Re: [LAU] Basic question about use of a lowlatency kernel

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To: Jeff Sandys <jpsandys@...>
Cc: <linux-audio-user@...>
Date: Tuesday, February 19, 2013 - 9:16 pm

On Tue, February 19, 2013 11:25 am, Jeff Sandys wrote:

> - Sound travels ~1 foot per millisecond, 8 feet from the speaker =

latency as listed by qjackctl (for example) is one way from the card's
buffer to jack. Double that by the time it gets back to the card. Cards
typically add 1ms each way. So with 64f/p at 48khz the one way latency is
2.67 + 1ms from the analog input. This is already pretty close to that
8ms... and I haven't done anything with the audio yet. Add eq, tube
emulation, box emulation, reverb, etc. and they all add more delay to the
signal.

This delay is more of a problem for live computer use than recording where
monitoring can happen outside the computer. Just to compare: if I put a
long enough cord on my bass so I can get 25 to 30 ft from my amp (to
adjust sound on the mixer) my timing is already having problems. This
would be about 50ft of sound travel, 25ft before I hear what the rest of
the band is doing plus 25 feet before I hear my own instrument. I can
notice the delay before I get to that 25feet by the way.

Now if I am just listening, I can be 100 feet away and it still sounds
fine... It is the interaction with that sound that shows up the latency,
the time from when I do something to when I hear it. A good reason to use
in ear monitoring on a large stage.

--
Len Ovens
www.OvenWerks.net

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Messages in current thread:
Re: [LAU] Basic question about use of a lowlatency kernel, Len Ovens, (Tue Feb 19, 9:16 pm)
Re: [LAU] Basic question about use of a lowlatency kernel, michael noble, (Wed Feb 20, 10:26 am)
Re: [LAU] Basic question about use of a lowlatency kernel, michael noble, (Wed Feb 20, 11:49 am)