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Article #125

Re: How do I attach multiple speakers to a NeXT?

#125
From: Gordon Van Huizen
Date: Sat, 31 Oct 1992 02:32
56 lines
3270 bytes
In article <iacovou.720240851@leto> iacovou@leto.cs.umn.edu (Neophytos  
Iacovou) writes:
> 
>   Has anyone out in net-land found a way in which multiple speakers can
>   be attached to the NeXT? What I am looking for is this, I want to 
>   have N number of speakers on my NeXT. I'm not really picky as to what
>   hardware would be need to do this...or should I be? I also want to
>   access each speaker via a device, using standard 'C' functions such
>   as "write".
> 
>   Here is an example set up:
> 	1 Next
> 	5 speakers
> 	each speaker is accessed via its own device:
> 	   /dev/multi-audio1, /dev/multi-audio2, .........,  
/dev/multi-audio5
> 
> 
>   I know that in a way I am dreaming a bit here, but you must admit that
>   to the proper person this sounds like a do-able project. Anyone have
>   any leads on something like this that they can point me to?
> 

The only ways to do this that I can think of are:

1. Get an Ariel QuintProcessor (which has 4 more DSP ports on it). Attach  
two Ariel ProPort's (one to each of the first two Quint DSP ports). This  
will leave two DSP ports unused but hey - we're rich right?  Write some  
DSP code to load into the DSP's which will read a DMA stream and output it  
to the SSI (simple). Write a program that runs on the host that will  
perform the DMA to the DSP's with a method that gets invoked to fill each  
buffer (this will be a lot easier than setting up devices). Total cost:  
about $10,000 plus some work. You'll have two unused DSP's, one unused  
audio channel in one ProPort, and the most powerful digital audio  
workstation on your block.

2. Build a custom device that will attach to the DSP port and provide  
output to 5 DAC's. This will be a little messy. Write some code similar to  
that used in the above approach. Total cost: unknown. Probably under $1500  
in parts if you use OK-quality DAC's, but I could be wrong. The  
engineering costs are hard for me to estimate.

3. Connect a Dolby Pro-Logic surround sound decoder to the NeXT DAC's.  
Write some nifty DSP code that will generate surround sound encoding.  
Write a host program that ships 5 buffers at a time to the DSP. Use the  
LF, RF, LR, RR and CENTER signals for your 5 speakers. Total cost: depends  
on the decoder, you could pick up an OK one for under $500 (maybe even wih  
amps for the speakers). The DSP coding would be non-trivial...

Sorry for the bandwidth but it's Friday night...

-- 
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Gordon Van Huizen           vox: 619.488.9411  fax: 619.488.3045
Metrosoft                   gvh@metrosoft.com [NeXTmail welcome]
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From: gvh@metrosoft.com (Gordon Van Huizen)
Subject: Re: How do I attach multiple speakers to a NeXT?
Message-ID: <1992Oct31.023257.3314@metrosoft.com>
Sender: gvh@metrosoft.com
Reply-To: gvh@metrosoft.com (Gordon Van Huizen)
Organization: Metrosoft
References: <iacovou.720240851@leto>
Date: Sat, 31 Oct 1992 02:32:57 GMT
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