Output volume slider affects input level

[jehurd]

I searched the forum and do not see this addressed, so this post.

I am running Audacity 1.2.6 on XP. In trying to set up my input record source and levels I have run into this issue. While playing a CD on Windows Media Player and simultaneously recording it on Audacity, I have found that moving the output level slider (speaker icon slider) affects the input record level. Of course, moving the input slider (microphone icon slider) affects the record level also, but why is the output volume slider affecting the record level? No microphone or other input device is connected to the computer.

Also, moving Audacity's output level slider affects the desktop speaker volume even though I have not set the I/O for software playthrough.

I have changed the input and output sources in Audacity from the MS Sound Mapper to my Creative Sound Blaster PCI and back with no effect. Tried working thru all the volume controls, muting and unmuting, etc.

My XP sound and audio devices window shows the Creative PCI as the default audio device for input and output and no other device shows when I drop down the menu. Is this the problem, that Audacity is "stuck" using the Creative card? Is the PCI card somehow feeding speaker audio back into the record input?

I am assuming that if this was a an audio routing issue, then changing the audio input/output would have an effect, which it does not.

Any ideas? Thanks!

[kozikowski]

<<<I am assuming that if this was a an audio routing issue, then changing the audio input/output would have an effect, which it does not.>>>

You are almost certainly recording MIX-OUT or What-U-Hear as that's the only way you could get Audacity to record Windows Media. When you do that, both the playback and record side of your sound card are running at the same time. That's where the interaction comes in.

If you had a second computer recording the headphone output of the first one, none of this would be happening. That would be a simple playback on one computer and a simple record on the other. It's when you combine both on one computer that you get into trouble.

Koz

[jehurd]

Koz,

Thanks for the post.

That makes sense and would explain what is happening. I did not mention it in my original post, but I had tried recording (same set up) from WMP with Audacity's "Software Playthough" enabled. The output audio - how do I describe it - sounded like stuttering.

If I understand you correctly, that would put 3 audio input streams going to audacity: the output from WMP to audacity, my sound card playback output to Audacity and the Software Playthrough being looped back to Audacity. Since the 3 streams could not be exactly synced, it makes sense to me that the stuttering was caused by this when using Software Playthrough.

Did you discover this by your own testing? Do you know of a fix or workaround? I Googled high and low before posting the issue and did not find anything like this concerning WMP and Audacity. Any leads would be appreciated.

Thank you for posting!

Joe

[kozikowski]

<<<output from WMP to audacity>>>

Windows Media never plays to Audacity. It plays into the sound system which sends it out to the sound card. Mix-Out captures the sound card output buffer and sends it back into the computer as a record service. That's why not all sound cards have it. Anything else you do to the sound service is on top of that.

<<<Did you discover this by your own testing? Do you know of a fix or workaround?>>>

You could say that. I stopped using Windows®.

Koz

[jehurd]

Koz,

<<< I stopped using Windows®. >>>

I hear you on that. Heading to RHEL soon.

Thanks again for your help.

Joe.

[steve]

Heading to RHEL soon.

You may have trouble getting an up-to-date version of Audacity for RHEL unless you build Audacity from source - I think they are only up to version 1.3.0b.

[jehurd]

Thanks for the heads up, I had not checked on that. Really, Audacity is too good (for my simple purposes) to give up.

I could always keep the Windows box to run Audacity on and feed my audio into the sound card's aux in from the Linux box or other source by wire. I think that will avoid the issue I am now having.

But if Linux is like I hear, there is probably an equivalent audio processing application out there. Time to start looking.

[kozikowski]

Did I miss the part of the movie where Audacity will run correctly on all three computing platforms?

Koz

[steve]

But if Linux is like I hear, there is probably an equivalent audio processing application out there. Time to start looking.

Apologies if I gave the wrong impression. Audacity runs very well on Linux - I use it all the time.
RHEL is primarily designed as a server/desktop Linux platform for business, and as such they use applications that have been around for a long time and are thoroughly tested. The downside to this comes when you want to use a program that is rapidly developing as it can take some considerable time for the current version to become available in RHEL (unless you build it from source yourself). Also, applications like Audacity probably have a relatively low priority on this Linux distro. Ubuntu on the other hand runs much closer to leading edge of development. It is still sufficiently stable for normal domestic desktop work, but includes much more up-to-date packages. Unlike RHEL, Ubuntu do not stake their reputation on "enterprise level stability".