[Arny Krueger[_4_]]

"Edmund" wrote in message
...

I haven't found a single piece of music with much higher frequencies then
22k

I posted them on the web for many years. I took the recordings down for lack
of interest.

and cannot find any information about any recording studio which advertise
to do so or even have equipment to do that. ( mics )

There are a few mics that are reasonably flat up to 50 Khz. It is hard to
make a mic that is useful for recording with flat response above that.

The world's recordists have not rushed to spend the extra money for mics
with response above 15-20 Khz, presumably because in their experience they
serve no purpose.

I borrowed a pair of mics with response up to 50 Khz and had them at my
disposal for more than a year. I made a few recordings with them, compared
those recordings to themselves with everything above various lower
frequencies removed. I found that it is generally safe to brick wall filter
off everything above about 16 Khz. The difference that makes is not reliably
audible by a number of people, even when using speakers with far more high
frequency extension.

Of course it is possible to record high frequencies with 176 kHz sample
rate
but I don't know what anti alias filters they use or what microphones.

The anti alias filters generally come with the converters and they have as
much bandpass as possible - about 96 KHz in this case.

I know of no microphones that are practical for use in general recording
practice that have response above 50 KHz.

I for one am still waiting for such real high res recordings. ( don't
know about SACD since I cannot make such files visible.... yet )

Of course, you won't find that kind of frequency response on analog
mastered recordings or on any Red Book CD, for that matter. That should
be obvious.

So we can forget HDtracks, where I find mostly ( only ?) old analog
recordings.

The interesting thing is that there are all sorts of glowing reviews for
many of those recordings, some from prestigious reviewers. As long as they
thought the high frequency response was extended, they heard better sound.
Is your skeptic's bone itchnig yet? ;-)

BTW I've reviewed this matter with John Atkinson and he remains silent with
neither apology nor explanation.