ok so i had 3 10w3v3's running off an arc audio KAR 900.1 in a sealed box
bass use you dim the lights slightly at full tilt

now ive switched to a ported box 4.3 cubes at 36hz and the lights dim at half tilt and if i really turn it up the volt meter goes bananas lol

im thinking i should go over the wiring again anyone else???

 

Double check your sub wiring. Did you move the amp or change any settings? Check your gains, bass boost and your grounds as well.

 

your alternator is dying.

 

could be possible that the overall impedance changed when the subs were hooked up again.

but i still stand by the previous post. your alternator has progressively gotten worse at charging the system.

 

If nothing changed, the subs in ported box became more free with movement, and started to demand on the amp more to keep control at higher excursion. So the amp started to draw more power to convert more power to the subs. That is all.

 

Back the gain down a little, you may be driving the amp a little too hard.
You dont need to drop it down all the way, just a little to get rid of the dimming.

I set my gain with an O-Scope, 40hz tone with a 10dB overlap.

Oh and how's that box working out for you?
I wouldn't mind hearing it.

 

I agree Sasha

 

the box is loud as a mother!@#$% lol great job scared a couple of buddies
and i was thinking it was the alternator as well im gonna try the big 3 and maybe switch from a 4 guage amp kit to a 0 gauge
the only change in the amp is turning on a subsonic filter