There's a lot of places the audio levels get set, and any one of them can cause low dispatch audio. It can be at the console's BIM card, a microwave channel, a voter, or a control station.Any reason for this?
Unlikely. If that was the issue all the traffic would sound low. I'd agree with the others, somewhere in their audio chain from their ECC to the repeater they've got a level issue. Many places that it could be. Likely the guys in the field are just accustomed to it and have cranked up their volume.Maybe receive set for wide band and they are now transmitting on narrow???