LCQ 1 intermittent output on sub channel only

I'm running the audio control lcq1 in my 2006 mega cab and I'm having issues with the sub volume dropping to about half and coming back to full intermittently. I have tried to change the summing jumpers to every possible combination, checked amp grounds, tried different amps all with the same result. I can use a cheap loc and have zero issues with the sub volume changing. The channels that go to the subs is the only one doimg this. Does anyone have any ideas I can try to clear up this issue?? Any help is greatly appreciated. System details are listed below...

Infinity sound system with factory nav/6 disc
Audio control LCQ 1 with acr2 knob
Jl audio xd600.6 on mids/highs
Jl audio xd600.1 (x2) on subs (2 ohm load each)
4 jl audio 10w3's

 

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