Need help with microphone feedback

ryboto · Post by **ryboto** » Sun Oct 12, 2008 7:16 pm

I've got a Plantronics USB headset. Ever since I changed boards to a P5Q-EM, my microphone has this repeating static interference. If I listen to the mic, I can hear it, sometimes it's loud, sometimes it's only audible if I speak into the mic. What component could be causing something like this?

ryboto · Post by **ryboto** » Sun Oct 12, 2008 7:52 pm

I should add a few things. It still happens even if I disconnect all other USB devices. Saturday I used it on and off all day, and my friend said he didn't hear the interference at all. I'm wondering if it's a bad ground, or interference from a fan or something...I guess I could try powering the fans from the power supply rather than the motherboard.

KyonCoraeL · Post by **KyonCoraeL** » Sun Oct 12, 2008 8:57 pm

in the realtek drivers there is an echo cancellation option in the speaker setup, maybe that is causing it.

ryboto · Post by **ryboto** » Mon Oct 13, 2008 5:21 am

KyonCoraeL wrote:in the realtek drivers there is an echo cancellation option in the speaker setup, maybe that is causing it.

This is a USB headset, it has it's own sound processor, it doesn't use the realtek audio codecs, or the audio chip onboard. I don't know if changing the realtek settings would help this, but I can try it when I'm home.

lm · Post by lm » Mon Oct 13, 2008 7:32 am

Is your usb device powered from a separate brick or from the mobo? Maybe the power is noisy and that noise is carried on to the analog audio path?

ryboto · Post by **ryboto** » Mon Oct 13, 2008 7:40 am

lm wrote:Is your usb device powered from a separate brick or from the mobo? Maybe the power is noisy and that noise is carried on to the analog audio path?

Like I said, the headset is USB, not analog, it gets a digital signal from the USB port. I've got the system on a power-conditioning surge protector. I've used the same headset with the same power supply/RAM/CPU/GPU with other motherboards(3 others) and never had this issue. The noise is only picked up on the MIC. The headset speakers sound perfect. The analog out is also not affected by this noise, my PC speakers are plugged into the analog out, and they playback sounds/video/music just fine, no interference or static.

kittle · Post by **kittle** » Mon Oct 13, 2008 10:28 am

ryboto wrote:This is a USB headset, it has it's own sound processor, it doesn't use the realtek audio codecs, or the audio chip onboard. I don't know if changing the realtek settings would help this, but I can try it when I'm home.

That very well could be the source of your problem. Since the headset doesnt go through your existing audio system, the settings and echo cancelliation and feedback canceliation wont be working like you are used to.

Also, dirty power or loose connections (anywhere in the PC) or just too much RFI could cause simmilar problems.
note also the dirty power could come from some component in your system and not from the wall -- it sounds like you have the wall power covered already.

ryboto · Post by **ryboto** » Mon Oct 13, 2008 11:10 am

kittle wrote:That very well could be the source of your problem. Since the headset doesnt go through your existing audio system, the settings and echo cancelliation and feedback canceliation wont be working like you are used to.

Also, dirty power or loose connections (anywhere in the PC) or just too much RFI could cause simmilar problems.

I still don't see how the recording settings for two different audio devices could intefere if one of them isn't even being used. I'll still adjust the setting, I just don't get it. I've never used the mic input on the realtek controller, I've only ever used the headset microphone.

As for dirty power, all of the connections are very tight, it's annoying to remove some of the molex connectors. The only component that has changed is the motherboard, so, something about this motherboard is causing increased electrical noise that's only having an effect on the mic input of my USB headset.

ryboto · Post by **ryboto** » Mon Oct 13, 2008 1:54 pm

Well, when I go to the recording device for the realtek, it doesn't really give me any options, since it detects that nothing is plugged in. I changed the effects for the stereo speakers so that all effects are disabled, but the static persists. Next I'll try putting the fans directly to the power supply.

ryboto · Post by **ryboto** » Mon Oct 13, 2008 2:11 pm

Here's a link to what it sounds like:
http://media.putfile.com/mic-testing-55

That's with the fans connected directly to the power supply. The clipping sound sometimes occurs on it's own, when I'm not even speaking, and it can be very loud.

bonestonne · Post by **bonestonne** » Mon Oct 13, 2008 3:30 pm

how is your audio set up? do you have any lines in? more importantly, is the microphone routed through your headset?

at the same time, how is the USB current on your motherboard? having multiple devices plugged in may be causing it to get electrical interference from something else. how's the back of your rig look anyway? if you have the cable crossing any AC power cables what you have is AC line noise, which is incredibly annoying and hard to clean up. only way around it is moving away from the AC source. luckily, computers use DC inside, so running wires isn't so much of a hassle. your power supply most likely wont cause it, but the power cable going into your computer could easily cause it.

working in a studio, that's the best i can think of. if its not that, then i'd say you've got one huge electrical interference problem.

ryboto · Post by **ryboto** » Mon Oct 13, 2008 4:01 pm

bonestonne wrote:how is your audio set up? do you have any lines in? more importantly, is the microphone routed through your headset?

My system has a realtek audio controller, a digital controller on the HD3870, and my Plantronics USB headset with it's own DSP(digital sound processor). When I plug the PLantronics in, I plug it into a front USB slot, which is in turn connected to a header on the motherboard. The Headset is self-contained, the DSP gets it's own driver, and has both input and output through USB, it does not rely on the Realtek in any shape or form, in fact, it shows up as it's own device in the sound manager.

bonestonne wrote: at the same time, how is the USB current on your motherboard? having multiple devices plugged in may be causing it to get electrical interference from something else. how's the back of your rig look anyway? if you have the cable crossing any AC power cables what you have is AC line noise, which is incredibly annoying and hard to clean up. only way around it is moving away from the AC source. luckily, computers use DC inside, so running wires isn't so much of a hassle. your power supply most likely wont cause it, but the power cable going into your computer could easily cause it.
working in a studio, that's the best i can think of. if its not that, then i'd say you've got one huge electrical interference problem.

USB current should be fine, I've only got two other USB powered devices on at any given time, but they're on a different controller. They've been the same two devices I've always used, they're wireless adapters for Logitech mice/keyboard.

The back of my system only has the incoming power for the system, DVI out, 4 USBs(2 keyboard/mous, 1 printer, 1 external HDD). Also in the back is a single 3.5mm out for my 2.1 speakers. I've unplugged all of these USB devices and still, the noise persists.

The power line going into my PC is actually a 12v DC line. I use a PicoPSU, the AC line is on the floor, next to a power brick, it doesn't come near the PC. No power wire crosses any of the back cables, it goes over them by a few inches, then down the back of my desk, whereas the other cables go to the left of my desk.

I think this is an internal issue, something about this motherboard is causing some sort of interference that wasn't there with the P5QL-EM(G43).

ryboto · Post by **ryboto** » Wed Oct 22, 2008 6:00 pm

I'm using a full size ATX power supply now, still, the exact same issue persists.

Cistron · Post by **Cistron** » Thu Oct 23, 2008 12:02 am

Does it make any difference if you deactivate the onboard sound via the BIOS? (Not that I have any electronical background or could tell why there is noise)

ryboto · Post by **ryboto** » Thu Oct 23, 2008 6:37 am

Cistron wrote:Does it make any difference if you deactivate the onboard sound via the BIOS? (Not that I have any electronical background or could tell why there is noise)

No, it does not. Last night, I may have fixed it. I went into the audio properties, and checked "allow programs to control this device", and "give exclusivity....." can't remember the rest of the second one. I also went into the headphone(not mic) properties and enabled "AGC", automatic gain control. After I did that, I tried to listen to the mic in VLC, but it wasn't picking up anything, i couldn't hear any output. So, I tried a skype call with a friend, and he said the noise is gone. Not sure what it means.