Re: Burroughs, Strobes (was Re: monitor refresh rates & epilepsy)


Subject: Re: Burroughs, Strobes (was Re: monitor refresh rates & epilepsy)
From: jan.larsson (jlarsson@quartet.se)
Date: Tue Jan 18 2005 - 00:57:31 EST


If you like UV22 then try the POW-r noise shaper many systems provide,
it sounds even better,

It sounds like you are talking about the ProTools TDM mixer-plugins. If
you mix more than 68 channels then more than one DSP-chip is required
and they used to truncate the communications between the multiple
DSP-chips (each rnning an instance of the mixer-plugin) to 24-bits.
3-4 years back they fixed this not by dithering but keeping the full
48/56-bit mixer resolution.

ProTools TDM has a 24-bit path and a 48/56-bit mixer. If you use their
dithering mixer and use plugins that work at 48-bit and dithers to
24-bit correctly (like the Sony Oxford series) then it is one of the
cleanest setups around today. I also like the fact that they openly
declare how their systems are designed, most manufacturers will not
tell you anything.

Note that ProTools LE (non-TDM-hardware) use 32-bit floating point like
everyone else (it seems) that rely on the native CPU in the computer to
crunch numbers. 32-bit floating point has a 24-bit path. Due to the
limitations in CPU-power many "native" digital workstations dont dither
at all places required. Instead they rely on the rounding errors of
floating point math to mask the truncation.

This is all a real mess.

2005-01-18 kl. 04.53 skrev Richard Wentk:

> It's probably worth mentioning that the latest Cubase SX3 with 32-bit
> internal resolution and Apogee's old UV22HR dither on the output stage
> sounds extremely smooth. I've never been a Cubase fan, but for various
> reasons this version has made me change my mind.
>
> And also that I was talking to one of the technical people at Meridian
> recently (the hifi people, and owners of the MLP encoder technology
> used in DVD-A) and he mentioned in passing that a certain well known
> pro-audio system had only recently worked out how to do dither
> properly across multiple plug-ins. And without that it sounded - to be
> polite - less capable than it should have.



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