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Did Amir Change Your Mind About Anything?

It’s easy to make snide remarks like “yes- I do the opposite of what he says.”  And in some respects I agree, but if you do that, this is just going to be taken down. So I’m asking a serious question. Has ASR actually changed your opinion on anything?  For me, I would say 2 things. I am a conservatory-trained musician and I do trust my ears. But ASR has reminded me to double check my opinions on a piece of gear to make sure I’m not imagining improvements. Not to get into double blind testing, but just to keep in mind that the brain can be fooled and make doubly sure that I’m hearing what I think I’m hearing. The second is power conditioning. I went from an expensive box back to my wiremold and I really don’t think I can hear a difference. I think that now that I understand the engineering behind AC use in an audio component, I am not convinced that power conditioning affects the component output. I think. 
So please resist the urge to pile on. I think this could be a worthwhile discussion if that’s possible anymore. I hope it is. 

chayro
amir_asr
777 posts
 

Years back, when Halcro first came to market, one of their claims to fame was that they had amps that were exhibiting such amazing measurements that they were ground breaking. No other manufacturer could deliver a product with the type of measurements that these amps delivered. Problem was that as soon as any reviewer with half a decent ear listened to them, they were pretty much dismissed as not good sounding at all!( even though JA and others did measure them and were astounded by what they found, which conformed to Halcro's marketing).

I don't know such history but the Internet does. Here is JA's review of Halcro DM38: 

Sound
"To this day, I have yet to hear any amplifier that equals the dm58's combination of complete neutrality, harmonic generosity, lightning reflexes, and a sense of boundless power that is difficult to describe," was how Paul Bolin summed up his experience with Halcro's dm58 monoblock. It also nicely describes my reaction to the dm58 when the review pair briefly spent some time in my listening room.

Ahem.  It is not going your way, is it?  :)  Continuing:

The dm38 didn't pale in comparison with my 18-month-old memories of the dm58s. "Awesome dynamics," I noted, after playing Prince's Musicology (CD, NPG 74645 84692 7) two times through after hearing Prince live at Madison Square Garden; "awesome!" 

[...]

Perhaps more important, as well as excellent macrodynamics—the differences between loud and soft and how consistent the amplifier's presentation was at the dynamic extremes—the dm38 also excelled at reproducing microdynamics. By this mean I mean how well it preserved the tonal and imaging differences among different sonic objects at different levels. 

[...]

The Halcro allowed me easily to identify how each instrument was contributing to the combined tone, regardless of the speakers I was using.  At the risk of venturing into the semantic void, it wasn't just that the dm38 reproduced the sounds of instruments or voices with superb fidelity; it also excelled at reproducing the space between those instruments. Remember that the stereo image is an illusion, its fragility due to the brain's having to put aside what the ears actually hear in favor of reconstructing a simulated space between and behind the speakers.

 

Still not backing your claim.  But maybe it is this bit of subjectivity that you are hanging your hat on:

So, the dm38 combined great dynamics and great bass control with a superbly transparent view into the recorded soundstage. Its treble was free from grain and its midrange was as smooth as silk. However, I couldn't escape the feeling that the amplifier's tonal balance was on the lean, cool side. 

He ends with:

Summing up
It may be expensive, but Halcro's dm38 effortlessly joins the ranks of top-rated power amplifiers, not only for its sound quality but also its measured performance (not a given; witness some recent reviews). 

[...]

Like the dm58 monoblock, the dm38 is balanced toward the cool side of the spectrum—though I am sure Bruce Candy will argue that the Halcro amplifiers are actually neutral compared with the competition—so it will work best with speakers and source components that don't themselves sound lean. But with optimal system matching, the Halcro's effortless dynamics and astonishingly clean presentation will satisfy the listener's soul.

So this matches your definition of "they were pretty much dismissed as not good sounding at all!"???  Really? He couldn't gosh any more than he did.  Was he wrong about all of the above?  That it can satisfy your soul?  

How about this other reviewer:

Conclusion
The Halcro dm38 is among the best amplifiers in the world at any price. Its sound quality easily competes with the amplifiers from Krell, Mark Levinson, Pass Labs, Bel Canto, Spectral, Ayre, Boulder or any of the other players in the ultra-high-end market. At this level of performance, the sonic characteristics of the amplifiers become harder and harder to describe as they become closer to the proverbial "closer to the music" phenomenon. However, if forced to describe the Halcro's sound quality I find the Halcro sound to be similar to that of the Krell FPB series except a bit quicker and with less weight in the bass. For those in the market for a reference grade amplifier with the ability to resolve the slightest nuances, I strongly recommend a close look at the Halcro dm series.

This is your definition of bad review?  

No, companies go out of business because in high end audio, it is 80% marketing, 20% engineering.  Fail at the former and you go out of business.

somethingsomethingaudio
116 posts
 

A lot of fun to follow. A J you are looking weak! @soundfield are you going to take that!?

mahgister's avatar
mahgister
13,197 posts
 

Now a nail in the Amir coffin...

 

 

Magnasco and Oppenheim experiment demonstrated the nature of non linear human hearing and how the ears beat the uncertainty Fourier principle or the Gabor bounds and then why we need more an ecological theory of hearing than a hearing theory inspired By Fourier linear frequencies based methods ... the consequence of all this is that a set of linear measure used in design for the control and the good behavior of components CANNOT predicted a good sound experience only by the lecture of the number measured.. Amir for sure negated this fact and never adressed the fact that any measures must be interpreted in some hearing theory context to be meaningful and also compared with the set of all possible measures not only with the Amir  limited chosen sets..

 

 

But there is more to say ...

But what are the consequence of the non linear structure of the ears in the ways audio signals are treated by the ears ?

It turns out that a small amount of noise can improve the way the signals will be perceived... Yes you read it here and well...

Then "tweakers" and audiophile experimenting with cables can rejoice...😊

Good cable are not those measured by Amir after all...

All there is to tell to the ears is not in the perfection of a linearly PERFECT measured signals in the design process , not for the human ears..

it seems that the design process as said Van Maanen is more about noise and signals degradation CONTROLS than about inexistant linear perfection... Van Maanen called these controls the " Often disregarded Conditions for the correct
Application of Fourier Theory"... Amir claim his set of linear measures is perfect to tell all the story, no need for conditions for the correct application of Fourier theory ... As he said, Van Maanen is a fraudster trying to sell his amplifier... Amir him dont try to sell his method...😊

https://agilescientific.com/blog/2014/6/9/the-nonlinear-ear.html

 

read this short article :

Hearing, audition, or audioception, is one of the Famous Five of our twenty or so senses. Indeed, it is the most powerful sense, having about 100 dB of dynamic range, compared to about 90 dB for vision. Like vision, hearing — which is to say, the ear–brain system — has a nonlinear response to stimuli. This means that increasing the stimulus by, say, 10%, does not necessarily increase the response by 10%. Instead, it depends on the power and bandwidth of the signal, and on the response of the system itself.

What difference does it make if hearing is nonlinear? Well, nonlinear perception produces some interesting effects. Some of them are especially interesting to us because hearing is analogous to the detection of seismic signals — which are just very low frequency sounds, after all.

Stochastic resonance (Zeng et al, 2000)

One of the most unintuitive properties of nonlinear detection systems is that, under some circumstances, most importantly in the presence of a detection threshold, adding noise increases the signal-to-noise ratio.

I’ll just let you read that last sentence again.

Add noise to increase S:N? It might seem bizarre, and downright wrong, but it’s actually a fairly simple idea. If a signal is below the detection threshold, then adding a small Goldilocks amount of noise can make the signal ’peep’ above the threshold, allowing it to be detected. Like this:

I have long wondered what sort of nonlinear detection system in geophysics might benefit from a small amount of noise. It also occurs to me that signal reconstruction methods like compressive sensing might help estimate that ’hidden’ signal from the few semi-random samples that peep above the threshold. If you know of experiments in this, I’d love to hear about it.

Better than Heisenberg (Oppenheim & Magnasco, 2012)

Denis Gabor realized in 1946 that Heisenberg’s uncertainty principle also applies to linear measures of a signal’s time and frequency. That is, methods like the short-time Fourier transform (STFT) cannot provide the time and the frequency of a signal with arbitrary precision. Mathematically, the product of the uncertainties has some minimum, sometimes called the Fourier limit of the time–bandwidth product.

So far so good. But it turns out our hearing doesn’t work like this. It turns out we can do better — about ten times better.

Oppenheim & Magnasco (2012) asked subjects to discriminate the timing and pitch of short sound pulses, overlapping in time and/or frequency. Most people were able to localize the pulses, especially in time, better than the Fourier limit. Unsurprisingly, musicians were especially sensitive, improving on the STFT by a factor of about 10. While seismic signals are not anything like pure tones, it’s clear that human hearing does better than one of our workhorse algorithms.

Isolating weak signals (Gomez et al, 2014)

One of the most remarkable characteristics of biological systems is adaptation. It seems likely that the time–frequency localization ability most of us have is a long-term adaption. But it turns out our hearing system can also rapidly adapt itself to tune in to specific types of sound.

Listening to a voice in a noisy crowd, or a particular instrument in an orchestra, is often surprisingly easy. A group at the University of Zurich has figured out part of how we do this. Surprisingly, it’s not high-level processing in the auditory cortex. It’s not in the brain at all; it’s in the ear itself.

That hearing is an active process was known. But the team modeled the cochlea (right, purple) with a feature called Hopf bifurcation, which helps describe certain types of nonlinear oscillator. They established a mechanism for the way the inner ear’s tiny mechanoreceptive hairs engage in active sensing.

 

What does all this mean for geophysics?

I have yet to hear of any biomimetic geophysical research, but it’s hard to believe that there are no leads here for us. Are there applications for stochastic resonance in acquisition systems? We strive to make receivers with linear responses, but maybe we shouldn’t! Could our hearing do a better job of time-frequency localization than any spectral decomposition scheme? Could turning seismic into music help us detect weak signals in the geological noise?

All very intriguing, but of course no detection system is perfect... you can fool your ears too!

 

decooney
2,230 posts
 

@amir_asr Incredible that people with eyes wide open continue to claim that they only used their ears.

 

There you go again, making assumptions that everything is black or white and there is no such thing as "gray" in between. This is common engineer-only type of behavior and reaction. Its to be expected. Nobody confirmed we are only using our ears. Only you said this. We all see how you make up your own rules and conclusions, yet typically not respectful of others input when it comes down to it.

Sure we respect measurements. It’s a helpful guideline to test, measure, validate however we can, the best we can. Most everyone gets that Aamir. However, it does not encapsulate the whole spectrum of what some hear or don’t hear. I believe there is a long ways to go with scientific measurement, tools, and what’s going on with humans and hearing today. There are wild animals that hear and see things in the darkness that we cannot even begin to fully understand yet as humans.

One last thought - your measurement results do not always coincide with what we are hearing some times. Your definition of "perfect" is your opinion, not always fact for some of us here. This is something you will likely choose to continue to ignore. That’s okay. Everyone is entitled to their own opinion - whether you like it or not. That’s what makes for good horse races and keeps audio alive and well LOL.

 

 

somethingsomethingaudio
116 posts
 

@decooney maybe the most well put statement in this whole discussion 

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