On Tue, 15 Apr 2014, david wrote:
Interesting. What is the difference between speed of sound in air and the speed of electricity through a cable?
I was talking about through air. I can only play as fast as I can hear and at thirty feet or so from the sound source, my instrument sounds delayed from the rest of the band because I hear their sound that much later and play my part that much later. I don't normally play at that distance, but ten feet is pretty standard.
I think the lowest I've had my UCA-202 (USB 1.1) card work at was around ~3msec latency (on a USB2 port) with a Debian RT kernel just fooling around (no other RT optimizations on this 2.4GHz i7 laptop). I've had Yoshimi problems when latency gets too low on my stock kernel. And when I first tried Zyn, it had problems at much higher latencies than Yoshimi did at the time.
Is that measured round trip? Or one way through the jack part? What sample rate? (I'm using 48k) I can get qjackctl so it says I have .6ms latency. But I think that is one way, 1.2ms ... then add ~1 ms each way just to get through the sound card monitor mixing and maybe a bit more and I have already three and a half ms. Then I am some distance away from my monitor too. Perhaps with a newer faster CPU I could run at 96k and work with a FW device and get the same results. USB is very handy for many things but for sound it takes some playing around to get a clean low latency set up.
However, it looks like I can still get lots of MB with PCI slots in them. I will probaly do that. Hopefully with three PCI slots I can get one that is irq clean.
-- Len Ovens www.ovenwerks.net _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
