t46g sound quality problem vs t20

[asinshesq]

Hi, everyone. I have been running t20 phones on my local lan 3cx system (tied to my external pstn telephone service with a patton 4114 fxo gateway) for a few months. The sound quality from the handset (and via a plantronics 361n headset) has always been fine. A week ago I replaced the t20 with a t46g phone (and the 361N headset with a cs510 headset) and the sound is now awful. On the handset, the sound seems over-processed (it sounds robotic) with some cutouts that I never had with the t20. And the sound through headset is really bad (seems like the sound problems get exacerbated when I go via dect to the headset). I tried using the cs510 'wideband' setting and that was even worse. People I am talking to, however, report that I sound fine to them.

I am thinking there must be a setting I have screwed up (maybe in 3cx or maybe in the t46 settings?). For example, maybe I need to activate different codecs?

Anyone have a suggestion? The phone is pretty bad this way, and the phone/headset combo is almost unusable (well, I can use it but my wife can't ).

Thanks.

Alan