Sunday 7 July 2024

Seating variations, multi-seat correction & multichannel DRC. The audio "sweet spot".

A look at the rear of my room and the sofa seating - surround speakers, LP rack for a little bit of diffusion room treatment. For best practice, it's important to not sit too close to the back wall. I have 3' between the couch and the LP rack, and the rack is about 17" deep before that back wall. 

Before putting the UMIK-1 microphone away after using Audiolense XO as discussed last time, I thought it would be interesting to explore in greater detail what happens with frequency response and time-domain performance as we sit off the "sweet spot" where the measurements were collected and correction calculated for.

In the image above, I've put a meter stick on my listening couch to identify the seating positions 1 and 2-feet to the right and left of that sweet spot so I can take detailed measurements of what happens to the sound coming from the 5 main speakers at those positions with and without DSP turned on.

Saturday 29 June 2024

Multichannel Digital Room Correction with Audiolense XO. And "What's your budget?".

As you might recall from over the years, I strongly believe that one of the most important things one should try as an audiophile seeking high-fidelity - after having a decent sound room, and getting good equipment - is to consider the use of room correction. It could be as simple as frequency-domain EQ correction for larger bumps and dips (as discussed with the Behringer DEQ2496 hardware back in 2013-2014, device measurements here), or the much more sophisticated frequency and time-alignment of filters created by software like AudioVero's Acourate (and 2019 update) capable of much higher resolutions.

The power that one has to optimize and customize the sound runs well beyond most hardware upgrades other than wholesale speaker replacements and changing sound room! The change one can expect with room correction dialed in is astronomical compared to all the snake oil tweaks, cables, hi-res DAC/streamers, even amplifiers you might want to throw at your system.

These days, I've increasingly been converting multichannel content over to my Roon server, typically 5.1 SACDs and DVD-As but also Bluray rips, ideally lossless TrueHD with 7.1 channels. Unfortunately, Roon is currently unable to decode codecs like EAC3-JOC (lossy multichannel/Atmos) or TrueHD (lossless, based on the MLP codec) so the content typically gets transcoded to multichannel FLAC-compressed PCM which can handle up to 7.1.  

Although Acourate can be used for multichannel filter creation, the manual procedure here is unfortunately quite involved and more than most audiophiles would like to get their hands dirty with! Which is why today's post is going to be about multichannel digital room correction using Juice HiFi's Audiolense XO (€390, currently version 6.21). I see that there is the less expensive Audiolense Surround which I suspect could be enough for many users, and if all you need is 2-channel stereo, there's Audiolense 2.0.

Tuesday 18 June 2024

MEASUREMENTS: Nordost-like flat silver-plated copper speaker cables. And, comments of a "high-end" cable insider compared with an apologist?

Cables are fun to play with! They look different, there are all kinds of brands available, and for some audiophiles, there's a sense that the sound has been "changed" if not "improved" when trying products at different price points. All without lugging big and heavy speakers or amplifiers around which makes the upgrade easy especially if one believes that the change can be equivalent to such component swaps! Speaker cables in particular would be the most interesting because they carry complex musical signals of potentially high current and voltage for longer lengths. (Digital and power cables are least interesting for me for obvious reasons - here's my summary post of cable measurements over the years.)

I've already talked about a number of different speaker cables in the past; most recently here, here, and here. Notice that morphologically, all of them have been "roundish" cables so I thought it would be fun to try something flat and measure to demonstrate the LCR changes that this kind of design provides.

Looking around AliExpress, I found the cables above - China-made Nordost-like speaker cables - I bought the 2.5m pair with locking gold-plated banana plugs for less than US$100. There are similar products found on Amazon but you'll need to shop around for a good price.

I think the design of these are probably most similar to the Nordost Heimdall 2 cables which currently retail for about US$2,500, 2m pair.

Saturday 8 June 2024

The E1DA Cosmos Stack: ADCiso and 2 APUs. An example of bad multichannel - Neil Young's 'Harvest' on DVD-A (2002), fixed in new Atmos mix.

E1DA Cosmos ADCiso Grade A center.
Cosmos ADC Prototype I've been using over the years to the left.

Readers here probably are aware that over the last few years, I've been using the E1DA line of devices, the Cosmos ADC, APU, and Scaler typically paired with PC-based software like Room EQ Wizard for most of my measurements, especially for the highest fidelity products like DACs. As a hobbyist exploring objective performance, there's obviously no need to spend thousands of dollars on devices like the Audio Precision (here's a peek inside the APx555B top-of-the-line model, around US$30k). Not enough return on investment unless one is doing professional product design and testing.

As usual, over time things evolve around here and since I needed an extra ADC for work-related purposes, I bought one of the newer E1DA Cosmos ADCiso Grade A to replace the prototype that Ivan sent me back in 2021 which I will repurpose elsewhere.

This post is mainly an update and comparison, refer to the original article on the Cosmos ADC for more details.

Saturday 1 June 2024

"High-End" DAC Blind Listening Results - PART III: Subjective Descriptions

In this last part of the "High-End" DAC Blind Listening Survey write-up, (see Part I, Part II) let me document the more qualitative aspects of the responses I received from listeners. These come from the comments section where listeners described what they heard. You'll also get to see in context some of the descriptions of the hardware used in the evaluation.

Comments will be posted verbatim other than removing any identifying information and names unless the person specifically says it's OK. Not all comments are posted, only the ones with a fair amount of subjective experiential content or description of evaluation procedure. It's interesting knowing which city/country some folks are from so I'll leave that information if mentioned.

So as not to neglect those who said they heard no difference (yet I know many spent a good amount of time on the test), let's start with that group of respondents... I'll add some comments/responses along the way.

Saturday 25 May 2024

"High-End" DAC Blind Listening Results - PART II: Results & Analyses

I imagine that the banner graphic above must be so bizarre for some audiophiles! How is it even possible that the audio output from something cheap like the Apple USB-C headphone dongle could be mistaken for the way more expensive Linn digital streamer devices that cost orders of magnitude more?!

Well, of course we can! And if we are to honestly appreciate the difference in sound output between the very cheap and very expensive (we can buy a lot of other stuff, services, and experiences for US$20,000!), IMO, as audiophiles, we must open our minds to such comparisons. The hi-fi audiophile pursuit is not a cult; everything is up for empirical examination regardless of company, price tag, or which heroic personality is attached to said product.

Last week in Part I, I unveiled the identity and discussed those DAC/streamer devices. Let's proceed today with looking at the data from the recent 2024 "High-End" DAC Blind Listening Survey which collected listener impressions for 6 weeks; plenty of time I trust for those motivated to download, listen, and offer their subjective opinions.

As usual, let's go through the data broadly and then let's see if the results can provide some answers for specific questions around audibility, preferences, and listener subgroups. I'll group these questions and evaluations into a number of Sections.

Grab your favorite beverage, have a seat, this is a pretty long one... 🙂

Saturday 18 May 2024

"High-End" DAC Blind Listening Results - PART I: Devices Unveiled!


The time has come friends. Over the last 6 weeks, I've been collecting the data from the 2024 "High-End" DAC Blind Listening Survey. The procedure I think is already well described in that test invite post so I won't spend time here recapping that. Thanks for everyone who participated in the blind listening!

As with many blind listening tests, unless it's literally obvious, I know it's not easy to flip back and forth and it's very common after a few A/B/C switches to second-guess oneself! I certainly appreciate the time that participants spent downloading the >500MB file, getting it onto your listening devices, and the listening itself.

For this post, let's talk about the test, some rationale, and let me unveil the 3 DACs that were used.

Saturday 11 May 2024

NYC Explorations: Audio46, Stereo Exchange, and dwindling audiophile stores.

New York - after the rain.

Hey everyone, it's nice to be back home on the West Coast after the trip to NYC. May is a great time to visit so long as one catches some nice weather! At least it's not too hot yet. I'm sure if it were not for the COVID pandemic, I would have visited much sooner; the last time was back at the end of 2015.

Let's see, as we await the final results to come in for the "High-End DAC Blind Listening Survey" (closes on May 15, 2024), this week let's show a few pictures from New York, and see if I had any luck finding some good audio to listen to 🙂.

Saturday 4 May 2024

MUSINGS: On Hardware Audiophilia and Wine Tasting.

Across the years of audiophile discussions, we sometimes will see parallels drawn between the world of the oenophile (wine connoisseur) and hardware audiophile. While both pursuits involve a strong subjective component since the ultimate intent is enjoyment, there are also clearly differences when we take the time to compare them. I actually don't think many of the heated debates among audiophiles have meaningful analogues within the wine-tasting world.

Recently, in this thread on Steve Hoffman Forum about "snake oil", J-Flo made a nice comment on this; let's have a look at his post and I'll add my observations and thoughts with some opportunity to expand upon the ideas.

Saturday 20 April 2024

As We Hear It: Audiophile cable truths, claims, and reviewer age. Multichannel "madness"?

Hey everyone, this week let's have a look at a recent E-mail I received and think about the "classic" audiophile topic of contention over the decades - cables!

It has been awhile since I've talked about cables (I've published a number of cable measurements over the years, links collected here). It's not much fun talking about cables these days because after awhile I think most of us have tried enough cables and honestly just realized the truth that it really doesn't matter what the salespeople claim. There are better things to do like just sitting back and enjoying the music than obsessing over what essentially are minutiae with less potential effects* than hi-res audio recordings (which itself is usually questionable).

[* Unless of course the cable intentionally acts as a filter like some of the MIT cables - as per their patent.]

Here's an E-mail I received from reader JW Haus in March in response to a magazine article in Stereophile:

Saturday 13 April 2024

Detailed THD(+N) vs. Output Level Measurements of ESS ES9039Q2M. Balanced output quality from Hidizs AP80 PRO-X DAP. And Tekton's self-inflicted PR disaster.

Hey everyone, I wanted to post a follow-up of sorts to a couple of previous articles. First, the article "Hi-Res THD(+N) vs. Output Level Measurements (ESS "HyperStream" vs. AKM vs. TI/Burr-Brown). And a bonus R-2R!" was published back in the summer of 2022 showing an interesting sinusoidal pattern in the harmonic distortions with ESS DACs.

Since then, with the release of their newest ES9039 DACs which employ their latest "HyperStream IV" modulator, I thought it'd be cool to have another look...

Another follow-up is a look at the 2.5mm balanced output from the Hidizs AP80 PRO-X Music Player which was measured last year. At that time I didn't do the balanced output measurements so let's capture a few metrics and compare this with the single-ended 3.5mm output.

We can then end off with some audiophile social commentary from this week's drama.

Saturday 6 April 2024

2024 "High-End" DAC Blind Listening Survey!

*Surprise!* It's time for another listening survey.

I like doing these once awhile because it's an opportunity for audiophiles to actually listen for differences between devices, resolutions, or even things like filter settings for themselves as opposed to hanging on to the testimonies of others whether in text or expressed in videos. We can argue all day long about whether THD+N of -120dB is better than -85dB, or if a US$20,000 DAC sounds better than a US$500 one; what matters ultimately is in the listening.

[I agree with Taylor Christensen in his excellent article on "subjectivisms" that what we need more of these days is audibility data to address the category of "scientific subjectivism"; not just opinions or measurements.]

This time, I'll be using recordings of the AMPT Test Track from 3 different DACs for you to listen to. These were created based on my standard procedure of recording and processing described in the link. The only difference is that I'll be using the 24-bit version of the AMPT for this survey to maximize higher resolution dynamic range potential from the DACs.

As a blind survey, I will not tell you which DACs these are to minimize bias. What I can say for now is that these are not devices from Chinese brands although anything can be "Made in China" these days (ie. these are not Topping, SMSL, Sabaj, Shanling, Matrix, Gustard, etc.). Some of these devices can be considered "aspirational" DACs or streamers in that the MSRP of the device could be out of reach to many, even priced "ridiculously" high.

Perhaps this fact might encourage you to listen for yourself: the difference between the least expensive and most expensive device is >100 times!

Saturday 30 March 2024

Expensive Audio & Medical Quackery: Mark Levinson promoting Daniel Hertz "C Wave Technology". And the Maria amps. [Including company response.]

While perusing news updates the other day over Spring Break on my Google news feed, there was a suggestion to check out this YouTube video of an interview with Mark Levinson; apparently Levinson had something to say about "Let's Fix PCM Audio".

Clearly, this should be a fascinatingly insightful video, right? After all, we have one of the most well-known names in the high-end audio industry, and who doesn't want PCM "fixed" if indeed there is something to be done to improve the experience from decades worth of music!

Boy, was I disappointed by this "iconic" name in the audiophile world... Anyhow, grab a drink, have a seat. Let's talk about the many interconnections between technology, health, consumer psychology, and truth-in-advertising with this name and company.

Saturday 23 March 2024

EARLY LOOK (Part II): E1DA #9039S USB Balanced DAC dongle/headphone amp - DSD and performance under load. A few more words on the "need" for higher DAC fidelity!

Last week, I published Part I of the review/measurements on the upcoming E1DA #9039S USB dongle DAC/headphone amplifier. Already, we've seen that this ESS ES9039Q2M-based balanced DAC produces very clean, high-resolution sound.

As we continue, let's delve deeper into the performance of this little device. We'll have a look at some features like DSD performance and more importantly, let's examine the balanced amplifier output when subjected to headphone-like loads to see how well it performs.

Saturday 16 March 2024

EARLY LOOK (Part I): E1DA #9039S USB Balanced DAC/headphone amp - Super Hi-Res, Tiny Package! Also, let's tweak...

Hey everyone, it's time to have another look at a product from the engineering workshop of Ivan Khlyupin (IVX) at E1DA - the E1DA #9039S:

Notice balanced 2.5mm TRRS phono output.

As you can see, it's a prototype/preproduction (depending on whether the circuit could still change) unit with pen markings on the box for the number "9" to make sure the correct product was sent my way. 🙂

This is the latest iteration of E1DA's line of USB2.0 dongle DACs which includes the E1DA #9038D6K I had a look/listen to in late 2022. As you likely surmised, this update is based on the next generation of ESS Sabre DACs - the low-power, 2-channel, ES9039Q2M, using their sigma-delta Hyperstream IV modulator. The chip specifications list 130dB of dynamic range, -126dB THD and -120dB THD+N. We'll see in a little bit what Ivan has been able to "cook up" in his lab including some performance results. Back in 2022 with the #9038D6K DAC, he had already achieved -120dB THD+N (120dB SINAD) with single-ended output. How much better does it get!?*

As I sometimes do, due to time limitations, I'll split this write-up into 2 portions to present different roles/functions of the device. For today's Part I, let's just focus on the usual look-and-feel as well as using this device as a straight, unloaded balanced DAC. This will give us an idea of the performance capabilities of the ES9039Q2M in the hands of an experienced engineer. Next time we'll examine this device as a headphone amp.

The current anticipated price for this USB DAC/amp is presumably going to be less than US$150; I believe the exact number is still being crunched.

[* Asking how much better in terms of THD+N is of course a different question from "How much resolution does a person need for excellent high-fidelity reproduction?"!]