yes, power is also source of background noise, but not all the time. you must also have proper grounding.
with pc-phone, it could also be related to your phone/speaker gain controls. so u have to be definite on what kind of background noise u are getting. best codec for sip? it's always best to have alaw or ulaw. :) but bw-consuming. alaw is if u are using E1s. ulaw for T1s. don't even bother to use gsm. better get g729. some says u can use g723.1 with * w/o add'l purchase of license or something.. but i couldn't make this codec work. (so i went for g729.. :) ) im testing its quality though as digium cards are using CPUs as DSPs. ----- Original Message ----- From: "Jonathan Biggs" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, January 22, 2004 11:01 AM Subject: Re: [Asterisk-Users] Background Noise > Just to add some info from recent experience. May > help, > May not 1 X100P 2 X 4 port TDM400P > > Had to hook a dial-in palm PDA base for a custom > software implementation to my * system and have the > modem dial out and work properly. Phone connects to > second port on PDA Base > > Experienced very bad "electrical" type noise on the > line, hum, buzz, fad in and out. would come and go. > > Switched ports, wires, rxgain and txgain changes, > phone changes, nothing helped > > the PDA base is also connected via serial port (or USB > did not matter) to desktop computer for sync purposes > > Through trial and error. Found noise coming from > connection to desk top computer. On, Off did not > matter. > > Resolution. The power strip surge protector I was > using on the desktop computer has two modes for noise > filtration built in. 75 Hertz (or something, don;t > remember) and 50 Hertz. I moved the plug for the > desktop from the 75 side to the 50 side, All noise on > line now gone. > > Not sure if this helps, constant noise on all sides > may be power and noise filtration related... > > > > > > --- "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> > wrote: > > Hi All > > i have some background noise problem with * and a > > diva srv 4bri + chan_capi 0.3.0 + X-Ten PRO on my > > pc. > > Both in incoming and outgoing call have a background > > noise. > > > > there is some tuning to do? > > where can i find documentation about capi.conf? > > which is the best codec for sip (ulaw, alaw, > > gsm...)? > > > > mark > > > > _______________________________________________ > > Asterisk-Users mailing list > > [EMAIL PROTECTED] > > > http://lists.digium.com/mailman/listinfo/asterisk-users > > To UNSUBSCRIBE or update options visit: > > > http://lists.digium.com/mailman/listinfo/asterisk-users > > > __________________________________ > Do you Yahoo!? > Yahoo! SiteBuilder - Free web site building tool. Try it! > http://webhosting.yahoo.com/ps/sb/ > _______________________________________________ > Asterisk-Users mailing list > [EMAIL PROTECTED] > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
