New 28-bit DAC coming out.

[Scytales]

Hello All! This is my first post to ASR.

I’ve owned the imersiv D-1 DAC for about three months. I found this forum only recently when searching for impressions of the D-1. I was intrigued by the comment by aagstn, “The D1 review posted states the DAC has ‘unshakable sense of completely unobstructed transparency.’ So does the SMSL SU-1 for $70. If this $12000 DAC is truly transparent as is claimed, how can it sound different from a $70 DAC that is also tested and proven to be transparent?” So, I purchased the SMSL SU-1 from Amazon for $84.95 plus tax to compare with the D-1. I believe I have an open mind, and I’m always interested in learning.

For my test, I chose the Benchmark HPA4 because it was measured as essentially transparent by Amir. I used Dan Clark Audio Stealth headphones because I have them and they were recommended by Amir. I wanted to carefully listen for any differences in these DACs and chose closed-backed headphones rather than loudspeakers to isolate the sound from my room as best I could. I used a miniDSP EARS headphone measurement rig and REW to match the sound pressure of a 300 Hz sine wave tone as closely as I could between the DACs. The D-1 has only balanced outputs and the SU-1 has only unbalanced outputs. I used the HPA4 to switch between the outputs. I know the manufacturer recommends going straight from the D-1 to a power amp, but I couldn’t figure out how to quickly compare the DACs without using a preamp between them. Roon was used to switch between the USB inputs of the DACs. I adjusted the volume on the HPA4 as I played different music tracks via Roon on my PC and kept a consistent 10 dB difference between them, as calibrated with EARS, for every music track I played. I was able to switch between the DACs in about 7 seconds. I did not conduct a blind test.

This test was harder than I thought it would be. At times I thought I heard differences in more complex music, but I believe I was inadvertently focusing on different aspects of the performance. I went back-and-forth multiple times and played segments less than 2 minutes long to try and better recall what I heard while still listening to a variety of sounds. The comparison was must easier with recordings of single instruments, such as solo acoustic guitar and solo piano in reverberant recording spaces where I could better focus.

I essence, I concluded I heard no difference between the D-1 and the SU-1. Though I did not conduct a blind test, at times I lost track of which DAC was playing and had to check Roon. I really like the imersiv D-1, and I don’t regret purchasing it. I think the D-1 is a very high performing DAC. The SU-1 isn’t much to look at, but I am very impressed by its performance. I’m posting my perceptions not to cause a controversy. I like that I learned how transparent and high performing an inexpensive audio component can be. This experience has taught me to try to better understand why I hear what I hear when auditioning audio components and has motivated me to further investigate the science behind audio. I hope others who may be curious about why a component sounds the way it does will also be curious and investigate why, even with components they already own.

Welcome, Mano74.

This humble and honest account of a well-conducted, albeit somewhat limited, and very well-documented experiment is highly interesting.

Your intellectual honesty deserves praise.

 

[RandomEar]

Hello All! This is my first post to ASR.

I’ve owned the imersiv D-1 DAC for about three months. I found this forum only recently when searching for impressions of the D-1. I was intrigued by the comment by aagstn, “The D1 review posted states the DAC has ‘unshakable sense of completely unobstructed transparency.’ So does the SMSL SU-1 for $70. If this $12000 DAC is truly transparent as is claimed, how can it sound different from a $70 DAC that is also tested and proven to be transparent?” So, I purchased the SMSL SU-1 from Amazon for $84.95 plus tax to compare with the D-1. I believe I have an open mind, and I’m always interested in learning.

For my test, I chose the Benchmark HPA4 because it was measured as essentially transparent by Amir. I used Dan Clark Audio Stealth headphones because I have them and they were recommended by Amir. I wanted to carefully listen for any differences in these DACs and chose closed-backed headphones rather than loudspeakers to isolate the sound from my room as best I could. I used a miniDSP EARS headphone measurement rig and REW to match the sound pressure of a 300 Hz sine wave tone as closely as I could between the DACs.

You did the right thing with level-matching! In my experience it is much simpler and way more reliable to reach the required precision of better than 0.2 dB (ideally below 0.1 dB) with a multimeter in mV mode. Due to the DACs using different connections (balanced vs unbalanced), the voltage would have to be measured at the headphone output of the HPA4, which could be a bit tricky. Assuming that the headphone out and line out of the Benchmark are both controlled by the same volume pot, it could be OK to measure the line outs instead.

The D-1 has only balanced outputs and the SU-1 has only unbalanced outputs. I used the HPA4 to switch between the outputs. I know the manufacturer recommends going straight from the D-1 to a power amp, but I couldn’t figure out how to quickly compare the DACs without using a preamp between them. Roon was used to switch between the USB inputs of the DACs. I adjusted the volume on the HPA4 as I played different music tracks via Roon on my PC and kept a consistent 10 dB difference between them, as calibrated with EARS, for every music track I played. I was able to switch between the DACs in about 7 seconds. I did not conduct a blind test.

I'm not quite sure I understand the 10 dB difference, but I assume that is due to the balanced/unbalanced difference, right? So you needed to change the volume when switching DACs? If so, that is pretty cumbersome and limits your minimum switching time. 7 s would be pretty fast under those circumstances. In a perfect world, there would be some way to get that time to below 1 s, but I understand that this can be hard to do in a typical home HiFi setup.

This test was harder than I thought it would be. At times I thought I heard differences in more complex music, but I believe I was inadvertently focusing on different aspects of the performance. I went back-and-forth multiple times and played segments less than 2 minutes long to try and better recall what I heard while still listening to a variety of sounds. The comparison was must easier with recordings of single instruments, such as solo acoustic guitar and solo piano in reverberant recording spaces where I could better focus.

Yes, listening comparisons at that level (where there is no difference or it is just bordering audibility) are extremely challenging. I am surprised each time people come here to claim that they "heard a night an day difference" between so and so while I - having done a couple of blind ABX tests - rarely had that impression with any subtle defect. That being said, due to our limited echoic memory, it is more revealing to play very short (< 10 s) but challenging sequences in quick A/B succession if differences are small. For larger differences like a broad dip in the bass or treble region (which would not be expected in a comparison of good DACs), longer music sequences can help distinguish the general "feel" of the songs in my limited experience. Though for most other characteristics, short + quick switches wins for me. But I understand that this is difficult and no fun when the switching itself takes 7 s.

Such a test is less of a music listening and more of a focused hearing exercise for me. Therefore, it's not pleasant like listening to a good track and more like actual work. I think most audiophiles don't want to put in the work or don't know that it is required and hope they will get the same result by casually listening to a few tracks and going "yep, heard that" - which absolutely does not work. You put in the work, which is commendable!

I essence, I concluded I heard no difference between the D-1 and the SU-1. Though I did not conduct a blind test, at times I lost track of which DAC was playing and had to check Roon. I really like the imersiv D-1, and I don’t regret purchasing it. I think the D-1 is a very high performing DAC. The SU-1 isn’t much to look at, but I am very impressed by its performance. I’m posting my perceptions not to cause a controversy. I like that I learned how transparent and high performing an inexpensive audio component can be. This experience has taught me to try to better understand why I hear what I hear when auditioning audio components and has motivated me to further investigate the science behind audio. I hope others who may be curious about why a component sounds the way it does will also be curious and investigate why, even with components they already own.

Awesome to hear!

 

[Waveform Fidelity]

You seem to be saying:

"I know that the difference from going to more than 24/48 can't be heard by a single human being on the planet - but I want it anyway"

I find that weird: To me, it makes no sense. It has nothing to do with boredom or excitement. I'm never going to get enjoyment by changing something I know neither I nor anyone else can hear.

It is just something I can forget about to focus on things that *do* matter for this hobby. That is where I find "fun and awesomeness" Pushing things to the limit that actually make a difference.

Using an analogy of the increasing resolution of modern displays……..

1080P used to be good enough

Now 4k is “good enough” from a ~ 1-2 m away, but up close i can still resolve the pixels, with the naked eye

Maybe 8K I need a magnifying glass (not sure never tried it) to see the pixels.

Eventually we will have resolution where the pixels can no longer be discerned

So, in my analogy (eyes/ears) 27 bits audio to hearing is like have a video display where you need an electron beam microscope to see the quantization -ha ha.

But, in a broader sense in Engineering, I think “good enough” or “just good enough” is like getting a D rating and where there is the opportunity to raise the technical bar it should be done, in my opinion.

But I completely agree with you, the case for adding more audio bits is not one of them.

 

[IPunchCholla]

But, in a broader sense in Engineering, I think “good enough” or “just good enough” is like getting a D rating and where there is the opportunity to raise the technical bar it should be done, in my opinion.

In engineering, exactly as much as you need and no more, is actually perfection. It is incredibly easy to overbuild or to underbuild. Building a design that is fit to purpose without waste? That is actually hard, but it is also what brings excellence to the masses. Adequacy is underrated.

 

[antcollinet]

Eventually we will have resolution where the pixels can no longer be discerned

The difference between video and audio is that in audio we have had the resolution that can no longer be discerned since the introduction of the CD over forty years ago.

 

[aagstn]

This test was harder than I thought it would be. At times I thought I heard differences in more complex music, but I believe I was inadvertently focusing on different aspects of the performance. I went back-and-forth multiple times and played segments less than 2 minutes long to try and better recall what I heard while still listening to a variety of sounds. The comparison was must easier with recordings of single instruments, such as solo acoustic guitar and solo piano in reverberant recording spaces where I could better focus.

This is where I always struggled with these types of tests sighted. I would be focusing to hear a difference and then not be sure if what I was hearing was just because I was listening closer. When I tried these types of tests with someone helping and not being sure of what device I was listening to it made me realize how much I was "hearing" with my eyes. My level matching was probably not exact either and I still couldn't tell DACs or Amps apart. My hearing is definitely a step down from most due to my age, but blind I couldn't tell the difference between a Burr Brown in an old DVD player and an AKM or Sabre in a newer DAC through a pair of Sennheiser 6XX. Now, I'm not saying this will be true of everyone. It is for me though and taught me not to throw away money on DACs and Amps since my ears can't even pick up noise that could be audible on older poorer measuring consumer DVD players.

 

[Waveform Fidelity]

In engineering, exactly as much as you need and no more, is actually perfection. It is incredibly easy to overbuild or to underbuild. Building a design that is fit to purpose without waste? That is actually hard, but it is also what brings excellence to the masses. Adequacy is underrated.

I respectfully disagree, and I can where your comment might apply in manufacturing with very low margins -consumer white goods, like washing machines is one example
.
I had a boss with that mentality to only build/design to a spec and no-more, drove everyone crazy until he left. In top R&D companies that I worked at “Good enough” is a very much frowned upon comment because innovative companies have the “pedal to the metal” on innovation and continuous improvement to stay ahead of the game to survive, so they are looking to score A+ not a “D”.

Imagine a car company that says, this carburetor and ignition coil/points are “good enough” for fuel delivery and ignition, so its exactly what we need and no more, and after all it meets the requirements. Following that reasoning engine technology would not have advanced, there would be no Intellectual Property industry, and everything would still be mediocre, or as you would say “adequate” Companies that have and do follow that mantra have/will always fall behind and become extinct. American car companies are one prime example of this playing out in the EV segment, and in my opinion its a cultural problem of incremental development, and “good enough” thinking.

There would be no Amazon overnight shipping, no 5G high speed service, no advances in medicine and the list goes on.

24bits/192kHz is so much more than “adequate” a choice made by the industry so that dynamic range issues are basically designed out for good.

Just my 2 cents……

 

[antcollinet]

because innovative companies have the “pedal to the metal” on innovation and continuous improvement

well run companies do this through marketing and technology development to identify the requirements for improvment - generating the specification for the product that embodies those requirements. And then developing the product TO THOSE EXACT REQUIREMENTS. The product development team should not exceed them because part of the requirement will be a cost level, Exceeding the technical requirements will typically make it impossible to meet cost requirements.

Fully meeting the design spec (all features, quality, time to market, cost) - *IS* A+. It is exceptionally difficult to do. Variations are the norm, not the exception.

Following that reasoning engine technology would not have advanced, there would be no Intellectual Property industry,

Again - all that is managed through technology development that then feeds into specified product development.

Sometimes you will get a product design engineer that comes up with a brilliant new idea that enables the team to achieve lower cost - or faster time to market. But it is only rarely possible to implement innovative new features actually during a product development project. Risk is too high and the processes of de-risking new tech would kill time to market.

In particular implementing features that offer no benefit to the customer (such as resolution he can't hear) would be categorically stamped on. This would take the result from A+ to E-. (Wasted time, effort and money)

 

[EERecordist]

Hello All! This is my first post to ASR.

I’ve owned the imersiv D-1 DAC for about three months.

Welcome to ASR. It is great to have new contributors! We have a whole psychoacoustics section, and several experts in psychoacoustics on ASR. Psychoacoustics would go to the audibility of harmonic distortion and other nonlinearities.

Personally, I would like to hear what respected equipment makers and mastering engineers use as test tracks, and what instruments/segments they use to judge systems.

I would say that the anti-aliasing filter in the early days, AtoD and DtoA, was not good, but I think that is corrected.

 

[Waveform Fidelity]

well run companies do this through marketing and technology development to identify the requirements for improvment - generating the specification for the product that embodies those requirements. And then developing the product TO THOSE EXACT REQUIREMENTS. The product development team should not exceed them because part of the requirement will be a cost level, Exceeding the technical requirements will typically make it impossible to meet cost requirements.

Fully meeting the design spec (all features, quality, time to market, cost) - *IS* A+. It is exceptionally difficult to do. Variations are the norm, not the exception.



Again - all that is managed through technology development that then feeds into specified product development.

Sometimes you will get a product design engineer that comes up with a brilliant new idea that enables the team to achieve lower cost - or faster time to market. But it is only rarely possible to implement innovative new features actually during a product development project. Risk is too high and the processes of de-risking new tech would kill time to market.

In particular implementing features that offer no benefit to the customer (such as resolution he can't hear) would be categorically stamped on. This would take the result from A+ to E-. (Wasted time, effort and money)

Well, yes I agree with most of ^^, but what I was referring to were technology companies that are already working on tomorrow’s technology that the industry implementer/consumers have not yet even dreamed of. Focus groups, market research etc, etc are moot - because people are pretty bad at imagining new stuff, good at incremental ideas, but poor of completely new ideas. Think of Steve Jobs telling people you won’t need a stylus with your touch screen phone, just use your fat finger, or Elon musk telling folks they will land a re-useable rocket booster back on a bobbing platform. These came from innovators, leaders not followers and not from some product requirement specs that others dreamt up (I have don my fair share of product development by the way).

Anyway, sorry I am way off the original topic, but neverthess an interesting exchange of points of view.

 

[Mano74]

You did the right thing with level-matching! In my experience it is much simpler and way more reliable to reach the required precision of better than 0.2 dB (ideally below 0.1 dB) with a multimeter in mV mode. Due to the DACs using different connections (balanced vs unbalanced), the voltage would have to be measured at the headphone output of the HPA4, which could be a bit tricky. Assuming that the headphone out and line out of the Benchmark are both controlled by the same volume pot, it could be OK to measure the line outs instead.


I'm not quite sure I understand the 10 dB difference, but I assume that is due to the balanced/unbalanced difference, right? So you needed to change the volume when switching DACs? If so, that is pretty cumbersome and limits your minimum switching time. 7 s would be pretty fast under those circumstances. In a perfect world, there would be some way to get that time to below 1 s, but I understand that this can be hard to do in a typical home HiFi setup.


Yes, listening comparisons at that level (where there is no difference or it is just bordering audibility) are extremely challenging. I am surprised each time people come here to claim that they "heard a night an day difference" between so and so while I - having done a couple of blind ABX tests - rarely had that impression with any subtle defect. That being said, due to our limited echoic memory, it is more revealing to play very short (< 10 s) but challenging sequences in quick A/B succession if differences are small. For larger differences like a broad dip in the bass or treble region (which would not be expected in a comparison of good DACs), longer music sequences can help distinguish the general "feel" of the songs in my limited experience. Though for most other characteristics, short + quick switches wins for me. But I understand that this is difficult and no fun when the switching itself takes 7 s.

Such a test is less of a music listening and more of a focused hearing exercise for me. Therefore, it's not pleasant like listening to a good track and more like actual work. I think most audiophiles don't want to put in the work or don't know that it is required and hope they will get the same result by casually listening to a few tracks and going "yep, heard that" - which absolutely does not work. You put in the work, which is commendable!


Awesome to hear!

Regarding the 10 dB difference, that was the SPL difference I measured between the DACs using the miniDSP EARS. It made performing the test quite a pain. I'd switch inputs on the HPA4, adjust the volume up or down by 10 dB, then switch the DACs on Roon. I made a number of mistakes, but I'd quickly catch them and start over. Eventually, I got pretty consistent going back and forth in about 7 seconds. It was an interesting experience.

 

[IPunchCholla]

I’m definitely more of @antcollinet’s take. I would call what you are describing as R&D. I work at a university and am routinely blown away by their abilities to come up with novel solutions to seemingly intractable problems, or just follow their curiosity down a rabbit hole with no known outcome. But I guess I don’t call that engineering. Might just be term usage.

 

[Waveform Fidelity]

I’m definitely more of @antcollinet’s take. I would call what you are describing as R&D. I work at a university and am routinely blown away by their abilities to come up with novel solutions to seemingly intractable problems, or just follow their curiosity down a rabbit hole with no known outcome. But I guess I don’t call that engineering. Might just be term usage.

Indeed, that could be it. In a University the R&D terminates (very often) in a published paper, in technology companies it terminates with a prototype design/algorithm to be validated, after which the next step is to commercialize it in a new product. Its the technology company driving the product and displacing what had come before, and its not originating from a “good enough” approach but a “do the very best you can” approach.

I think that where the debate started……seeking a good enough solution.

In my opinion the “good enough” approach is such a terrible metric on so many fronts. I have had colleagues that delivered “good enough solutions” which are barely above “barely acceptable” so its still a “D” in my book.

It does appear to be cultural too. In Germany for example auto repairs are first class, as is the workmanship in many trades. Here is the USA its not uncommon to have a contractor work on your home and do a crappy, poor job that breaks a few weeks later….. and you can hear them saying “its good enough job” in defence

So way off topic again… sorry

Way back in 2000’s do you think Cirrus Logic/analog devices did a market survey when they switched from 16bits/44.1kHz to 24bits/48kHz in their stereo codecs? or they just pushed the new technology down in to “chipset products” becuause they knew it was better?

Thanks again for the interesting exchange of points of view. I don’y have much more on this topic!

 

[IPunchCholla]

Indeed, that could be it. In a University the R&D terminates (very often) in a published paper, in technology companies it terminates with a prototype design/algorithm to be validated, after which the next step is to commercialize it in a new product. Its the technology company driving the product and displacing what had come before, and its not originating from a “good enough” approach but a “do the very best you can” approach.

I think that where the debate started……seeking a good enough solution.

In my opinion the “good enough” approach is such a terrible metric on so many fronts. I have had colleagues that delivered “good enough solutions” which are barely above “barely acceptable” so its still a “D” in my book.

It does appear to be cultural too. In Germany for example auto repairs are first class, as is the workmanship in many trades. Here is the USA its not uncommon to have a contractor work on your home and do a crappy, poor job that breaks a few weeks later….. and you can hear them saying “its good enough job” in defence

So way off topic again… sorry

Way back in 2000’s do you think Cirrus Logic/analog devices did a market survey when they switched from 16bits/44.1kHz to 24bits/48kHz in their stereo codecs? or they just pushed the new technology down in to “chipset products” becuause they knew it was better?

Thanks again for the interesting exchange of points of view. I don’y have much more on this topic!

I think we are actually in agreement (though many things developed at university are actually developed into products, sometimes via the selling of IP, but also through collaboration, or straight up development.

Adequate and good enough are not equivalent to me. Good enough is almost Ironic, usually meaning barely sufficient (or actually insufficient while appearing barely sufficient). Adequate means it does exactly what it was intended to, no more, no less. Adequate is absolutely part of striving for the best, but it is also something far more than that. Its define the limits and pushing the knowledge so you can take those ground breaking inventions to life/market in the most efficient way possible. Steve Job's might have shepherded the iPhone to life, but it was the supply chain engineering (amongst many other things) that allowed it to make so much money for Apple, it actually didn't introduce any new technology, just combined them into a package that fit Apple's vision. I believe there is something beautiful in doing exactly what you set out to do with an absolute minimum of waist or sacrifice that tends to be under appreciated sometimes, is all. I'm definitely not advocating for settling. Anyway, way off topic, but thank you for the convo!