[LAU] audio latency question

[andy baxter]

> Hi,
>
> I am thinking about a possible design for the second version of the 
> position sensing drum pad I have been working on, and I have a 
> question about latency. I am working around the assumption that 10ms 
> latency is about the worst it can get before people start to notice it 
> in practice, so I am thinking of building the pad in a way where the 
> normal latency is about 1ms, but it degrades to between 10-15 ms in 
> the very worst case (many simultaneous strikes and pressure variations 
> across the pad). Allowing this level of degradation would make it 
> possible (I think) to use an arduino rather than a faster processor, 
> which would be nice.
>
> So the question is, where does this 10ms figure come from, and is it a 
> reasonable working value? I have picked it up somewhere but I'm not 
> exactly sure where.

Another question on this topic - once a synth is triggered (e.g. in 
supercollider which I'm using at the moment) is the latency from that 
point just the jack latency, or is there an additional latency that 
comes with the synth?

Also, could anyone give me a rough idea of what level of latency and 
jitter to expect when using alsa midi ports to send data between two 
applications?

I'm having another look at my first version of the pad, and I'm trying 
to get the latency as low as possible before I present it at LAC in May.

andy