Why HiFi Gear Measurements Are Misleading (yes ASR talking to you…)


About 25 years ago I was inside a large room with an A-frame ceiling and large skylights, during the Perseid Meteor Shower that happens every August. This one time was like no other, for two reasons: 1) There were large, red, fragmenting streaks multiple times a minute with illuminated smoke trails, and 2) I could hear them.

Yes, each meteor produced a sizzling sound, like the sound of a frying pan.

Amazed, I Googled this phenomena and found that many people reported hearing this same sizzling sound associated with meteors streaking across the sky. In response, scientists and astrophysicists said it was all in our heads. That, it was totally impossible. Why? Because of the distance between the meteor and the observer. Physics does not allow sound to travel fast enough to hear the sound at the same time that the meteor streaks across the sky. Case closed.

ASR would have agreed with this sound reasoning based in elementary science.

Fast forward a few decades. The scientists were wrong. Turns out, the sound was caused by radiation emitted by the meteors, traveling at the speed of light, and interacting with metallic objects near the observer, even if the observer is indoors. Producing a sizzling sound. This was actually recorded audibly by researchers along with the recording of the radiation. You can look this up easily and listen to the recordings.

Takeaway - trust your senses! Science doesn’t always measure the right things, in the right ways, to fully explain what we are sensing. Therefore your sensory input comes first. You can try to figure out the science later.

I’m not trying to start an argument or make people upset. Just sharing an experience that reinforces my personal way of thinking. Others of course are free to trust the science over their senses. I know this bothers some but I really couldn’t be bothered by that. The folks at ASR are smart people too.

nyev

No it is not.

You could convert the phase noise from say a 1kHz tone to jitter in time domain, but jitter measurement is easier to measure in time domain.

Measuring phase noise will need a fairly expensive piece of equipment to do it right, but a more affordable real time scope can do the job better.

Also to measure phase noise you need a pure sine wave.  But in time domain, you 

could do it using a square wave or some transient waveform, which is more akin to real music.

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@andy2 

Also to measure phase noise you need a pure sine wave.  But in time domain, you 

could do it using a square wave or some transient waveform, which is more akin to real music.

That will be impossible when you are measuring the output of the DAC and have no access to signals that are hidden inside a box or hidden inside a chip. The only way is to measure the analog output. Fortunately that is something that can and is done with very good accuracy.

 

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prof

Sure, that’s fine. Except that opinion offers no justification for your characterization of Amir’s position, re any specific instance where he didn’t listen.

The specific instance - something we debated at the time - is immaterial. My opinion, which I need not justify to your satisfaction, is that a review of an audio component that doesn’t include listening is of little to no value. And we all know that Amir doesn’t always bother to listen, and has extensive, wordy rationalizations to justify that. He has lots and lots of words.