[LAU] Are RT-patches needed anymore? (Was Re: >= 2.6.27 RT ETA?)

Lee Revell rlrevell at joe-job.com
Fri Jan 30 22:51:03 EST 2009


On Tue, Jan 27, 2009 at 10:05 AM, Jörn Nettingsmeier
<nettings at folkwang-hochschule.de> wrote:
> Svend-Erik Kjær Madsen wrote:
>> On tir, 2009-01-27 at 15:03 +0100, Cassiel wrote:
>>
>>> 5.3ms latencies: If you can't sense it... you don't need it
>>>
>>> r
>>
>>
>> Okay I allways learned that you should't be to proud to admit when your
>> wrong.
>>
>> I just ran a few test with a keyboard playing both the keyboard's
>> soundmodule and through midi and Qsynth, and I must admit that latency
>> was down to 1.3 ms before the audible time differece disapeard.
>
> to put things in perspective:
>
> the speed of sound in air is around 340m/s. that means that in one
> millisecond, the sound travels about 34 cm.
>
> anything under a few ms total systems latency will not be noticeable in
> a normal listening environment, because you don't stick your head into
> the speakers. a drummer hitting a crash cymbal will have 3ms latency
> before the sound reaches his/her ears.

In a situation where you can also hear the dry signal coming out of
the amp, I've found small differences to affect the sound.  5ms vs.
15ms is the difference between playing through a Marshall stack with
both cabinets right behind you and playing with one of them behind you
and the other 10 feet away.

You don't hear it as a delay like you would with 100ms, but you can
definitely hear it...

Lee



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