Cockpit speakers & sub not working / Clarion apx480m settings?

[factive]

Clarion XMD3

Fade & Balance are centered. Amp now has all the correct settings in place and I tried moving the RCA cables to the other ports and that didn't work.

I think at this point I'm about ready to just buy a new amp

[a0128]

Looking at the Clarion manual it appears that unit has a separate subwoofer control. Have you verified that the sub volume from the head unit is adjusted correctly?