Newsgroups: comp.sys.next
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From: smb@data.com (Steven M. Boker)
Subject: Re: Controlling volume of audio presentations
Message-ID: <1991May14.045753.19092@data.com>
Organization: Data Transforms, Inc.
References: <5091@dirac.physics.purdue.edu> <1991May14.002110.27936@milton.u.washington.edu>
Date: Tue, 14 May 1991 04:57:53 GMT

In article <1991May14.002110.27936@milton.u.washington.edu> wiml@milton.u.washington.edu (William Lewis) writes:
>In article <5091@dirac.physics.purdue.edu> murphy@gibbs.physics.purdue.edu (William J. Murphy) writes:
>>So, how fine of a control can be achieved with the NeXT's volume control?
>
>  The volume is an integer from zero to 43. The 0.0 to 1.0 value passed
>to other routines gets mapped into this range. I'm not at all sure
>what sort of relation this 0-to-43 has to, say, decibels. I think you
>can set the volume (right & left) directly using one of the SND*()
>calls -- SNDSetVolume(), probably.
>
I think that you have a little more control than just the volume setting.
By using the DSP you can have 16 bit interpolation between those 43 volume
settings.  Of course there is, no doubt, some overlap.  Has anyone stuck
a scope on the line outs and calibrated the output?  Seems like it would
be a fairly simple task to get a linear or log scaling set up.

Steve

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 #  Steve Boker           #             "Two's bifurcation                  #
 #  smb@data.com          #             but three's chaotic"                #
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