Re: Ultrasonics - being more specific


Subject: Re: Ultrasonics - being more specific
From: Philippe-Aubert Gauthier (Philippe-Aubert.Gauthier@USherbrooke.ca)
Date: Tue Oct 05 2004 - 08:09:13 EDT


Also take a look at your microphone (some are designed for ultrasonics) and
preamp specifications.

David Greisinger have demonstrated that some sound cards pretending to record ŕ
96kHz was just in fact interpolating between lower sample rate analog/digital
conversion. I think that when he called to sale office to say something like
"Hello I am Mister Griesinger (you know, the Lexicon reverb, that's me!) and
your sound card is not making 96kHz but its writen on the package" he then get
such an answer "Oh yeah, we know but the electronics chips can make it record
at 96kHz but its not implemented" or "Yeah, but we filter everything above
22kHz before ADC." I don't remember the sound card name, but it was a popular
and common one!

So : we should not even trust the specs!

Selon Ryan Torchia <torchia@buffalo.edu>:

> Max/MSP will do it in realtime too, and wouldn't require any additional
> hardware, although you'd probably need specialized hardware to record
> 18-48kHz.
> --Ryan.
>
> Coryn Smethurst wrote:
>
> >Thanks for this, but I was hoping someone knew of a program which didn't
> >need additional hardware, so I could use it out and about with my Apple
> >Powerbook - my fault for not being more specific. Does anyone know of a
> >program which would fulfill my requirements?
> >
> >thanks as ever
> >
> >crrs
> >
> >on 3/10/04 14:29, David Mooney at moko@city-net.com wrote:
> >
> >
> >
> >>Kyma could do this in realtime.
> >>
> >>Coryn Smethurst wrote:
> >>
> >>
> >>>Does anyone know of a program which will filter out frequencies below
> about
> >>>18khz then transpose frequencies above this threshold into the audible
> range
> >>>preferably real-ish time? The software would obviously have to cope with
> a
> >>>96khz sampling rate. I'm a Macintosh user ...
> >>>
> >>>Any help appreciated.
> >>>
> >>>crrs
> >>>
> >>>
> >
> >
> >
> >
> >
>
>
>

%====================================================================%
% Philippe-Aubert Gauthier, B.Ing, M.Sc. %
% Étudiant au doctorat en reproduction de champs acoustiques %
% %
% GAUS (Groupe d'Acoustique et de vibrations de l'Université de %
% [ Sherbrooke) %
% CIRMMT (Centre for Interdisciplinary research in Music, Media %
% [ and Technology) %
% %
% http://www3.sympatico.ca/philippe_aubert_gauthier/acoustics.html %
%====================================================================%



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