See this post. First, I found that by switching to EVRC-B (from EVRC) under Vocode in the diagnostic menu, substantially increases speech quality. (only on the other end) Second, by changing the data rate from 153.6/9.6 to 153.6/153.6, allows for a more consistent connection speeds on the net. (edited, Thanks Mike84!) *edit* Looks like changing the data rate only affects tethering speeds atm, but not confirmed. To get to the Diagnostic menu, do the following: (Thanks to Neofite!) Dial ##PROGRAM, send, enter 000000, Verify Your mileage may vary.