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

From: Len Ovens <len@email-addr-hidden>
Date: Wed Feb 20 2013 - 10:01:20 EET

On Tue, February 19, 2013 11:39 pm, Tim Goetze wrote:
> [Len Ovens]
>>On Tue, February 19, 2013 11:25 am, Jeff Sandys wrote:
>>> - Sound travels ~1 foot per millisecond, 8 feet from the speaker =
>>> 8ms latency
>>
>>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.
>
> If they're well-engineered, latency from the digital effects listed
> will amount to well under half a millisecond.

While I don't doubt the calculations could be done in that time, I assumed
they would still have to use the same size buffering as jack, so even if
it was all done internal to one effect there would still be at least
2.67ms in the example above. 2.6ms each if they each hit jack in between.
TBH, I have used my netbook as a guitar effect with 128f/p and no
noticable delay.

-- 
Len Ovens
www.OvenWerks.net
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-user
Received on Wed Feb 20 12:15:04 2013

This archive was generated by hypermail 2.1.8 : Wed Feb 20 2013 - 12:15:05 EET