Issues using the PAC line lever controller to control my tower speaker volume

Okay i have been beating my head against a wall here on this issue. I have the following setup

Kenwood Deck with three amplifier preout channels (Front, Rear, Sub)

1 Four channel rockford fosgate amp with the rear channels going to the boat speakers and the front channels going to the tower speakers

1 amp for my subs

I have a line lever volume controller going from the deck (front channel rca pre out --> line level controller --> front rca input on the amp)

Here is my issue, when I turn the volume up on the PAC unit it lowers the volume of my subs. It's almost as if the extra signal going to my first amp is lowering the signal going to my second amp.

Anyone know how the hell to fix this? Do I need to buy an EQ?

Sounds like you have some RCAs connected in the wrong spots. if you are making use of the front, rear and sub pre-outs, then its plug and play to put the PAC inline on the RCAs supplying the tower side of the tower speakers.

I've gone over the rca cables numerous times and they are connected properly. I even tried running the second amp using the passthrough rca cables from the first amp. That is why I am so stumped on this. Maybe my deck is bad?

Well, two things stand out. 1) turning up the dial, turns down the volume. 2) its lowering the sub level on a a completely different amp. Once the audio signal leaves the head unit, on their own RCA, there is nothing in common between the two.

Are you using three 2 chnl RCAs or single 6 chnl or a 2 and a 4 chnl RCA? The issue lies in the RCAs

I am using three separate 2 channel rca cables. I know it doesn't make sense that is why I posted this thread. I wonder if there is something wrong with my deck or maybe the built in LPF/HPF crossover

The deck is upstream of your issue. Take the line level knob out of the loop and see is all 3 zones play. Then disconnect each pair of RCA 1 at a time and see if the corresponding zone stops playing and only that zone. Just power down to dis and re connect.

All three zones play now. It's just that the sub woofer channel volume drops by about 40% when i use the line level knob to increase the tower speaker volume.

I promise you that the RCA's are connected properly.

Not disputing they play, looking to see that if you have the front RCA disconnected, to the in-boats stop playing, rear rca disconnected tower stop and woofer disconnected and woofer stops. And through this, no other zone stops playing. Its a process of elimination. Prove what works and you are left with whats broke.