Hi I have an High Definition Audio chip on my laptop - which gives pretty decent sound for a laptop. (It uses Harman Kardon Speakers too which help somewhat).

In any case I have found that in Gentoo my sound totally sucks. It's really rattly, rasping and very crackly and broken up.

The exact same chip works really well on this same system with Debian - so it isn't anything to do with compatibility in Linux.

I know sound on most laptops isn't great - but mine is pretty OK, so it's not just a case of onboard sound not being very good - as the driver is clearly malfunctioning and the sound it is producing isn't normal at all.

Can anyone possible suggest a way I might be able to resolve this?

Thanks!

Have you tried lowering the PCM volume in your volume control software? You might need to lower the master volume control, as well. My system suffered from distortion due to saturation until I lowered these to about 75% of full scale. Change the volume control on your speaker to compensate.

No it still rattles and is horribly distorted - even at very low (indeed almost inaudible) volumes. Moreover as I said it works perfectly on exactly the same system on Debian Sid/Kanotix - which is currently installed on another partition.

Unfortunately there are reasons that are probably not very interesting right now why I have to have Gentoo installed - and while it is installed, I would very much like to get the sound working correctly.

As I said also, this is a case of the driver malfunctioning - it is very clearly functioning abnormally. It isn't simply that laptop sound isn' very good - it's definitely good enough under Debian (and Windows too for that matter) or that I have the PCM volume turned up too loud. I already had it set at 75% - as from experience this tends to be the setting that works best - and also again as I said the same identical settings work wonderfully on Debian.

First of all check if your Gentoo and Debian distro have similar alsa version.
Next - check the module loading parameters (/etc/modprobe.d or /etc/modules.d - look for files named with alsa and compare the contents).

If it won't help - post
head -5 /proc/asound/card0/codec#0
here - I will look around if I can help you.

My friend has the same board. He found support to be better with the most recent release of ALSA. Try updating that.