Harman Kardon AVR 220 - sub output only on certain surround settings
 

been using this receiver for about 4 years without a sub, but last week
i finally picked up a powered subwoofer for it. Connected using the SUB
OUT on the receiver with standard RCA connection.

for some reason, I don't get any output at the subwoofer when the
surround setting is on "no surround" anything "Dolby" - (Dolby Digital
5.1, Dolby Pro-Logic II, Dolby 3-channel). I HAVE subwoofer output with
hall, theater, 5 ch stereo, vmax, and logic7.

All is true using inputs from: 2-ch analog (CD player) , 5.1 channel
optical (Xbox playing DVD) , 2 channel PCM optical (Xbox playing CD).
The only thing I haven't tested is DTS, because I can't seem to find a
DVD with DTS anymore.

I do have some electronics knowledge, so if anyone has any advice to
fix my output problem, I'd gladly appreciate it.

Jon