Software playthrough unchecked causes slow playback

[plebsy]

Whilst trying to overdub some tracks I've run into a problem with Audacity 1.3.7. If I have software playthrough checked, recording works fine, except there is the unavoidable lag. To avoid, this I monitor the sound of the instrument I'm currently playing live through speakers or amp, and overdub that onto an existing set of tracks that I listen to via another set of speakers. Now, this would work fine except that if I uncheck software playthrough, audacity slows to something like 1/10 of the recording/playback speed. Is this a known bug or is there a way around this unfortunate feature?

Setup:
Windows Vista Home
Dual Core 2.8Ghz, 2GB
Presonus Inspire 1394 acting as a mixer (recording and lag free monitoring)
Soundblaster SB X-Fi (playback)
Audacity 1.3.7

Edit: I do not encounter this problem on 1.2.6

[steve]

This is not, as far as I know, a known issue. I suspect that somewhere along the line the Presonus and the XFi are not playing nicely together - possibly not agreeing on what the sample rate is.

Can you try it, first using the X-Fi for recording and playback, then with the Presonus for recording and playback.
Test at different sample rates and let us know the results.

[plebsy]

Sure thing. Here's what I did:

Edit -> Preferences -> Audio IO -> Two check boxes, 1. overdub and 2. software playthrough. 0 = unchecked, X = checked

8kHz Sampling rate:
Testing with SB XFi as Input and Output:
00 => Slow
01 => Fine
10 => Slow
11 => Fine

Testing with prosunus as Input and Output:
00 => Slow
01 => Fine
10 => Slow
11 => Fine

Same pattern at 44.1kHz.

[steve]

How very strange.

Try this:

1) Close Audacity

2) Open "audacity.cfg" in Notepad
You will find the file in: Users<user name>AppDataRoamingAudacity
It is a hidden file, so you will need to enable hidden files.

3) Delete everything from the file except for the line: "NewPrefsInitialized=1"

4) Save the file (make sure that Windows does not add ".txt" to the file name.

5) Completely disconnect the Presonus from your computer and reboot.

6) Open Audacity - set the default sample rate to 48000 Hz (software playthrough will be off by default - leave it off)

7) Record something and play it back.

[plebsy]

OK, done as instructed.

Microsoft Sound Mapper: works fine with software playthrough unchecked.
SB XFi: works fine.
Inspire Prosunus: works fine.

I guess I must have set something incorrectly when fiddling around, though I don't know what. Well, it seems to have solved it so many thanks for taking the time to sort this out!