DVR sound issues

[Tay54]

I had FIOS installed a couple of weeks ago.   I have no problem with 3 of our STB's, but with the DVR I have a couple of problems with the sound.  

First, on recorded video the sound level is very low - have to crank the volume up very high just to listen. 

Second - when watching TV I get a distinct audible 'pop' every time I change channels.   I hear the pop occasionally when playing a recorded program also, like when the program ends.

I'm just running the sound through our TV speakers, no home theater etc.

Any ideas?

Thanks

BT