[ProAudio] The High-Resolution Challenge

[Dan Lavry]

I am not saying that 48KHz is better or worse than 96KHz. Clearly at 44.1Khz the theoretical bandwidth is 22.05Khz. That is already a couple of dB loss at 20Khz. Add a 20Khz mic for another 3dB, and perhaps a speaker for another 3dB.. pretty soon you find it to be difficult to accomodate the 20-20Khz hi fi standard. Do you recall the bandwidth of the mics used in the organ recording? It seems to me that too much is attributed to figuring sample rate, which is a step removed from the question of what we need for bandwidth.I undestand that it us not intuitive to understand that you only need to reach some minimum number of samples for a given bandwidth, and more samples do not add any information for perfect reproduction of the original. I wrote a whole 32 page paper Sampling Theory, based on Nyquist work, but some folks can't shake the notion that the more is better....RegardsDan LavrySent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Mike via ProAudio <proaudio at bach.pgm.com> 
Date: 2/14/20  12:26 PM  (GMT-08:00) 
To: proaudio at bach.pgm.com 
Subject: Re: [ProAudio] The High-Resolution Challenge 

On 2/14/2020 Dan Lavry<dan at lavryengineering.com> wrote:> The focus on sampling rate is somewhat backwards. The question is what is the needed bandwidth. In theory, and not too far from practice, all one needs is to sample at twice the bandwidth.? And the real question is the pluses and minuses of including high frequency energy that is above audibility. . . . . . .  Make sure that you include what you hear, and don't include anything at higher frequencies.Several years ago, there was a company that was making large electronic organ systems based on samples. The cheap version used 48 kHz samples, but if you wanted the really accurate thing, they had a set of 96 kHz samples, and that's what they were pushing. At the time, they needed a rack of 6 or 8 PCs in order to get the polyphony at the 2x sample rate. They way they justified it was that they were sampling individual pipes, not individual notes or stops (combinations of pipes). There was some  >20 kHz energy coming from the pipes, and when playing multiple pipes, those ultrasonic frequencies combined to produce frequencies in the audible range. So it's a way of getting what you'd hear if you played two pipes at once.The company didn't last very long, at least not in that business. But I accepted it as a fair justification for the 2x sample rate, given their goal.-- For a good time call http://mikeriversaudio.wordpress.com_______________________________________________ProAudio mailing listProAudio at bach.pgm.comhttp://bach.pgm.com/mailman/listinfo/proaudio
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