Help with PD installation?

[newdendrite]

Could someone give me a lead on how to correct a problem with a laptop installation of PD?

Everything went smoothly initial installation, but audio output from the laptop sound hardware has a periodic glitch somewhere between 1 and 2 Hz in frequency -- kind of a click. The amplitude of the glitch varies with the software volume control, so it doesn't seem to be clipping. When I run other applications such as Firefox, the frequency of the glitch will change with when I change the web page, but it's still there when all other applications are shut down.

The laptop is a Thinkpad T60 running a dual core Intel processor under XP Pro. I tried giving PD real time priority and assigning it to one core, but no joy.

I would guess this is some process interrupting the sound driver, but there are are many process running on the laptop. Does anyone have a guess where I should start looking for processes to eliminate?

Any guidance (or even reasonable guesses) would be appreciated.

Thanks,
Michael

[EdisonRex]

Hi, and welcome to electro-music.com!

It sounds like you are having buffer underruns. I'm not familiar with the T-60's sound control panel, but if it's a Soundmax device or some other ESS device, stock XP only gives you a few options. Try looking in the advanced audio properties, there should be a panel where you can adjust hardware accelleration (try turning it down), or sample rate conversion quality (try turning it down)... If you do find a buffers setting in one of the control panels for your sound driver, try adding buffers, if the problem gets worse, then subtract buffers. It's an inexact science, only because hardware and operating systems are all so different.