We have a Comrex DH22 Digital Hybrid. It worked fine for a while but we're now having problems. There are often problems with levels. Bring the level down - it sounds better on the air but the callers can't hear you, bring it up, it sounds like you're in a barrel. Sometimes when setting the level it may sound good on one call, and sound terrible on the next, especially cell phone calls. The Comrex seems to be a pretty good unit. Question is - do I send it off to the factory to see if they can do anything or do I start all over by purchasing another unit or brand?