscription model for music delivery and consumption.

It's interesting to see this article recently about the music industry's revenue growth in these last few years on account of streaming. Considering the decades of decline, I'm sure the music industry is interested in promoting any system that nets a profit. We will need to see however whether the rate of adoption in streaming wanes in the years ahead as warned by Forbes recently.

Saturday, 9 March 2019

MEASUREMENTS: A look at the audio "ultra high-end" - ultrasonics! (And changes at Stereophile announced.)


In this blog installment, let's look at the "ultra high-end" of sound. Of course, I'm not talking about the audiophile "high-end" marketing term which is meaningless (beyond just another phrase for "expensive"). Rather, let's look at the frequency high-end, especially all the stuff our DACs can produce in the ultrasonic range!

If you've ever wondered, ultrasound devices used in medical imaging typically function at around 2MHz on the low end up to about 15MHz. However, the term "ultrasound" simply refers to wave
compression and rarefaction outside of the hearing range which by convention are those above 20kHz or so.

While the presence of ultrasonic content coming out of our DACs is not a surprise, what might be unclear or debatable is whether there is much of it and whether this then affects the "sound" of one's system. Rather than get bogged down in opinions, let's first have a look at what's in the ultrasonic frequencies coming out of DACs... Starting from facts, we can then perhaps come up with opinions.

Saturday, 2 March 2019

MUSINGS: Let's talk about Roon (1.6) and DSP speed... (And an example of a poor quality "hi-res" classical recording.)


I mentioned a few weeks back in a comment that these days I've been using Roon for my music library and playback. A few years ago, I tried out Roon 1.2 and while good, it just wasn't quite compelling yet at that time for my needs. For years I've been using Logitech Media Server (LMS) given that most of my devices had been Squeezebox-based until recently. It certainly serves the purpose well to this day and in fact, I still run it on my server. I'll discuss why later...

I trust that you've already read or seen videos of Roon in operation so there's no need to cover the program's basics. In fact, I think I covered quite a bit of ground already back in early 2017 with the demonstration of Roon 1.2 on an Intel NUC and then subsequently talking about the use of Roon Bridge with the Raspberry Pi 3.

Since that time, with the newer versions, the program has, as expected, gotten better with even more features, more powerful user interface, etc... I appreciate the better support with display of track names and various settings with the older VFD Squeezeboxes. DSP has been added as of version 1.3 with support for room correction, upsampling options for PCM and conversion to DSD for DACs supporting the feature. We might look at measurements of these options in future blog posts. Of course, there's now also the ability to perform the first (and IMO only meaningful) MQA "unfold" in software as of version 1.5; not that I'm a fan of MQA of course.

For today's post, I'll highlight a few of the key benefits, discuss CPU and DSP speed, ending with a few suggestions I would love to see in future versions...

Saturday, 23 February 2019

MUSINGS / MEASUREMENTS: On why 24/96 sampling of the Blind Test of 16/44.1 devices is good enough. [On idealized filtering tests and "real life" music playback.]



As promised, I want to address a comment raised about the idea that the 24/96 recording using the RME ADI-2 Pro FS ADC was somehow inadequate for the 16/44.1 samples in the "Do digital audio players sound different?" blind test; that the 24/96 captures are somehow missing significant amounts of the output from the devices.

For reference, I've included the original comment here from Miska:
"It [the samples] just barely catches the first image band between 22.05 - 44.1 kHz and a little bit of next between 44.1 kHz and 48 kHz. One of the devices is clean though. The ADC anti-alias filter fixes rest by improving the reconstruction by removing further image frequencies. Strongest image for most current DACs is around 352.8 kHz.

Of course playback system then defines how much overlay of these come back again at different frequencies from the DAC, since it is now running at different rate family than the original source.

This doesn't really replicate real device playback performance, but at least it captures some apparent differences. So it gives kind of hint or shadow of how the device actually did."
Although the blind test is ongoing, I figure it's still good to talk about this while not revealing the devices used of course.

Sunday, 17 February 2019

MEASUREMENTS: A Look At HQPlayer 3.25; Filtering, Dithering and DSD Conversion.


Over the years, no doubt many computer audio users have heard or perhaps tried using HQPlayer Desktop from Signalyst for music playback. While there is a GUI for playback as well as a sophisticated network transport architecture, it's the upsampling and PCM-to-DSD features that are the program's claim to fame. There has been a good amount of talk about the sound quality of the upsampling algorithms and some swear by the sonic differences the program makes.

While admittedly I don't follow HQPlayer chatter closely, I don't recall reading about specific settings and what they do other than opinions about the sound quality. In this way, HQPlayer has been a bit of a mystery and I know some folks have had difficulty getting it running over the years. It has certainly been on my list of items to look into. In fact, back in early 2017 when I wrote about Roon 1.2, I mentioned installing HQPlayer but never got around to actually writing about it.

Well, after all these years, and now with the requisite pieces of hardware at my disposal for a more thorough evaluation (reasonably fast CPU/GPU system, ADC capable of >192kHz, DAC capable of DSD512), it's time to have a peek "under the hood" at what it does...

Saturday, 9 February 2019

MUSINGS: Computer audio mythos? A comment on The Linear Solution's DS-1 Network Streamer.

Interesting... But in physical reality impossible of course! Perhaps like many audiophile opinions? [Info on art here...]
"Your desires and true beliefs have a way of playing blind man's bluff. You must corner the inner facts." 
--- David Seabury (1885-1960)
A few weeks ago, I read this "Quick Take" review of The Linear Solution DS-1 Network Streamer device published on Computer Audiophile (now Audiophile Style) by austinpop. Wow... I was impressed by how many computer audiophile "beliefs" were strung together all in one article! A good place to start and think about the "evolution" of computer audiophilia in 2019 perhaps.

Sunday, 3 February 2019

MUSINGS: Why bother with 24-bit DACs? (With thoughts on dithering, digital volume control, normalization, streaming and LUFS.)


I've heard over the years some people wondering whether there really is a point to 24-bit DACs. After all, there is little if any evidence that "hi-res" 24-bit music actually sounds any better - in fact, you might recall that way back in 2014, here on the blog we ran a blind test and the results did not show significant audible benefit among respondents. More recently last year, even with Dr. AIX's "HD-Audio Challenge", very few people were able to experience benefits to "hi-res" audio (no surprise of course!).

Saturday, 26 January 2019

INTERNET BLIND TEST: Do digital audio players sound different? (Playing 16/44.1 music.)


The other day, I was surfing the usual audiophile haunting grounds and came across this poll question on the Steve Hoffman Hardware Forum started a year ago. It reads: "Do You (Think) That Different CD Players Have Their Own Sonic Signature?"

Here are the results when I looked recently. I know it was closed last year, but it looks like it might be re-opened and still running into April if you want to cast a vote:


I thought it's worth spending some time to discuss this very simple question which of course is both understandable and asked frequently among newbies and longtime audiophiles alike. It's an important, and "core" question which can still be highly contentious after all these years! As suggested by the "blind test" title, by the end of this post, I will give you dear readers an opportunity to "cast your vote" and tell me what you think with a poll of our own using test samples to try (if you dare)!

 Let's make this our winter/spring research project...

Saturday, 19 January 2019

MEASUREMENTS: Oppo UDP-205 DSD Playback (DSD64-DSD512), and PCM 768kHz. Plus CES2019 coverage thoughts...


Alright guys and gals, it has been months since I completed the set of measurements of the Oppo UDP-205 last year (here, here, and here).

In early December, David M wondered how the Oppo performed as a DSD player as I had neglected to measure that.

Over the years, I have measured DSD output performance but remember that this is a little bit of a pain :-). To obtain some results for comparison with PCM in RightMark, what I typically do is take the test signals (originating in 24-bit PCM), convert to DSD using software like Weiss Saracon, and then play back the DSD file through the DAC into the ADC which of course takes that analogue output resampled back into PCM for analysis. Doing this understandably adds other variables to the measurement system which should still be minuscule. Over the years, I have looked at things like PCM-to-DSD converters (here and here) to demonstrate that the conversion programs do have an effect as one would expect with different resampling and modulation algorithms.

Saturday, 12 January 2019

GUEST: Future Proofed (and didn't know it) - Adding Streaming to My Existing Hi-Fi.

Every once awhile, it's great to have a guest writer put up their thoughts on the Musings. I've always lived by the principle of "it really isn't what you got that matters, but how you make the best of it". I think Allan's post here is a nice example of that. These days, we have all kinds of products and technologies easily available at good prices, but when mixed with streaming services, sometimes one needs to do a bit of digging to get everything to work right the way one desires. One could spend countless dollars on things that might or might not really be of value. How we use what we have can take all kinds of forms and ultimately is a reflection of us taking control to satisfy our needs while reflecting understanding of how the products and services work... This Guest Post is a nice reminder of that!

Take it away, Allan...

GUEST POST
by Allan Folz


Introduction

Last spring on this humble blog I wrote a guest post reviewing the Sony HAP-S1. At the time I had a number of complaints with regard to the feature set. Indeed, I wasn't entirely sure I was going to keep it for the long-term. My biggest problem with the HAP-S1 was that I could not use it with any of my preferred Internet streaming services. The HAP-S1 has a pair of analog inputs and I bought it thinking I could use those with the headphone jack on my phone and laptop to be able to play back music streamed from the Internet. Also, while I knew when I purchased it that it didn't support Bluetooth, I had planned to get a Bluetooth to analog-out receiver that I could connect to its analog inputs. Unfortunately, after I received the unit I discovered there is a limitation in that the analog inputs can only be used to drive the HAP-S1's internal amplifier. Since I was using the line-out of the HAP-S1 to drive a pair of self-powered monitors, there was no way to get the signal from the analog inputs to the line-out. Instead, I'd have to move the monitor's input wires from the HAP-S1 to the phone or laptop each time I wanted to switch sources, which was a non-starter. (Or purchase a pre-amp, which was far more expense and space than I was interested in undertaking.)

Saturday, 5 January 2019

A Look at the Oculus Rift Touch VR System! (And the Oppo UDP-20X gets a firmware upgrade for HDR10+.)

Happy 2019 everyone!!!

It looks like Archimago was a nice boy in 2018 :-). Look what Santa brought him under the Christmas tree:


The Oculus Rift + Touch VR Bundle runs very well on that Intel i7 / nVidia GTX 1080 computer I have in my sound room.

As I mentioned last time at the end of 2018, I don't use the "man cave" just for 2-channel music listening (I think instead of calling it a "sound room", I should rename it my "media technology room"). Today, I'll just share a few thoughts on this device. While this isn't the usual stuff I talk about around here, I think it's good to look outside the audio hobby regularly and consider all the things the modern media technology hobbyist can do that vie for one's attention and time! VR being one that's still IMO very much in its infancy...