Low volume Shaker 1000 trunk subs

Hey guys,
Anyone heard of this one before? My subs in my trunk are working, but the
volume is very low, bass inside car is fine. Fuses 6, 9 (under hood) and 20
(kick panel) are all good, I couldn't find any others related. Yes, Shaker
option is on in the deck. I've even reseated all the connectors. Everything
inside is working fine, it seems isolated to just the trunk. Suggestions or
ideas on troubelshooting this? I could see loosing an amp, but both at the
same time, hmmm.
Thanks all,
-Brian