🚀 go-pugleaf

The Altec Lancing acs-300 units have a built in DSP system in the
speakers...does, that help?
Stephen

Nicolas Alejandro Arauz writes
| Maybe someone can answer this question for me:
| > I had been thinking about trying to write an effects program like you
| > did in your archive, only using the SoundBlaster card, or the PAS-16 or
| > the new Gravis card.  It seems as if you obviously know something about
| > this, so I'll ask you.  My question that I wasn't sure about was whether
| > or not ANY of these cards would all simultaneous input/output from the
| > ADC/DAC do do digital effects?  Or perhaps even switch so fast that you
| > wouldn't notice a lag.  Have you done any work with the commercial
| > soundcards?  I haven't gotten your archive yet but I will take a look at
| > it now.  It seems like you're possibly using high-sample rate DACs/ADCs
| > from reading your message.  Thanks f or your help!

While working on the MultiMedia Extensions to Windows 3.0 and Windows 3.1 at  
Microsoft, I worked closely with the SoundBlaster card (but not the other two  
that you mentioned).  The Creative Labs hardware cannot support simultaneous  
digital I/O for various reasons, one of which is that they only allocate one  
DMA channel in the PC for transferring the data.  Even at 8-bits mono, the PC  
has trouble with one direction, and cannot support A/D and D/A with th  
SoundBlaster.  This is true for SoundBlaster card versions 1.5, 2.0 2.5 and  
3.0.

Perhaps someone else has experience with the PAS-16 or Gravis card.
-- 
Brian Willoughby	Software Design Engineer, BSEE NCSU
BrianW@SoundS.WA.com	Sound Signal Processing Software and Consulting
NeXTmail welcome	- NO EMAIL SOLICITATION without prior permission

Nicolas Alejandro Arauz (na0s+@andrew.cmu.edu) wrote:
: Maybe someone can answer this question for me:
: > this, so I'll ask you.  My question that I wasn't sure about was whether
: > or not ANY of these cards would all simultaneous input/output from the
: > ADC/DAC do do digital effects?  Or perhaps even switch so fast that you

I've had a go a doing a similar thing with my soundcard (for guitar effects,
etc). BTW, it's a SB pro version 1. I think it may be able to do
simultaneous ADC and DAC (not in DMA mode) but even if it does the audio
routing/mixing circuitry won't. For a start, you can't turn off the input
monitor without turning down everything else including the DAC, ie you
always get some of your original signal straight through (though I did think
about subtracting it). Also, selecting the DAC disconnects any sound from
the ADC (well, it gives random values - could be used as part of the ADC).

You can switch rapidly between ADC and DAC, but the result is pretty awful,
though it did work. After that I gave up, along with giving up on my
ultra-optimised 8 bit FIR fiter routines for the PC. I'll wait/pay for a
soundcard which is a bit less limited!

Antony. (deanaj@elec.canterbury.ac.nz) 

--=}>> On 4 Oct 92 03:50:37 GMT, deanaj@elec.canterbury.ac.nz (A. J. Dean) said:
> Nntp-Posting-Host: betelgeux.canterbury.ac.nz

> Nicolas Alejandro Arauz (na0s+@andrew.cmu.edu) wrote:
> : Maybe someone can answer this question for me:
> : > this, so I'll ask you.  My question that I wasn't sure about was whether
> : > or not ANY of these cards would all simultaneous input/output from the
> : > ADC/DAC do do digital effects?  Or perhaps even switch so fast that you

> I've had a go a doing a similar thing with my soundcard (for guitar
> effects, etc). BTW, it's a SB pro version 1. I think it may be able
> to do simultaneous ADC and DAC (not in DMA mode) but even if it does
> the audio routing/mixing circuitry won't. For a start, you can't
> turn off the input monitor without turning down everything else
> including the DAC, ie you always get some of your original signal
> straight through (though I did think about subtracting it).

Well, this is the case only for the Line and CD audio inputs.  It
seems that the microphone level can be reduced to silence, and it will
still record at normal volume.  It's as if the Mic level does not
adjust the input level, but just the "thru" level.

> Also, selecting the DAC disconnects any sound from the ADC (well, it
> gives random values - could be used as part of the ADC).

Yeah.. You have to turn "DAC Output" off before recording.  They don't
mention that in the Developers' Kit.  The worst part is that it can
take "up to 300 milliseconds"(!) to make the change.  This is probably
a misprint, as it happens much faster on my card.

> You can switch rapidly between ADC and DAC, but the result is pretty
> awful, though it did work. After that I gave up, along with giving
> up on my ultra-optimised 8 bit FIR fiter routines for the PC. I'll
> wait/pay for a soundcard which is a bit less limited!
> Antony. (deanaj@elec.canterbury.ac.nz) 

BTW, does anyone know of a lower-end PC soundcard that CAN do
simultaneous ADC/DAC?  Most of the common ones can't seem to.

-Steve

Steve Haehnichen
shaehnic@ucsd.edu

In article <39074@sdcc12.ucsd.edu> shaehnic@sdcc13.ucsd.edu (Steve - Happy Hacker!) writes:

   > Nicolas Alejandro Arauz (na0s+@andrew.cmu.edu) wrote:
   > : Maybe someone can answer this question for me:
   > : > this, so I'll ask you.  My question that I wasn't sure about was whether
   > : > or not ANY of these cards would all simultaneous input/output from the
   > : > ADC/DAC do do digital effects?  Or perhaps even switch so fast that you

   > You can switch rapidly between ADC and DAC, but the result is pretty
   > awful, though it did work. After that I gave up, along with giving
   > up on my ultra-optimised 8 bit FIR fiter routines for the PC. I'll
   > wait/pay for a soundcard which is a bit less limited!
   > Antony. (deanaj@elec.canterbury.ac.nz) 

   BTW, does anyone know of a lower-end PC soundcard that CAN do
   simultaneous ADC/DAC?  Most of the common ones can't seem to.

According to the soundcard roundup that Keyboard magazine did, there's a slew
of new cards coming out... if you have a little patience, you may find what
you want.  Personally, I'm waiting for the Ensoniq sound card that has 32
voices, 1 MB of voice ROM (I think?), and dual stereo (4-track) CD-quality
playback and recording for $349.

And the Ensoniq card is supposed to be able to do simultaneous playback and 
recording at that speed. 

I feel better about Ensoniq (a REAL synth maker with a rep for insane price/
performance value and good stuff) than Gravis (a joystick maker???), so in my
book Gravis loses on this buy.
--
_____________________________________________________________________________
| Michael Chen			| From the depths of our most lucid horrors |
|				| spring our fond hopes and pure desires... |
| mchen@groucho.cs.psu.edu	| except what comes from HELL! :-) 7/23/92  |
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