USB mic not recording w/ surround speakers, faint without

[Robotech_Master]

I have a Logitech AK5370 USB mic, which I use for all my vocal apps. It works fine with most of them.

However, with Audacity, when I had my surround speakers plugged in (I use a motherboard with integrated RealTek HD sound) nothing I said into the microphone would get recorded by Audacity no matter whether I had set Audacity to record from sound mixer input or AK5370.

Now that I'm down visiting, away from my surround speakers and with only headphones plugged in, I thought to try again—and this time Audacity definitely records. But even with the input volume set to the max, the recording is rather faint; on the -1.0 to 0 to 1.0 scale of the Audacity display, I don't think it ever goes over 0.1.

What can I do to make it record louder (now) or at all (when the surround speakers are plugged in)?

[steve]

Some RealTek devices have an "auto-detect" feature, that is supposed to automatically detect what devices you have plugged in, and into which socket (microphones, main speakers, sub, etc.) Unfortunately, this feature can sometimes get it wrong and screw things up.

I'd suggest, as a test, that you try recording with NOTHING plugged into the audio sockets (no speakers or headphones).
If your microphone then works, then you have narrowed it down to troubleshooting the RealTek device.

[Robotech_Master]

I tried that, but it ended up being at about the same level still, even when I went into the RealTek settings panel and turned off echo suppression and noise reduction.

[steve]

With Audacity set to record from the AK5370, any RealTek setting should have NO effect on the recording.
IThe reason I asked you to try with nothing plugged into the RealTek inputs was to ensure that the RealTek audio device was not stealing back control of the recording input.

Have you tried recording with the Windows Sound Recorder? If you get the same problem there, then you need to be troubleshooting the mic rather than Audacity. Give it a go and post your results.
Good Luck

[Robotech_Master]

I'll give it a shot.

Just wondering: is there any way that Audacity might simply not be showing the true recording levels in its graphic display, that it might be "zoomed out" or something? Are there any options I should check to make sure?

[steve]

Yes, you can zoom in and out by clicking on the vertical scale. The maximum amplitude is from +1 to -1 (or 0 dB if you switch to the dB scale).

[Robotech_Master]

What's the "usual" scale? i.e. the scale at which a normal microphone recording should fill most of the space between the lines? I'm trying to figure out whether I'm actually recording faintly or it just looks like it the way I have Audacity set.

[Robotech_Master]

I have tried recording with an ordinary mic plugged into the back of my computer, in the HD Audio's in port. And the funny thing is, it only reaches about halfway up the bar too. When I did a spectrum analysis, it peaked at -14 decibels on the spectrum, and if I selected and clicked "Amplify" the default it displayed (the amount necessary to max the recording out) was 10.4.

But when I go to the volume control panel to adjust the levels, and select the HD Audio Input panel, the microphone volume slider is grayed out.

[steve]

It's not unusual to get less than 0 dB as the maximum signal from a microphone. With my cheap soundcard and mic the ansolute max I can get is -4.2 dB, and trying to push it any higher just clips (distorts) the audio. However -14 dB seems a bit low. Some soundcard drivers have a "tick box" next to the microphone record level setting that switches on an extra 20 dB boost to the signal.

[Robotech_Master]

There wasn't in this. And the microphone level slider is grayed out, even when I plug in a standard mic into the mic jack, let alone the USB mic.

(And I still need to test it, when I'm back home again, with my surround speaker set and see if it still won't record at all with that plugged in. For all I know it might have been something completely different keeping it from being picked up.)