Audio Science Review = "The better the measurement, the better the sound" philosophy

 

https://www.biline.ca/audio_critic/mags/The_Audio_Critic_20_r.pdf (page 16 on)

Italics mark content contributed by crymeanaudioriver

A lot of trash in this collection of articles unfortunately.

I see it differently. Sure, we learned quite a bit since these articles were written. Yet, the time during which they were published marked presence of many amplifiers designers and manufacturers in North America. They knew what they were talking about.

Interesting that you linked to the specific article on the power cube. They say in that article,

We do not perform such separ-
ate IM distortion tests here because they characterize the
same nonlinearities identified by the THD tests. A non-
linearity that gives rise to a high 20 kHz THD will also
cause inband distortion products in a multitone test. A
full-scale 20 kHz test has the advantage that it has the
maximum rate of change of any inband test signal and it
characterizes both even- and odd-order nonlinearities
[Borbely 1989], [Jung 1979]. Transient intermodulation
effects [Otala 1970] are also covered in this test.

I assume you agree with all that written above as well, or only what suits you?

A typical “moving the goalposts” / “straw-man” rhetorical manipulation. That discussion of IM correlation with THD is still conducted in the context of the amp’s linearity under best conditions, not in the context of the linearity of system comprised of amp+speaker.

The article you link talks, often, about the performance of the current limiter inside the amplifier. If the amplifier is running into a current limit, it is clipping. If you are running your amplifier into clipping, then you are beyond the limits of the amplifier.

Current limiting occurs in amps without specific current limiting circuits too. As an example, a heating up power transformer coil may in effect serve as a current limiter. Another example is insufficiently sized capacitive power bank.

Look at the curves of THD vs output power characteristics of amplifiers, and you’ll see that typically, there is a rise in THD (and by extension in IM) long before the amp clips. The degree of such deterioration is typically frequency-dependent too.

This is indeed one of the mechanisms explaining the phenomenon of some of the amps distorting significantly more while they are connected to a speaker compared to when they are connected to a dummy resistive load.

Note the only example they show of oscillation, the issue yielded by non-resistive tests, shows oscillation occurring at 2 ohms, 60 degrees, and 1 ohm 30 and 60 degrees. This is important as it relates back to this article on ASR you linked:

Yes, occurrences when a commercially sold amplifier becomes unstable and turns into a generator while connected to a specific speaker are rare. Even though, the thread referred below has a description of a surprisingly common-case instance of that.

However, just like with the discussion of THD and IM, we need to take into account that the amp-speaker system can “ring” for some time, instead of turning into a self-supporting generator. Some of the replies in the thread below describe precisely such occurrences.

Complex Load for Power Amplifier torture testing

This specific issue is discussed, as they talk about how many speakers have both very low impedance and very large phase shift. The conclusion is very few.

Yes, this is one of the aspects discussed there.

The “conclusion”, if we were to derive any, is that in certain segments of the world market, predominantly preferring smaller speakers with simpler crossover topologies, there are indeed fewer opportunities for a given amp to exhibit ringing, and even fewer opportunities to exhibit runaway self-generation.

However, some of the replies highlight the fact that in some other  market segments, including that of affluent audiophiles, larger speakers employing exotic transducers and much more sophisticated crossovers are more prevalent, and thus the events of ringing and self-generation are much more probable.

Hence why the consensus that resistive testing into low enough impedance is sufficient.

There is no such consensus in that discussion. Interested readers can go there and see for themselves. I would roughly split the multitude of members posted there onto three categories:

1. Designers and restorers of amps from Western countries. They are for comprehensive testing with non-purely-resistive loads.
2. Designers of amps from China. They are for limited testing with non-purely-resistive loads.
3. Vendors selling amps made from pre-built blocks, Amir, and some of Amir’s followers. They maintain that testing on purely-resistive load is not ideal, yet good enough for predicting amp’s performance in 99.99% of cases.

Elsewhere there is a call to include 2 ohm testing which I think I have seen on some more recent tests.  It is probably important to identify from the articles linked that the worst issues are with tube amplifiers, lauded by audiophiles and rarely tested by ASR. When they are, the result is not positive.

Behavior of most amplifiers, including tube ones, does depend on the value of purely-resistive load, yet the change in behavior is much more predictable with the change in just the resistance value.

Thus, while testing on 2 ohm has its merit, it appears from the discussion that testing on non-purely-resistive loads is of more interest to people with practical experience in designing and repairing amps.

The other threads you posted from ASR are primarily not technical discussions about testing, but more banter from what appears to be the less technical members. Not everyone on ASR is technical.

Unless a member is an unscrupulous dealer pushing some version of snake oil, most of the “banter” deserves consideration, in my opinion. I give full credit to Amir for filtering out vast majority of such snake oil salesmen. However, the story doesn’t end there.

Similarly to doctors giving zero credence to patients describing their symptoms, and only relying on the results of locally available objective tests, amp designers and restorers only relying on simple measurements aren’t likely to keep their clientele for long.

Also, quite a few replies there were redacted: one can see quotations from them and references to them, but not the original replies in their entirety.

If you are going to participate in a thread putting down a web site you should probably learn how that site works, or at least the "Click to expand" button.

Ignoring your not so subtle attempt of slighting me, a person whom you obviously don’t know much about.

There is nothing redacted.

Once again, interested readers can go there and see for themselves. They’ll find the traces of reductions exactly as I described them.

The forum has a very good quote and reply system unlike another one I am thinking of.

Indeed, ASR runs on a more modern discussion platform than Audiogon. The “reply system” in practice also includes so-called moderation subsystem, or, in simpler terms, censorship features.

A discussion site without actively working moderation quickly devolves into pointless incomprehensible mess, mostly frequented by spammers.

Yet a discussion site with overreaching moderation generates its share of issues, both for regular members and site owners. I maintain that the ASR moderation has been such since about 2021.

Here we differ too. As technical as the dedicated ASR discussion thread was, it didn't touch on stochastic behavior of non-linear time-dependent systems, of which a practical multi-transducer loudspeaker is a prime example.

Attaching such a system to an approximately linear, approximately time-independent power amplifier leaves the combined system still non-linear and time-dependent.

The math describing non-linear time-dependent systems is far more sophisticated than the one underlying the simple measurements that Amir uses.

At first, that appears to be a lot to unpack. However, it can quickly be taken as a deflection. The topic at hand is the test of amplifiers. Specifically in this case resistive testing.

Nope, topic at hand is relevance of the testing Amir does on specifically power amplifiers to the subjective perception of audible distortions contributed by amp A vs amp B when connected to a specific speaker.

Note that I don’t discuss Amir’s testing of DACs, which I personally find entirely satisfactory and providing huge value to the community.

Neither I discuss Amir’s testing of loudspeakers, which Amir positions as in effect partial, only providing about 70% of information needed for a purchasing decision.

My position, as is the position of majority of ASR members with practical experience in designing and repairing power amplifiers who cared to express their opinions, is that the testing Amir has been conducting is marketed as more definitive than it shall be based on scientific understanding of the limited nature of the tests.

Attaching such a system to an approximately linear, approximately time-independent power amplifier

This negates all the other words used in the last paragraph. By your admission, the amplifier is time independent, approximately at least. That a speaker is not, is not relevant to the discussion.

OK, let me give you another analogy. Imagine if we assigned championship titles in boxing based on tests involving a boxer and a punching bag.

Boxer would be performing prescribed sequence of moves of varied amplitude and frequency, and we would be measuring, let’s say, acceleration of the bag’s center of mass in relation to the ideal acceleration expected at the execution of a specific move.

Case (A). A very heavy bag - let’s say weighting 8 times the average human weight - would approximate a linear time-invariant system pretty well. That’s an analog of 8 Ohm purely resistive load. Whatever the boxer does would translate pretty unambiguously into the bag’s acceleration.

Case (B). A lighter bag, let’s say ½ of the average human weight, would sway under the punches, thus failing to remain a linear time-invariant system from the boxer’s point of view, yet it would be still somewhat predictable. That’s an analog of ½ Ohm purely resistive load.

The geometry of the bag and the rope it is suspended on would now influence the system dynamics stronger. An audiophile analogy would be thermally induced deviations of the load resistance value, and parasitic capacitance of the cable leading to the resistive load.

Case (C). Now imagine that instead of the single heavy bag, the boxer would be punching a system of four bags: one of them, still somewhat heavy, used for punching, and the other three with differing weights interconnected with the first bags and between each other with a system of springs, ropes, and pulleys. In addition, the ropes would be threaded through a system of friction pads, with friction coefficients strongly dependent on the pads temperatures.

The goal of the boxer remains the same: the center of the mass of the bag he is punching must exhibit a specific pattern of acceleration. Only now the bag is also pushed and pulled by other swinging bags via the springs and the ropes threaded through friction pads and pulleys. This is analogous to how an amp must work when attached to a practical speaker.

Obviously, the task of boxer in case (C) is more complicated that in case (A). And the champion of case (A) won’t necessarily be the champion of case (C). The testing of power amps Amir is doing is analogous to case (A). What audiophiles are interested to know is analogous to case (C).

The only relevance would be if speakers drifted from a maximum of 30 degrees phase shift to 60 degree when they got hot and this is not identified in the ASR discussion linked. Is that what you are claiming? 

Indeed, thermal drift of a transducer coil resistance value due, to ,say, a loud music passage, is a factor that a good amplifier must somehow compensate for. Yet even if we remove the friction pads in the system of bags described above, its behavior will remain pretty sophisticated, and very different from a behavior of a single heavy punching bag.

While being a crude analogy, the visuals of the system of bags give insights of where an amp testing close to perfect on a 8 Ohm purely resistive load could fail miserably on auditioning involving a specific sufficiently large and sophisticated loudspeaker.

One of the cases is simply running our of amp’s power supply current capacity. A music passage may be such that at some point all the bags will be moving towards the boxer, overwhelming him with the combined impulse.

Such deficient behavior is usually exhibited by amplifiers of all classes with power supply sized insufficiently relative to the speaker and music characteristics.

Audibly, such deficiency usually manifests itself as “lack of dynamics”. Once again, it may be not outright clipping, but rather increased distortions as the amplifier approaches its power limit.

Another case is quick stochastic oscillations of the bags,  excited by a complex music passage. It can overwhelm ability of the boxer to punch quickly enough to counteract the resulting irregular oscillations of the bag he is punching.

This type of deficient behavior may be exhibited on some music passages by certain class A, A/B, and especially class D amplifiers, with their open loop bandwidth insufficient to deal with such combination of the speaker and music passage.

Audibly, such deficiency may manifest itself as a lack of transparency, and timing errors, especially in music produced by dozens of instruments playing at once.

 

 

Taro Mochi 7.4 oz each Frozen Desserts - Walmart.com

https://www.walmart.com/browse/food/frozen...

@crymeanaudioriver , there you go!

[START BOOK]

I see it differently. Sure, we learned quite a bit since these articles were written. Yet, the time during which they were published marked presence of many amplifiers designers and manufacturers in North America. They knew what they were talking about.

It was a comment about how amplifier design and speaker design has progressed. To your point, we have learned a lot.

 

A typical “moving the goalposts” / “straw-man” rhetorical manipulation. That discussion of IM correlation with THD is still conducted in the context of the amp’s linearity under best conditions, not in the context of the linearity of system comprised of amp+speaker.

Pointing out that this whole discussion (not you specifically) seems to be about picking your facts, or what you think they are. I spent more time learning about the math today. One of the joys of being somewhat retired. I don't have the engineering chops, but I took more than a few nasty math courses on the way to my PhD. By testing down to 2 ohms, where only the rare speaker reaches, there is significant exploration of the vast majority of speakers impact on stability.

 

Current limiting occurs in amps without specific current limiting circuits too. As an example, a heating up power transformer coil may in effect serve as a current limiter. Another example is insufficiently sized capacitive power bank.

The article, nor I differentiated what was current limiting, however, I believe the two examples you gave are not. This comes back to the math above.  Some EE's could probably jump in on that.

 

Look at the curves of THD vs output power characteristics of amplifiers, and you’ll see that typically, there is a rise in THD (and by extension in IM) long before the amp clips. The degree of such deterioration is typically frequency-dependent too.

 

Even I know that is about how the amplifier is designed and feedback. The feedback goes down as the frequency goes up. Going back to the math I learned today, as the feedback goes down, the stability will improve.

 

This is indeed one of the mechanisms explaining the phenomenon of some of the amps distorting significantly more while they are connected to a speaker compared to when they are connected to a dummy resistive load.

 

I think you made that up. That does not make sense.

 

Yes, occurrences when a commercially sold amplifier becomes unstable and turns into a generator while connected to a specific speaker are rare. Even though, the thread referred below has a description of a surprisingly common-case instance of that.

If you mean tube amps, I noted that, and that ASR rarely tests them.

 

However, just like with the discussion of THD and IM, we need to take into account that the amp-speaker system can “ring” for some time, instead of turning into a self-supporting generator. Some of the replies in the thread below describe precisely such occurrences.

Which brings us back to the 99.9% of the time it does not happen. "Ring for some time"? You mean unstable. Again, even I know that. Perhaps you should not be the person trying to lecture me on this.

 

However, some of the replies highlight the fact that in some other  market segments, including that of affluent audiophiles, larger speakers employing exotic transducers and much more sophisticated crossovers are more prevalent, and thus the events of ringing and self-generation are much more probable.

 

This is conjecture on your part. Fortunately, we can test this theory as Stereophile tests a lot of expensive speakers. Wilson Alexx5? No issue. Sabrina? No problem. Sasha, Alexia? No problem. Magico, 4 models, worst was 3 ohm, -60 degrees, not extreme by PowerCube article. B&W 801 - no issues. Big Magnepan? Child's play.  Soundlab?  Normally fine, but you can make the Brightness control nasty. Infinity IRS, etc. not as bad as many make out to be. Saw a note that tube amplifiers were considered in their design.

I will stick with my 99.99% and that seems to extend well into audiophile speakers. The corollary is no amp vendor provides any detailed measurements and you are hoping you detect this fault in a listening test.

 

There is no such consensus in that discussion. Interested readers can go there and see for themselves. I would roughly split the multitude of members posted there onto three categories:

1. Designers and restorers of amps from Western countries. They are for comprehensive testing with non-purely-resistive loads.

Restorer John is the only "restorer" and he does not come across as technical as others. More a tinkerer.  As the conversation progressed as noted, the consensus (always detractors) was low resistance for sufficient for goals.

 

1. Designers of amps from China. They are for limited testing with non-purely-resistive loads.

All 1 of them?

 

1. Vendors selling amps made from pre-built blocks, Amir, and some of Amir’s followers. They maintain that testing on purely-resistive load is not ideal, yet good enough for predicting amp’s performance in 99.99% of cases.

By far the most popular being Bruno Putzey designs and B&O. Nice thing given these are modules, they only need to be tested once to cover all units that will use them. 

 

Behavior of most amplifiers, including tube ones, does depend on the value of purely-resistive load, yet the change in behavior is much more predictable with the change in just the resistance value.

That is not a logical sentence.

 

Thus, while testing on 2 ohm has its merit, it appears from the discussion that testing on non-purely-resistive loads is of more interest to people with practical experience in designing and repairing amps.

 

I went back and saw that only one designer felt very strongly about it and he designed car audio amplifiers. That is not surprising given what car audio people will connect.  Going back to the math I learned today, if the designer knows the transfer function, they can estimate with high probability if the amp will be unstable.  You may want to read this:

https://d1.amobbs.com/bbs_upload782111/files_28/ourdev_548669.pdf

I had to read it 3 times, but this is very interesting too.
https://linearaudio.net/sites/linearaudio.net/files/volume1bp.pdf     That pokes holes in all the so called arguments about feedback.

 

Unless a member is an unscrupulous dealer pushing some version of snake oil, most of the “banter” deserves consideration, in my opinion. I give full credit to Amir for filtering out vast majority of such snake oil salesmen. However, the story doesn’t end there.

No it does not, no more than the banter on "medicine" by people with limited knowledge of what they are talking about. It is akin to people here talking about feedback, even a 100 of them, compared to Bruno and his article.

 

Similarly to doctors giving zero credence to patients describing their symptoms, and only relying on the results of locally available objective tests, amp designers and restorers only relying on simple measurements aren’t likely to keep their clientele for long.

Good marketing often wins over good product, and audio is no different. The first thing doctors often, if not normally do after hearing about the symptoms is to run tests. However, unlike audio, where only the external presentation matters, the patient describing symptoms are often the only measurements we may have of what is happening internally.  The issue presents not when the patient describes their symptoms, but when the patient tries to force their diagnosis on the doctor, even when the tests indicate otherwise. The test is almost always correct. The listening part criticality is to ensure there are not multiple issues at play. The communication part is letting the patient think they had influence when they had none.

 

Ignoring your not so subtle attempt of slighting me, a person whom you obviously don’t know much about.

Once again, interested readers can go there and see for themselves. They’ll find the traces of reductions exactly as I described them.

I will use this definition of redacted as I think it is appropriate:

to edit (text) so as to remove or hide confidential or sensitive information:

There is no evidence of this. When someone quotes another poster, it is normal, as one would also do here, to cut out what the replyer considers extraneous content w.r.t. their reply. That is not redacting, that is editing.  I have not seen nor experienced ASR "redact" anything, though they will suggest less harsh language.

 

Indeed, ASR runs on a more modern discussion platform than Audiogon. The “reply system” in practice also includes so-called moderation subsystem, or, in simpler terms, censorship features.

All forums, with few exceptions, have moderation, including this one. If you label ASR censorship, then you have to label all others.

 

Yet a discussion site with overreaching moderation generates its share of issues, both for regular members and site owners. I maintain that the ASR moderation has been such since about 2021.

I only passively use ASR these days, so I will not comment on this. That was not my experience as of 2 years ago when I was still active, though I did find it at times toxic. I think alternate means, i.e. a sand-box for people who don't fit in would be more appropriate. However, I go back to my comment, that many of the commenters here would effectively be flat earth followers on a science site given what they write. Hence, I am not surprised by how ASR treated them and I don't think it is unwarranted.

 

Nope, topic at hand is relevance of the testing Amir does on specifically power amplifiers to the subjective perception of audible distortions contributed by amp A vs amp B when connected to a specific speaker.

Except we come back to 99.9% or more of amplifier / speaker combinations will not have stability problems, ASR does not test tube amplifiers often, and based on my research, however, limited, that even audiophile speakers do not commonly have extreme characteristics, then there will be no change, at the amplifier level, with almost all speakers.

 

My position, as is the position of majority of ASR members with practical experience in designing and repairing power amplifiers who cared to express their opinions, is that the testing Amir has been conducting is marketed as more definitive than it shall be based on scientific understanding of the limited nature of the tests.

I will only state that you have no provided any concrete examples of where this is the case, not even strong potential examples, though I have accepted tube amplifiers could be most at risk here.

 

OK, let me give you another analogy. Imagine if we assigned championship titles in boxing based on tests involving a boxer and a punching bag.

The geometry of the bag and the rope it is suspended on would now influence the system dynamics stronger. An audiophile analogy would be thermally induced deviations of the load resistance value, and parasitic capacitance of the cable leading to the resistive load.

Thermally induced variations in the load have no impact on the amplifier performance as you admitted it is effectively time invariant. Cable capacitance is very low, and with the rare exception, far in the past (was that Naim) has not been a real issue. One could argue there is no reason to have that low of capacitance.

 

The goal of the boxer remains the same: the center of the mass of the bag he is punching must exhibit a specific pattern of acceleration. Only now the bag is also pushed and pulled by other swinging bags via the springs and the ropes threaded through friction pads and pulleys. This is analogous to how an amp must work when attached to a practical speaker.

 

You are pushing me out of my comfort zone, but I will respond with what I know, what I read, and my newfound knowledge of the math of stability and feedback. Looks like those math courses were not single minded!  I read in one technical article that the electrical simulation models using resistors, inductors, and capacitors are both realistic and valid models of real speakers including the movement of the cones.  As these are all linear elements, at least for the purposes of our discussion, then they can be simplified to magnitude and phase.  Hence we are right back to our stability discussion and 99.9% it does not matter. Audiophiles may be interested. It does not mean their interest is relevant.

 

Indeed, thermal drift of a transducer coil resistance value due, to ,say, a loud music passage, is a factor that a good amplifier must somehow compensate for. Yet even if we remove the friction pads in the system of bags described above, its behavior will remain pretty sophisticated, and very different from a behavior of a single heavy punching bag.

This is not the purpose of the amplifier. How would it know it was the transducer coil, and not some other element.  This would be the job of the speaker designer to compensate for.

 

One of the cases is simply running our of amp’s power supply current capacity. A music passage may be such that at some point all the bags will be moving towards the boxer, overwhelming him with the combined impulse.

Testing power output at different frequencies and 8,4,2 ohms would cover your argument. Again, even I know what. Using a reactive load that is not the same as your speaker is not going to provide easy guidance.

 

This type of deficient behavior may be exhibited on some music passages by certain class A, A/B, and especially class D amplifiers, with their open loop bandwidth insufficient to deal with such combination of the speaker and music passage.

I feel this statement is made up. I don't think it based in theory or reality.

 

Audibly, such deficiency may manifest itself as a lack of transparency, and timing errors, especially in music produced by dozens of instruments playing at once.

But we go back to testing at 2,4,8 ohms, which is sufficient for 99.9% or more of speakers will provide all information needed on where the amplifier will clip, and testing with a reactive load will provide no additional information. How would you even related it to your speaker that you intend to use?

[END BOOK]

 

This is just me, learning as I am going, finding it easy to counter your arguments, some of which I have a high confidence are flawed.

 

Audio Science Review. Haha, I love that name. It's funny.

 

@crymeanaudioriver

You have neither proven the uselessness of ASR testing, nor have you provided alternatives

Sir you have been here rambling on for awhile now.

There has been NO ONE who says that measurements, ASR measurements or any measurements are useless!

Most seem to be like my view. They aid in the evaluation of equipment, but I do not rely on them alone.

What has been the issue from the 1st page is the culture of ASR!

And that to that, you keep reiterating their point again and again..ad nauseam.

For a man who flaunts his education, I would think you’d get it by now.

 

Amir don’t need a fanboy, fighting his battles.

@henry99 , if you didn't have only 9 posts, all in this topic, all effectively band-handed attacks on ASR, then I may take your post seriously. However, as you do have only 9 posts, all in this topic, I see no need to take you seriously. That would create an account, solely for the purpose of attacking ASR is definitely a point of interest. Education is important if you want to understand certain topics.

@crymeanaudioriver

 

The Infinity IRS wasn’t the amp killer, the kappa 8 and Kappa 9 were the amp killers.

@crymeanaudioriver 

 

if you didn't have only 9 posts, all in this topic, all effectively band-handed attacks on ASR, then I may take your post seriously. However, as you do have only 9 posts, all in this topic, I see no need to take you seriously. That would create an account, solely for the purpose of attacking ASR is definitely a point of interest. Education is important if you want to understand certain topics.

Yea, your right! 9 posts in 2 1/2 years.

You have what 72 posts in 1 week?

Silence is NOT a weakness, now matter how you want to spin it.

I am educated my friend, unlike you, I dont need to flaunt it.

Your still making my point however.

Someone stumbling onto this thread might feel like this:

 

All the best,
Nonoise

@henry99  Requoting you:

There has been NO ONE who says that measurements, ASR measurements or any measurements are useless!

Most seem to be like my (and Henry's) view. They aid in the evaluation of equipment, but I do not rely on them alone.

What has been the issue from the 1st page (of this forum) is the CULTURE of ASR!

And that to that, you keep reiterating their point again and again, ad nauseam.

For a man who flaunts his education, I would think you’d get it by now. (@crymeanaudioriver).  

@crymeanaudioriver - 

Please state for us what other names you've used on Audiogon. 

 

Tammy-

This guy is like a tick that burrows into Audiogon until he causes enough irritation to get booted out... Then comes back under another name and starts the process all over again. 

@fair

Thus, while testing on 2 ohm has its merit, it appears from the discussion that testing on non-purely-resistive loads is of more interest to people with practical experience in designing and repairing amps.

 

It is not in my review charter to help either camp in that.  That aside, I did build an emulator of a 2-way speaker per stereophile.  And used it for a bit of testing.  It didn't reveal anything useful so I retired it.

I have used real headphones for headphone amps.  That too was a useless exercise as the back EMF combined with the impedance of the amp produced completely erroneous and misleading THD measurements. Similar situation exists with testing amplifiers with speakers.

Even if something useful popped out, who is to say that speaker is representative of any other?  It may be a corner case, an easy case, or a difficult case. Who knows.

I do vary the resistive load to test for load sensitivity and report on that (usually a problem with low-end class D amps although some high-end ones suffer the same).

Finally, keep in mind that any speaker or emulated load of one would have to be at very low power.  There, distortion may not be material at all (swamped by noise).  This is why JA at stereophile only uses is load emulation for frequency response test.

Yes, there is a $15,000+ load cube that provides a couple of reactive loads (NOT representing any real speaker).  Audio critic had one but I think it blew up on them and they no longer used it.  I would spend the money if I thought it would add value but it simply doesn't.

Making sure this point is understood: there is a very high bar for adding more tests to the suite that I run.  Every test suggestion must come with strong justification which I have not seen in any of your posts.  Folks on ASR routinely make such suggestions.  You want a new test?  Come back with real data that shows usefulness.  "Would be nice" isn't going to work.  A lot of things would be nice but not when it clutters existing measurements and take time and resources form testing other products.

@boxer12 

Tammy-

This guy is like a tick that burrows into Audiogon until he causes enough irritation to get booted out... Then comes back under another name and starts the process all over again. 

What is the solution?  Ban them after a few posts when you realize they are going against the grain of the forum/thread?

@fleschler 

I do not trust @crymeanaudioriver opinion(s).   ASR site is replete with anecdotes and foolish statements concerning cables, especially digital cables.    I've tried half a dozen digital cables and none of them sound the same, not even close.  I bet they measure the same though, 75 ohms, similar capacitance, resistance, inductance although I have no tests proving that other than a voltmeter.   I decided based on listening.   None of the cables had specs although five had extensive explanations concerning their construction.  

My tests are extensive and include measuring the output of audio devices to see if the waveform has changed at all.  I recently started to play music through them and perform null tests showing the cable made no contributions whatsoever.

Reports like yours persist not because the facts are different, but that you think listening with your eyes wide open is the same as doing so without them.  Until such time that you can provide reliable evidence of sound only, what you are saying has no value.

One of the top audiophiles in this forum with half a million dollar audio system swore a few years ago that he can tell the difference between his MIT oracle cable and others.  He agreed to a blind test where he could not remotely do so. All it took was using just his ears to change the outcome.  You can read about it here: 

"So our results with Mike as our listener were clear: for this particular methodology, Mike could not accurately identify a difference in the cables."
 

Mike posts this about the experience: http://www.avsforum.com/forum/86-ul...184-observations-controlled-cable-test-2.html

"yes; i have, to some degree, changed my perspective on cable differences....but...my mind is still processing the results and what they mean for me. i hope that i can coherently relate the various thoughts that go thru my mind. as Chris mentioned; the controls were successful at keeping me from knowing which cable was which. for each test i felt confident about my choice (except #6...see below).
[...]
when i made my choice known for #8 i was confident that i was 100% for all 7. then my friend Ted said 'that's it.....test over'. we had discussed prior that any result 7 out of 10 or better or 15 out of 20 or better would mean a positive result and to continue. once we got to only 3 out of 7 it was clear that we were not going to get a positive result.

why did i fail?.....or put another way.....why did this test show no real difference? was i overconfident?

yes; regardless of the eventual answer i was not respectful enough of the challenge.

[...]

in my mind i am not confident that i will ever be able to hear reliable differences between the Monster and the Opus to pass a Blind test. OTOH i am also not sure i won't be able to do it."

----

Until this lesson is learned, nothing you know in audio can be trusted to be true.

“ What is the solution? Ban them after a few posts when you realize they are going against the grain of the forum/thread? “

https://i.gifer.com/Mtiv.gif

 

 

Hey, Amir is back and still trying to prove a negative.  Notice he continues to try to make his point with singular examples.  In this case someone who owns an expensive stereo.  Remember, Amir considers himself and anyone who has spent a lot of money on equipment an expert.  He just can't get over other people hearing things he cannot.  

Hey, Amir is back and still trying to prove a negative.

No, he is disproving a positive.

Notice he continues to try to make his point with singular examples.

Every positive claim that "I or a group heard cable difference " not using proper testing methods are also "singular examples".  He is pointing out those positive claims can be disproved with proper testing methods and have been . I have yet to see any proof to support that positive claim of hearing differences other than useless anecdotal stories.

And you will forever remain in that state because that is what you want to believe. Imagine someone who is color blind arguing there is no such thing as a green light on traffic lights.  

“Meanwhile back at the ranch, while the ranch hands predisposed to measuring the phallic prowess of the various stallions argue of its importance, the wise ranch hand is enjoying a leisurely ride though a beautiful meadow by a stream, sun lightly filtered through the branches of an imperfect tree, with the other ranch hands sweethearts.”

 

Sorry, couldn’t resist. I’m just stting here listening to Ellington’s masterpiece “Afro Bossa” through a pristine pair of NOS 211 vacuum tubes which, in all liklihood, measure horrbily next to the Topping amplifier du jour. Drive what you like because at the end of the day, nobody gives a darn but you.

@amir_asr

You want a new test? Come back with real data that shows usefulness.

Your site is to heavily censored for NEW data, NEW opinions, even NEW members that have an open mind. If you WANT the data, stop shutting down people who don’t agree with you and tear down the walls. Isn’t it annoying that you can’t host this thread or a similar thread (even the one you already deleted) on your site without kicking everybody out?

 

 

 

@kota1 Hey, ASR is Amir’s site to do with as he pleases and its a site that the ASR disciples obviously appreciate. Now, why on earth do they want to invade a neighboring country or vice versa? Most here have no desire to lean into their philosophy so why do they wish to lean into Audiogon’s? Can’t we all agree that we already picked our path? Those without a camp can pick the one they like and go there. If someone got banned from either site they likely had it coming based on the rules and norms of that particular site.

 

If people are listening to more music through Topping isn’t that great? Isn’t it also great if people are listening to more music through ARC, Wilson, Luxman, Devore, Audio Note, Shindo, Harbeth…

@ghasley , I love your analogy, we are "invading", good one. Uhhhh.. who is invading who?? This is a discussion among hobbyists, about a common interest. I am asking a question about professionalism, courtesy, and opening a discourse. Your point is extremely well taken that although Audiogon welcomes different opinions Amir is free to come here and express himself and then shut down and censor the same posts on his own site

The claim prove a negative is itself a negative claim and a self defeating statement. Imagine someone color blind arguing there is no such thing as a green light on traffic signals when the one they're arguing with rejects evidence and science that proves color blindness exists,  so to them there are no green lights anywhere. 

@tonywinga  I love your analogy of a color blind man not seeing green traffic lights.  If it weren't for their usual location at the top of the signal, he would be a danger on the road.  That's Amir. 

@Amir My tests are extensive and include measuring the output of audio devices to see if the waveform has changed at all.  I recently started to play music through them and perform null tests showing the cable made no contributions whatsoever.

Reports like yours persist not because the facts are different, but that you think listening with your eyes wide open is the same as doing so without them.  Until such time that you can provide reliable evidence of sound only, what you are saying has no value

HA HA HA!!!  He started to play music through them (I bet they weren't the digital cables I've tried and use) and couldn't find any contribution.  Hence, what I say have no value.  That's both stupid and funny.  I can't hear.  My opinion has no validity without measurements.  And here's a guy who can't hear differences in cables.  He obviously has a defective ear(s)/brain, really bad audio equipment/cables/system or listening capability.   I struck out your opinion because that's what I think of it and so does 90+% of this forums members think of it (ASR members posting negative opinions here make up most of the rest).  You have a tin ear!  Digital cables all sound the same-what a rube!

This has all gotten so booorrriiinnnggg.

Please go back to your sandbox, to which I hope is filled with quicksand. 

Time to shut this pig down.  

He obviously has a defective ear(s)/brain, really bad audio equipment/cables/system or listening capability. 

 

That is 4 cliches in one sentence. That is not something one should be proud of.

@fleschler +1, every post in this thread (even ones that disagree with you) seems to confirm your original thesis when starting this thread, congratulations! Over 1000 posts in this thread can’t be wrong, that’s how I measure the deal.

Yeesh.

Amir isn’t ’invading’ Audiogon.

 

Someone created a thread critiquing him and his web site, so he’s entered the thread to clear up misconceptions and answer questions. I think it’s great that he showed up!

Should we just keep this an echo chamber where criticisms are thrown around and never countered because "stay in your lane!" ??

Also, don’t speak for everyone: plenty of people here do not wish to fall for b.s. claims made by manufacturers and we are glad there are places like ASR which puts these (and other audiophile claims) under more rigorous scrutiny.   And I'm sure I'm not alone in appreciating Amir showing up here to disabuse misinfo.  Don’t treat Audiogon as some hive-mind of pure Golden-Eared subjectivism - the members span a gamut.

@fleschler 

My opinion has no validity without measurements.  

What?  I didn't ask you to measure anything.  I asked you to listen only with your ears.  And not with your eyes. 

I have repeated over and over again that listening tests are the gold standard over measurements.  You have spent a ton of time here posting.  In that much time you could have conducted many blind tests showing us how  your ears correctly identify one cable vs another.

As for my example, it was a concrete data point.  As I keep saying, we are fans of what we can prove and demonstrate, not just claim.  Will you follow or are folks supposed to believe an online person because he just says so? 

@fleschler 

And here's a guy who can't hear differences in cables. 

With my eyes open like you, and full of preconceptions, I hear the difference every day of the week and twice on Sunday!  I report the same in my reviews.  Problem is, when I close my eyes, the difference vanishes like a fart in the wind.  And that is what happened to Mike in that test.  So it doesn't matter which school of thought you arrive from.  Use only your ears and then conclusions are something we can talk about.  

Remember, there is a cost to you what you believe in.  Such fancy cables cost money that could be put to other use like buying more music, good food, etc.  So you best be sure when you insist that you are right.  Repeating misconceptions about me won't get you there.

@cindyment ​​​​​​@crymeanaudioriver  or your other 19 usernames. You are the Tick carrying Lyme Disease to forums. The rat that carries the plague. 

@Amir Keep your fans on ASR.  Can't hear differences in cables that measure the same=something is very wrong here.  One doesn't have to believe any online person; however, based on the enormous "subjectivist" opinions, people actually do hear differences, right or wrong, personal preferences included, regardless of measurements and decide to what sounds best to them, in a system, in a room.  Nothing you say will change that.  Your advice based on measurements is not something audiophiles/music lovers agree on because, apparently, they choose wrongly, equipment that doesn't measure up to your standards or is too expensive.  I listen in the dark with all lights off when I want to immerse myself in the music, just like a movie theater.  I don't see differences in sound, I hear them.  

Dismissive of older equipment not measuring as well as cheap current equipment is as wrong as dismissing older recordings because they used older technology with distortions and reduced resolution, etc. of tape versus superior hi-res digital.  

You think you are superior to nearly everyone who posts on Audiogon because your opinion is based on measurements (except when you don't find a measurable difference ala cables, tweaks, etc).  The overwhelming majority do not think so.  I am just one music lover with recording/performing experience and a high end audio reproduction system.      

I found this quite interesting and it appears the folks over at this site do quite a bit of testing. They seem to be very transparent about their test equipment, methodology and end goals in testing. They even make a statement as such.

@amir_asr what say you? I do not go on your site very often as the equipment you test is not of any interest to me. The question is are you as transparent in your net goals and testing criteria?

 

 

@juanmanuelfangioii +1  He tales the joy out of the hobby.  It is a hobby for most of us, not a vocation. 

I only accepted a small fee for one recording/mastering session out of 250+ recordings because I love music so much (sometimes performing as well) and being around so many creative people (composers of many movies and music loving actors as well).  

I am fortunate to have several friends who I consider to have golden ear hearing and two that have been employed in remastering of LPs for Kevin Gray and Chad Kassem's labels.  One finds digital recording just another format, the other hates it and sticks only to analog.  They both can detect anomalies/distractions in a sound system and possible solutions in acoustics and mechanical devices (not electronic) very quickly.   It's great to have those friends who are so picky about sound.  They have been nit-picking my system for decades but provided me leads on improving it to the state is in now which they say is all I need.  No guest leaves my house after listening without wanting to return to hear more.  I have to set time limits. 

What @fleschler said about Amir,

@Amir Keep your fans on ASR.  Can't hear differences in cables that measure the same=something is very wrong here.  .....   You think you are superior to nearly everyone who posts on Audiogon because your opinion is based on measurements (except when you don't find a measurable difference ala cables, tweaks, etc). 

Amir's exact words,

I have repeated over and over again that listening tests are the gold standard over measurements. 

 

How do we move forward if the same lies continue to be repeated?

How do we move forward if some audiophiles refuse to put their faith to the test and do a blind listening test?

@amir_asr I find it interesting that these Dutch lads could do speaker cable tests, find measurable differences and on the subjective side hear the difference in the various speaker cables.

May need to use your translation features for some of the pages.

Interesting these guys are testing some very nice gear. And do blind testing what ever your name is @crymeanaudioriver 

 

I found this quite interesting and it appears the folks over at this site do quite a bit of testing. They seem to be very transparent about their test equipment, methodology and end goals in testing. They even make a statement as such.

 

You consider it transparent, I consider it amateur. It is interesting that you consider this transparent, but do not give the same consideration to ASR. This was my first Google hit. The difference in level of detail and depth and quality of the information is not subtle.

 

 

only issue i have with his testing method is he never tests in actual use just isolated on his tester / bench. so, he won't see interactions of the components and how they affect each other just the raw test of the single component / cable.  No interaction of a speaker cable to the amp and speaker for example. no indication of issues with a component not liking the impedance or capacitance of a cable etc. Testing in isolation is only part of the story. 

Other than that, it's just more information to make an educated assessments prior to listening for yourself. 

Jonathan Swift would have had a field day with these guys.

@crymeanaudioriver as nonoise said you do dance on a pin head and that makes you.

Let the man speak for himself. No one here cares what you think.

You are the Deer Tick of the forums. (not my words but appropriate) 

Are you @amir_asr internet bodyguard? 

19 user names? 

As I said @amir_asr what say you? I do not go on your site very often as the equipment you test is not of any interest to me

@amir_asr 

Will you follow ?

Not everyone here agrees with you (shocking) and don't want to "blindly" follow.

Here is an article on audio equipment break in, why not ask Home Theater Review for their data and you can report back OK? Good luck with that...

 

@crymeanaudioriver and you are an expert on?

I thought you were a Phlebotomist or Respiratory Therapist ?

Or you are @cindyment the great audio designer that could not site one design. He or she was quite the expert on wine and cheese too, especially fromunda cheese.

@jerryg123 , nice post on the cable testing, thanks:

"What a bizarrely intensive, educational and special test this has been to do. The aim was to establish a link between measuring and listening. And that was partly achieved. The Top 3 based on measurements is largely the Top 3 of the blind listening test. Both the Shunyata (unanimous), the Van den Hul and the Audioquest were eliminated. However, the MIT (Martijn) and Driade (Yung) were also on the Top 3 list. So there was 70% overlap per author. Not a bad score. And with five cables in total - all scoring well - it is still a very neat score overall."

@fleschler 

 

One doesn't have to believe any online person; however, based on the enormous "subjectivist" opinions, people actually do hear differences, right or wrong, personal preferences included, regardless of measurements and decide to what sounds best to them, in a system, in a room.  Nothing you say will change that. 

Fleschler, that comes across as a dogmatic statement "You Can't Change Our Minds!"   Do you really want to seem that inflexible?  Isn't being open minded a two way street?  It often seems that people using a purely subjective ("Golden Ear") paradigm will castigate the "objectivist" for not being open to their claims, but will remain stubbornly opposed to being open to the objectivist side.

 

Also, you seem to be projecting your own attitude on to others.  It's simply not true that "nothing (Amir) can say will change" minds.  He, and others on his site, and other people on the internet over the years taking a similar view, have changed plenty of minds.  ASR is FULL of people who used to be in the "everything I think I hear is real" camp but who are taking a more critical look at the claims of many audiophiles and high-end audio companies.  

Honestly, not everyone is so close minded to the arguments and evidence presented by Amir.  Look at the huge number of comments under his youtube videos - it's full of incredibly appreciative comments!

 

He tales the joy out of the hobby.  It is a hobby for most of us, not a vocation. 

 

Again, please be aware this is speaking for yourself.  In no way does he take the "joy out of the hobby" for tons of people who appreciate the knowledge gained over on ASR.   He's not entering your listening room and taking away your tweaks, or telling you that you have to stop buying whatever you want. 

One could just as well complain that "all these audiophiles telling us everything needs break in" are taking the joy out of the hobby.  But...one is free to ignore this and take our own approach (and/or look at the evidence for such claims if we wish).

 

 

 

 

 

@jerryg123 ,

I looked over that "cable test" at Alpha Audio. I will reiterate my comment. It is very amateur. How can anyone call themselves and audiophile of any experience and not know even the most basic things about a blind test. They even have a video of them doing this blind test. They don't have a good explanation, so we work with the video and what they wrote. Apparently, all they did was listen to each cable only once, write down their notes, then gave a rating at the end. They could have put all the names into a hat and pulled them out to determine the ranking. The result would carry the same weight and validity. Based on their data, the Shunyata would have been the loudest.

@amir_asr perhaps you would want to jump in at this point, but I don't get a very strong impression these Alpha Audio guys have much idea about what they are doing. I don't have the confidence to solidly identify measurement mistakes, but some of the things they wrote have me shaking my head, this like this statement. How could any measurement they made provide any indication of material purity?

The conductance is purely indicative. It shows how pure the material is that has been used. Ricable claims to use very pure, 7N copper. That matches up pretty well with what we measure on 2 x 3 meters (we go out (+) and back (-) in the cable in this measurement). Shunyata tops that with the very purest copper. And so that is visible in this measurement.

 

 

Think it was said earlier that no one cares what a Phlebotomist or @cindyment has to say about anything.

Troll keeps a 🧌 ing.

@jerryg123 , someone on ASR spent more time evaluating their methods. The word amateur keeps repeating in my head. I will point this out to you as well @kota1 .

https://www.audiosciencereview.com/forum/index.php?threads/loudspeaker-cable-test-and-comparison.35712/post-1247963

 

The guy doing the switching is there. The two listeners discuss their findings which isn’t good methodology during the test. The switcher also had done the measurements. This isn’t even good single blind. Plus they discuss things for several minutes as cables are switched. They can see the cables being pulled out as switching is done. The first one was a white thin little cable, the next one is a big black fancy looking cable which they might have noticed even though not scrutinizing the cable as this happens. The switcher even gets involved in the discussions of what some of the cables sounds like with the test listeners. At one point even discussing what the measurements of the cable currently listened to was. This is a preposterous test. They are listening to not quite 10 minutes of music once, then talk amongst themselves for 7 to 8 minutes while cables are swapped (again in their view) before listening to the next one. And the results are random even though the author tries to spin it as meaningful.

 

@jerryg123 , did you notice how actual scientists don’t put pics of toys, like "piggy banks" in their cable reviews? Good example for the pretenders in this thread :)