>are both limited to a 96kHz recording sample rate(per the specifications
>I found via the above links), and are bandwidth limited to ~46kHz -3dB
>rating for recording. There are a number of audio cards that use
>brickwall filtering to limit high frequency response before the Nyquist
>cutoff is reached, so be sure to read the specs carefully.
Of course, these cards support the sampling rate of 192 kHz at playback
only. Recording is limited to a sampling rate of 96 kHz. But Pawel asked
for a playback system only (read the question carefully ;-). Recording is
a different matter. For recording ultrasonic signals up to 250 kHz, the
USB-based UltraSoundGate system (www.ultrasoundgate.com) would be one
choice.
> I suspect that both the sound cards mentioned have anti-aliasing filters
> on the outputs so it may not be possible to take full advantage of the
> high sampling rates unless there is a way of disabling or bypassing the
> filters. For example, the Audigy2 card is listed as having a frequency
> response of 46 kHz. I would be interested in hearing what sort of
> frequency response people have actually achieved with these new
> high-performance sound cards. Also, do they really give you 24 bits of
> signal-to-noise ratio? A common problem with high resolution A/D and
D/As
> is that electronic noise pervents you from getting the last few bits of
> performance out of the board.
As mentioned before, the maximum sampling rates are different in recording
and playback. You are absolutely right, due to the electronic noise floor,
the least bits of such a 24 bit sample can be ignored. The manufacturers
specify a dynamic rage of about 110 dB. That would correspond to 18.3
bits. So, the 5 least bits will cary no significant information (only
noise).
Cheers,
Raimund
----------------------------------------------
Raimund Specht
Hauptstr. 52
13158 Berlin
Germany
phone/fax : +49 30 9163758
[EMAIL PROTECTED]
www.avisoft.info
----------------------------------------------
> On Mon, 10 Feb 2003, Dave Mellinger wrote:
>
> >
> > From: [EMAIL PROTECTED] (Raimund Specht)
> > Subject: Re: Ultrasound playback setup
> >
> > Recently, several relatively inexpensive sound cards supporting
playback
> > rates of up to 192 kHz (new DVD audio standard) appeared on the
market:
> >
> > Audiotrak Prodigy 192 : <a
> > href="http://www.audiotrak.net/eng/prodigy.html";
> > rel="nofollow">http://www.audiotrak.net/eng/prodigy.html</a>
> > SoundBlaster Audigy 2 : <a
> > href="http://www.soundblaster.com/products/audigy2";
> > rel="nofollow">http://www.soundblaster.com/products/audigy2</a>
> >
> > A suitable amplifier would be the TEAC A-H300 stereo amplifier. Its
frequency
> > range goes up to 80 kHz: <a href="http://www.teac.co.uk/teac/index.html";
> > rel="nofollow">http://www.teac.co.uk/teac/index.html</a> (go to
"AMPS"
> > and "Stereo Amplifier A-H300"). If you need a more compact and
portable
> > device, the Avisoft Bioacoustics ultrasound amplifier would be a
better
> > choice. That device is powered either by a 5 V or 12 ...36 V DC power
> > source and has an integrated over-modulation (clipping) indicator in
order
> > to prevent distortion. Detailed specifications will be available at
> > www.ultrasoundgate.com in a few days.
> >
> > An appropriate dynamic speaker that covers the frequency range from 1
to 70
> > kHz is also available from Avisoft Bioacoustics. It is compact
> > (80*120*65mm), rugged (aluminium housing and SPEAKON connector) and
can
> > produce high sound levels. In fact, the frequency range goes beyond 70
kHz,
> > but the sound levels at these frequencies will be lower. See also
> > <a href="http://www.ultrasoundgate.com/desktop.htm";
> > rel="nofollow">http://www.ultrasoundgate.com/desktop.htm</a>.
> >
> > Regards,
> > Raimund
> >
> > ----------------------------------------------
> > Raimund Specht
> > Hauptstr. 52
> > 13158 Berlin
> > Germany
> >
> > phone/fax : +49 30 9163758
> > [EMAIL PROTECTED]
> > www.avisoft.info
> > ----------------------------------------------
> >
> >
> >
> >
> >
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