Mic looping sound badly

[Katzhuu]

Hi,

I can't get my mic to work on my new comp. I have Asus P5B Deluxe WiFi/AP motherboard with onboard audio.

Here are my sound settings.



For those few words in finnish there, here are the translations:
MAIN WINDOW
Soita = Play
Tallenna = Record

SIDE WINDOWS
Muut säätimet = Other controls
Etupaneelin mikrofoni = Frontpanel microphone
Sulje = Close

If the Microphone boost is OFF, nothing happens. (It does pick up something, but only if I yell my heart out.)

If the Microphoneboost is ON, sounds start to loop. A short whistle just keeps repeating louder and louder. Also there are pretty bad distortion on it.

Any suggestion what might be wrong?

 

[mkaibear]

What sort of microphone is it?

 

[Katzhuu]

What sort of microphone is it?

Creative headset HS-300 with mic. It works fine with my other computer.

 

[Katzhuu]

So to clarify it more: I am using a headset, so the sound is not looping through the microphone itself. It is somehow looping inside the computer/software.

 

[sailer]

Ny chance, do you have both onboard sound and a soundcard installed?

 

[Katzhuu]

Only onboard sound.

Probably I've just got some switch/checkbox on wrong setting, I just don't have any clue which one...