[Asterisk-Users] Asterisk Voice Problems

[Shyam Gopale]

Hi, 

I am running Asterisk 1.2.1 using Digium TDM 400P with 4FXO lines 
to connect to the PSTN world. But, I constantly get clipped voice whenever 
there is a call placed using Zap channels. 
I have tried it all the recommended solutions 
- turned off all non essential services on the machine 
- ran fxotune 
- Changed IRQ settings
But nothing works. 
The only thing that works is reducing the rxgain to around -20. But 
this leads to other issues like the hangup on the PSTN line is not detected 
by Asterisk. 
Anyone have a clue about how to fix the bad quality problem. Any 
help will be highly appreciated. 

Thanks, 
Shyam