[Ekiga-list] Bad frequency response with Ekiga

[geo cherchetout <geo cherchetout laposte net>]

Hello,

Using Ekiga v.3.9.90 and the line input of his soundcard, and PCMA codec, 
Foo sends white noise to Bar who receives and records this sound with 
Linphone v.3.5.99.0. (Recent versions of Linphone make recording easy, the 
recorded sound being extracted from rtp streams, not from soundcard.)
Then, using Audacity, Bar displays the spectrum of the recorded sound. You 
can see it here: http://pix.toile-libre.org/?img=1367698438.png

Now, the same experiment is made with Foo and Bar using the same Linphone 
v.3.5.99.0 softphone, and the spectrum is much better as you can see there:
http://pix.toile-libre.org/?img=1367698567.png

Perhaps there is something like a wrong equation in Ekiga's or some 
library's code ? Or this is a feature and not a bug ?
I am able to compile Ekiga but not to modify the code by myself...