MitchAlsup <MitchAlsup@aol.com> writes:

> On Wednesday, January 11, 2023 at 3:49:57 AM UTC-6, Terje Mathisen wrote:
>
>> Thomas Koenig wrote:
>>
>>> Terje Mathisen <terje.m...@tmsw.no> schrieb:
>>>
>>>> This is where my signal processing background steps in and says:
>>>> Start with the 24 bits/sample, 48 KHz master, and compress that
>>>> with aac/ogg down to something a bit less than CD bitrates, maybe
>>>> ~50% which is what you typically get from the lossless CD
>>>> compression formats.(FLAC?)
>>>
>>> What about the properties of the low-pass filter you will need
>>> before digitizing? Aliasing higher frequencies into the audible
>>> range can really spoil hearing experience...
>>
>> By definition, the master digital recording have already applied that
>> lowpass filter, right?
>
> It depends, the sound of a cymbal (for example) depends on a lot of
> phasal information not just the frequency spectrum coming out.
> Phase information invariably gets screwed up when you add analog
> filters to the signal path. This phase information depends on where
> on the cymbal the drum stick hits, its velocity and acceleration at
> the instant of contact.
>
>> Back in the analog days we had the same absolute limits on what the
>> recording microphones could physically react to, as long as you sample
>> that signal at more than 2X the highest frequency you will be OK.
>
> Microphones are just a first step in destroying the musicality of
> sounds in the recording process. Just out of college we setup a
> cording/playback studio in a room which was essentially acoustically
> perfect. We had a string quartette come in and play in the
> preferred position of the room, recorded with several of the best
> microphones available, onto a 16 track tape at 48" per second. The
> playback was through a very high quality preamp a powerful high
> fidelity amplifier into Dahlquist electrostatic speakers. There was
> something like $15,000 (1976) in that playback system, and sill the
> sound was far from "real"--remember we had access to the string
> quartette live and in person and were listening within a minute of
> hearing it live.
>
>> If your master is using 24 bits/sample @ 96 kHz then you will
>> surely be well above any need for phase-changing lowpass filters,
>> and you can still use lossy compression to get down to or below CD
>> bitrates with far higher quality.
>
> Even essentially perfect analog systems have already lost the "real"
> parts of musicality--digital cannot do any better at any bit depth
> and digitization rate.

I am skeptical of this conclusion. It's hard to do really good
experiments in psychoacoustics, even with excellent equipment.