On Fri, 2004-08-13 at 23:30, Erik Steffl wrote: > recording seems to be working OK but: > > in audacity when I record the track it sounds OK > > however if I generate click track and record then (the click track is > playing while I am recording) the recording is really bad (noisy, low > quality). > > I vaguely remember something about full-duplex on sounblaster not > being very good, i.e. there's something wrong when using it but don't > remember what (bitrate being forced to be very low or something along > those lines). > > However I can't find any information on that subject now (I tried > google and creative site), does anybody know details and/or have some > pointers to relevant docs? > > system: debian unstable, 2.6.5 kenrel (with alsa), sounblaster live > platinum (with live drive). > The hw:x,0 capture device on the sb live is not very good. For good results you have to use the hw:x,0 playback device and the hw:x,2 capture device. You have to use 48khz. To record at the lowest latencies you have to record more than 2 channels. This is because the capture buffer size is fixed in bytes; doubling the number of channels halves the amount of time between interrupts with a fixed buffer size. This did not work at all until very recently, I believe you need the ALSA 1.0.6-rc1 release candidate. Search the recent alsa-devel archives for 'emu10k1 low latency capture' and 'emu10k1 multichannel' for more info. Lee
