Re: [LAU] Audio interface latency measurements

On Sat, 21 Jun 2014, Robert Jonsson wrote: Measure round trip. That is the only way to find out. As an aside, if you have to measure it, does it matter? In general, the manufacturers seem to have chosen to use the extra through put on USB2 to add extra bit depth (24bit instead of 16), extra bitrate (96k or more instead of 48k) and more channels. The latency would end up being simmilar. Being realistic... I can set my card to ~.6ms (one way) latency at 48k... maybe less at 96k but I haven't tried it. However, The dsp inside the audio interface itself already adds ~1ms of latency. That is 1.6ms one way. I can double the latency in jack to 1.2ms and the total is now 2.2ms not that much higher(this is not measured values BTW so the jackd added latency may be even less of the equation). There is a point where the latency of the interface itself is the main part of things... and how many inches away or towards the speaker do I have to move my head to have the same effect? When is a latency decrease really a gain? It seems to me from my own experience that a USB1 IF at 64/2 is good enough for live work as an effects rack or softsynth. For tighter needs the cost for the interface and the computer to run it goes up. Even audio imaging with multi speakers using delays for spacial placement is not overly latency dependant so long as all the channels are in good sync. -- Len Ovens www.ovenwerks.net