Subject: [Fwd: [linux-audio-dev] analog latency]
From: Jörn Nettingsmeier (nettings_AT_folkwang.uni-essen.de)
Date: Mon Jun 12 2000 - 18:23:13 EEST
again, you almost missed my smart-ass comments due to the blasted
reply-to: setting !
here it goes:
Jörn Nettingsmeier wrote:
>
> Paul Barton-Davis wrote:
> >
> > just a quick little FYI:
> >
> > i was reading the "manual" that came with some new Tannoy monitors I
> > got a few weeks ago. there is a comment in the back to the effect
> > that:
> >
> > * the filters on almost every analog EQ have a delay time of
> > 25usec
>
> this delay depends very much on the frequency, but let's assume this
> is not so.
> now worst case is probably the 31-band graphic eq with additional
> shelving attenuators:
> (31 + 2) * 25usec = 825 usec or .83 msec
> calling this "latency" is a bit nit-picking, if you compare it to
> the sound travelling latency of about 6.1 msec given a distance to
> the monitors of only 2 meters.
>
> but then again, you are principally right.
> stick your head to the membranes and, for a true
> just-in-time-experience, remember to keep your cables short. each
> meter will introduce another 3.3 nsec latency :-D
>
> the only considerable latency in the analog domain is the time a
> tape takes to run from the record to the playback head, which is why
> monitoring is done via the record head.
>
> and of course these minimal latencies you mentioned become important
> when speakers must be phase-aligned (which is probably why tannoy
> mentions it in the manual).
>
> regards,
>
> jörn
>
> > * with only a few exceptions, all equalizers run the filters
> > in series.
> >
> > So much for the naive belief that analog systems have no latency.
> >
> > OK, not much :)
> >
> > --p
-- Jörn Nettingsmeier Kurfürstenstr. 49 45138 Essen, Germany http://www.folkwang.uni-essen.de/~nettings/
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