Lee Revell wrote: > 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. thanks for the info, now I have to figure out how to use it:-) it looks like audacity uses oss (/dev/dsp) so I guess I could configure alsa so that /dev/dsp is hw:x,0 and e.g. /dev/dsp1 is hw:x,2 right now I'm not even at the point of caring for latency, for some reason the recording is of really bad quality when I use full-duplex (i.e. playback of click track and record), the quality is OK if I only record. erik
