On Sun, Jan 29, 2012 at 11:11 PM, Fons Adriaensen <fons@linuxaudio.org> wrote:

On Sun, Jan 29, 2012 at 10:43:48PM +0530, Rustom Mody wrote:

> Thanks to Al Thomson pointer to look at 'normalize' I have found that my
> equipment (just a vanilla sound card) has/introduces some DC offset.
> How to remove it? Why does it come?

How much is 'some' ? Capture or playback ?

Immediate context:
Im trying to capture from firefox using the .asoundrc/jack settings shown
http://jackaudio.org/routing_alsa
[Track is http://www.raaga.com/play/?id=183659
I would just buy it if it were for sale; its not. You may have to click past an ad]

However Ive noticed earlier that when I use my (cheap headset) mike to record directly into audacity, this similar DC offset occurs. Since I am no audio pro I did not know what to google for before seeing the tabs in the normalize dialog of audacity.

So if you ask me exactly how much DC offset I dont know how to find out in figures. The audacity track shows it 1/4th to 1/3rd way up. Center is 0.0 top is 1.0 inbetween is 0.5.
This is little more than half way between 0 and 0.5.

When I run the audacity normalize tool a certain booming sound is there which is not in the original. So if there is some way of capturing without the offset