[linux-audio-user] sounblaster live platinum and full-duplex recording (noisy)

[Erik Steffl]

John Check wrote:
> On Monday 16 August 2004 02:33 am, Erik Steffl wrote:
...
>>   Line LiveDrive, Line LiveDrive Capture,
>>   Line2 LiveDrive 1, Line2 LiveDrive Capture 1
>>
>>   are all the way up, guitar pod (line6) is connected to two rca
>>connectors on the live drive. However I was recording mono only (in
>>audacity) so I guess only one of them was recorded.
>>
> 
> 
> OK my livedrive is a early revision and the RCA's are S/PDIF,
> but I use the 1/4" line/mic in. Set to line it's stereo
> Line-Livedrive (record ready - set to unity). It's associated capture
> fader is also set to unity. Capture (main) is record ready and at 0

> Things that cause distortion/phase cancellation/"howlround" (feedback with 
> british EQ ;):
> Bringing up the main capture fader unnecessarily
> Bringing up either of the AC97 faders

   ok, what's record ready, set to unity and capture main?

   the one called simply 'Capture' doesn't seem to effect recording

   'AC97 Capture' and 'AC97' do not have any effect either

   actually nothing does except of Line2 LiveDrive Capture 1 (Line2 
LiveDrive 1 controls how much I can hear but not the recording).

   No matter how I set those other ones the recording is same (recording 
is OK, overdubbing is really bad)

>>   when recording only (no playback at the same time) the recording is
>>OK, when I play click track at the same time the recording is very bad.
> 
> Where is the click routed?

   I wish I knew. How do I figure that out? Audacity has a device 
setting for both recording and playback, both of which only offer 
/dev/dsp. So I guess click (or whatever else I recorded first) goes to 
/dev/dsp.

>>   I was recording at 44kHz, thought that might be a problem so I
>>switched to 48kHz but then there's no full-duplex at all (i.e. the
>>already recorded stuff does not play when I record).

   ok, there is full-duplex with 48kHz, I just turned it off (but it 
sound just as bad as 44kHz).

>>   is this a problem of my setup or audacity? (I can't get muse working,
> 
> Well, something to keep in mind is when you add a track the output is summed,
> so you might have plenty of headroom until you add the click. 
> I've noticed a tendency for the SBLive sound to start sucking hard once it's 
> had a few transients bashed into the ceiling. I could be wrong as to the 
> particular case, but you should be knocking 3dB off of the source track level 
> for every track you add to account for the summing when you overdub.
> IOW 0dB to the master for 1 track, -3dB to master for 2 tracks, etc.
> 
> 
>>it hangs whenever (trace reveals it's reading from some pipe) I try to
>>save (which is required to create audio track)). Any other simple
>>recording programs (that would make it possible to play the previously
>>recorded audio (aka full-duplex aka overdubbing)?
> 
> Depends on what you call simple. If you were trying MusE, I'll suggest 
> Rosegarden4. I like Audacity, but the lack of metering really doesn't make it 
> suitable for recording. 

   anything I can get to work is simple:-)

   oh wow! just tried rosegarden4 (I tried the old rosegarden before but 
IIRC last time I tried the new one the debian package didn't work) and 
it works!!! It's somewhat confusing because I need to play first, while 
it's playing I can start recording and it records while playing and both 
tracks are OK! Plus it sometime complains about not being able to read 
data from disk fast enough but I guess I need realtime capabilities for 
that (jackd complains that my kernel does not have realtime capabilities).

   thanks for the suggestion,

	erik