PC weird sound

I'd check that it isn't a hardware issue with the headset first. Do you have a computer to plug the headset into and see if it also sounds weird? You can monitor your own input in the Sound options via Control Panel if you click on Properties of the
headset under the "Recording" tab, then click the "Listen" tab in the properties window and check "Listen to this device". See if it sounds weird on PC? That can help identify if it's the Xbox or controller.

You may need to use the optical audio out on your 360, yes, it has one, it's on the cable. Sometimes, there is an HDMI "off/on" setting in the menu of your TV or DVD player. Are all your settings set properly on your 360 and TV? If all else fails, use the
optical audio cable.

I do have it set to stereo uncompressed but will check again. Will report back this afternoon. the XBOX 360 passing through seems to have great sound all balanced.

ok,. i found the AV cable and have tested the xbox with a DVD in, and there is plenty of sound coming from it! no problem what-so-ever! i am gonna go and get a different HDMI cable at the weekend and try that too, just in case. i cant try the other HDMI
cable as it is nailed down on the skirting board otherwise i would. so i still dunno what it could be, i know it's not the TV as i have tried the HDMI in my neighbours blu-ray player and the cable is ok.

yeah no problem, will have to find the AV cable tho =]