I recently purchased a 500-watt Kendwood sub and 2 12'' Pioneer subs that are rated at 50-300 watts RMS (1,200 Max) Here are links to what I purchased:

Pioneer TS-W304R Champion Series 12" 4-ohm subwoofer at Crutchfield.com

Kenwood KAC-5001PS Mono subwoofer amplifier — 500 watts RMS x 1 at 2 ohms at Crutchfield.com

I noticed that all the lights in my TL are starting to dim when I have the volume at around 11 and bass is up at around +3. Does this mean that I need a new battery or new alternator? My thoughts were to go down to my local parts store and ask them if they can test my alternator and check my battery and see if they need to be replaced. If either of them have to be replaced, what would you guys suggest to go with? I dont really want to spend money on a capacitor yet for my sound system. Thanks for the input!

 

Add a capacitor . they're like 50 bucks. make sure you fill it up before install.

eta, Im running much more off the factory alt, no cap,volume at 30. no dimming.

 

I had my battery, alternator and starter tested at my local parts store and all passed... what would be the next step? buy a cap?

 

Grounds upgrade

 

mind explaining a little more?

 

Just add a capacitor...
it's a well known upgrade, holds a charge like a mini battery to take the voltage hit of bass instead of your stock electrical system (causing the dimming).
I'd start there...
Adding the "big 3" ground upgrades are not a necessary upgrade IMO and can be done incorrectly and cause more harm than it's worth (i.e. channeling spikes through accessories instead of to ground).

 

would adding a cap be better then upgrading the wiring?

 

IMO, it would be step one.
Cheaper, and safer.
Then again, turning down the gain on the amp a little might solve your issues too.