Re: [LAU] FOSS Ethernet Soundcard

From: <fons@email-addr-hidden>
Date: Tue Nov 24 2009 - 12:20:05 EET

On Tue, Nov 24, 2009 at 10:15:05AM +0100, Florian Faber wrote:

> >> So I will plug this into my ethernet and have < 1ms latency? :)
> > Given the fact that AD/DA converters introduce more then one ms latency(*)
> > already: No.
>
> That depends on the converter and the sample frequency. Fast converters
> can go as low as 5 samples conversion latency.

It's not the AD/DA conversion that introduces most of the delay.
At 44.1 or 48 kHz the antialiasing filters are the main cause
of delay. A linear phase filter with a transition band of 1khz
(e.g. unity gain up to 21 kHz and near zero at 22 kHz) must
have a delay of around 1/1kHz or 1 ms.

Short delays are possible at 96 kHz, where you can have full gain
up to say 28 kHz going down to zero at 48 kHz. That's a range of
20 kHz, corresponding to 0.05 ms. It's one of the few advantages
of higher sample rates (but only if you don't use the full band-
width).

Ciao,

-- 
FA
Io lo dico sempre: l'Italia č troppo stretta e lunga.
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Received on Tue Nov 24 16:15:01 2009

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