GMod and source games voice lag

Hi there, for a while now, voice chat has been very laggy for me, unable to make out what anyones saying (extremely broken up) the gameplay is fine, no lag with that but the voice chat is a problem, it used to work fine, we recently got a new router (not sure if it started when we got it) but yeah, any ideas why it happens?

not sure what other information you need, the new router is a speedtouch netgear one (or something like that) we have relatively fast net

Thought i would bump this since i never got an answer