Some thoughts on ASR and the reviews

Hi Amir,

Hi Andy.  😀

Does the 1KHz tone that you measure on the DAC, does it tell you how good the bass is or how sweet the treble sounds? 

That's like asking me if there is a traffic counter that counts how many UFOs go by.  First you have to show that there is such a thing as "sweet treble."  If you mean rolled off treble, sure, the frequency response tests show that different filters have the ability to roll off high frequencies, making the sound softer which some people confuse with "analog sound" and I guess "sweet treble."

Here is sample DAC measurement data on that:

As you see, there are two filters that roll off starting as low as 12 kHz.

Do you have a test for these as well?

See the test for treble above.  For bass, I do run sweeps down to 20 Hz and often problems are seen there, sadly in high-end DACs such as the aforementioned PS Audio DirectStream DAC

 

This one gets you coming and going with rising distortion at both ends of the spectrum!  My listening tests confirmed the same with problem identified by the designer as cost cutting on the output transformer (in a $6000 DAC!!!).

Here is another expensive DAC, the TotalDAC D1-six which retails for whopping $14,000:

 

See how it either accentuates or attenuates high treble depending on filter setting.  

We can see lack of fidelity in how it handles SMPTE IMD tests which has 60 Hz+7kHz components:

Pretty sure this a "sour" treble instead of sweet.  😁

This is what its frequency sweep looks like:

 

Dude! I’ve had many other speakers 

How many is that exactly?  I have measured and listened to nearly 300 speakers of every kind possible.  

you a dummy!! Go measure a dac. 

I measure, review and listen to almost every audio product other than subwoofers.  I test speakers, headphones, phono stages, preamps, poweramps, headphone amps, cables, audio and power tweaks, DACs, ADC/audio interfaces, DSPs, room EQ, etc.  I am nearly 2000 audio products reviewed in just 5 years or so. 

You put forward a specific argument and I showed using stereophile that your comments are inconsistent.  You have no answer for that?

I am not surprised that i am the only one here Amir do not dare to answer...

Perhaps i am a bit too hard on him with real arguments with real science articles against his main claims...The others attack him on a ground ( his gear specs measures) where no decisive win is possible against him, they gave him " the cable "he need to win easily ...

Why not discussing what  hearing a sound quality means in acoustics?

Acoustics rule audio and gear design not Amir measures....

😊

 

Now read this attentively and you will learn why Hans Van Maanen is not in the ASR team but in science :

I read it.  Here is quote at the end:

As the work reported here is partly based on theory, partly based on experience, further experiments should determine if temporal decay can be used as a semi-quantative parameter for the perceived sound quality. It is not within my possibilities to do much experimental work on a scientific basis.

So no controlled testing to see if any of the assumptions in the paper are correct.

Disregarding non-linear distortions, the frequency response between 20 Hz and 20 kHz of a system is very often taken as a major parameter determining the quality of a sound reproduction system.

Disregarding distortion?  That is the very topic we are discussing.  I am showing measurements of distortion.  If that is out of the scope for this paper, why cite it?

That aside, I measure frequency response way higher than 20 kHz.  Here is an example, the JDS Atom Amp 2 Headphone Amplifier Review

This is a $129 headphone amp from an American company whose response keeps going past 100 kHz -- 5 times higher than human hearing.

It is trivial for many audio devices to have such wide bandwidth so it is not at all a test of how good an audio device is by itself.  

The temporal decay of high-end analog audio systems is higher than the decay of digital systems in their present version and consequently the temporal "smearing" of the formers is less.

Where is the evidence of this?  The paper defines a metric but never shows measurements of such in any audio device, high-end or otherwise.  What is the point of that metric if we are just going to assume certain systems are perfect at it?

One of the better ways to compare analog and digital systems is by listening to a good copy of an analog recording on disc and the CD made of the same master tape. If the digital re-processing would not audibly effect the signal, no difference would be perceivable. Yet, on a high-end audio system, using e.g. electrostatic loudspeakers for the midrange and high frequencies, the transparency and clarity of the analog version (half-speed master copies) invariably showed to be better.

Where is example of such content and controlled testing demonstrating that?  "Shown" how?  Where is his metric for either one of these systems?

Comparing loudspeaker systems is one of the most difficult and tricky aspects of audio. Yet, generally speaking, the loudspeakers sounding best are those with the highest temporal decay. To mention some examples: electrostatics, ribbon tweeters and last-but-not-least ionophones.

"Generally speaking?"  What does that mean?  Where are the real tests that show this?  Controlled testing shows that Martin Logan speakers sounding poor compared to traditional speakers due to resonances and non-flat frequency response.  Does he have results otherwise?

Here is a controlled study: 

 

"M" is Martin Logan electrostatic speaker.  Here is the preference ratings:

 

It finished dead last.

High-end audio systems often sound better with analog recordings than with digital ones. This is at first surprising because of the very high quality specifications of digital systems. But the temporal decay is one of the few points at which analog systems beat their digital counterparts and it is thus a clear hint of its importance.

Again, claims made without any evidence and lacking his own metric through any kind of measurement.

Netting out, his metric relies on bandwidth. The more the better.  It has little to nothing to do with the discussions we are having.  Nor is there any evidence or data that such a metric helps perceived fidelity.

 

@erik_squires - yes, the humour didn’t go unnoticed 😂 - my thanks was badly timed, I had meant to post it sooner, but didn’t get round to it. It was also perhaps, for the many other posts you have made over the years that I learned from but never acknowledged - audiogon may have its little battles and disagreements, but my journey of listening would never have been made if not for voices like yours and many others. I am a very new audiophile, made wise by the experiences of the many. Thanks again for it all 😉🙏🏻