[comp.sys.next] Wondering abou DSP capabilities...

jtn@potomac.ads.com (John T. Nelson) (03/09/89)

I'm wondering about the capabilities of the DSP chip on the NeXT
machine.  Will I be able to process say 8 channels of digital data at
once in the digital domain and output them at the 44.1 Khz rate?

Let's get specific: I'd like to have the 68030 interpret incoming MIDI
data and for each note or MIDI command, process say 2 seconds worth of
a looped sample stored in the NeXT's memory.  Each sample would
obviously contain 88.2 individual data items.  Alterations to
each sample could be extensive (filtration, envelope mods, pitch
transposition within say an octave range) as well as in-digital mixing
of all samples (modifying their amplitudes, EQ, etc).

All this would then be output through the DAC.  That sounds like a lot
of work for one DSP with 600 instructions per individual PCM data
sample.

I'm also wondering about the DACs and any filters used on the NeXT.
There's lots of technical data on the DSP but I haven't heard anything
about the specifics of the DACS (16 bit linear?) or filters (brick-
wall, digital, analog?).  These will affect sound quality as well.

Does anyone know anything about the music kit that comes with the
NeXT?

Clearly I would like to use the NeXT as a sample player and perform
everything in the digital domain (I don't mind writing software) for
the highest quality sound possible.  Problem is I don't really know
what is possible with this machine sigh.



John T. Nelson			UUCP: sun!sundc!potomac!jtn
Advanced Decision Systems	Internet:  jtn@potomac.ads.com
1500 Wilson Blvd #512; Arlington, VA 22209-2401		(703) 243-1611

"I have no idea why I've started liking rock music well after my teens,
but I do have a theory about why older people largely stop listening to
music much.  They can't hear it."