Subwoofer power level impacted by HU volume

Hello all!

Wondering if anyone has any advice or help with an issue I'm having with my subwoofer set up.



I have a 07' charger rt with the premium Boston acoustics speaker set up. I decided not to change the stock HU to save some money and it works just fine. I wanted some extra bass so I hooked up my 2 15" kicker subs to a JX 500/1 mono amp with an extra audio battery inline with the power connections.



Due to the HU being stock, there isn't any RCA outputs from the deck. And my amp unfortuately has no high level input. So I spliced into the the rear speaker wires and put a high level - low level converter to convert it to the needed RCA connections.



The subs work great and hit quite hard at lower volume on my HU. But when I begin to turn the volume up, the subs seem to become less powerful as the volume increases. The still hit, but at a knowticably less power level.



Anyone have any ideas why?





Thanks!

Unfortunately, it's pretty common these days for factory HU's to use a volume-dependant EQ. As you crank the volume up, the HU (or whatever is doing processing for the boston acoustics system) is literally reducing the bass. They do this to protect the factory speakers, saves a lot of warranty claims I imagine.

Yep, sounds like exactly that!

Loudness, boosts the upper and lower frequencies at low volume gradually reducing said boost to 0 as the volume approaches maximum. It's very, very common in factory head units, and hated by car audio enthusiasts everywhere because of the problem you're having. The least they could do is give us an on/off switch for it.

You may need something like a JL Fix. Set your headunit volume just below the point at which the bass volume gets reduced. You will then use the volume control from the JL Fix.