[LAU] DC offset

[Rustom Mody]

On Sun, Jan 29, 2012 at 11:11 PM, Fons Adriaensen <fons at 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
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