Changed sub box and now my lights are dimming bad?

Question

Trying to figure out what to look at for the cause.. I had my kicker L7 in a ported box, and swapped it into a sealed enclosure to see which sounded better. All my settings are the same, wiring the same, but I played a few songs and my headlights and dash dim to almost shutting off, even at low volumes it dims pretty bad. They dimmed very very little at high volume only before in the ported enclosure. What could be the cause?

Eat Drink Smoke Sleep Repeat · Answer

How many things are running on the alternator buddy?

A 1000 watt microwave?
A 100 watt TV?
A 2000 watt 12V to 120V power inverter?
A 2000 watt monoblock amplifier?
A 500 watt 5 channel amplifier?

Pretty soon, you’re gonna be DEAD out in the middle of the road. The alternator’s life is coming to an end. Get a HIGH output alternator and do the big 3 upgrade with 0 gauge OFC wires.

N2Audio · Answer

Could be as simple as a power or ground connection getting jostled and creating some resistance.

However, impedance of a subwoofer can vary drastically depending on its enclosure.

Would need to know enclosure specs of both your boxes to speculate on the relevance of that.

The Devil · Answer

Speaker efficiency has changed. The sealed enclosure needs more power to do as much work as the old one. Ported enclosures, when properly designed, usually perform with better efficiency than sealed ones. Imagine if it was you running down the street. That's the ported enclosure. Then imagine you're running up a hill with a big sack of potatoes. That's the sealed enclosure. Also, check your wiring again to be sure you didn't change something. Maybe you changed from series wiring on the voice coils to parallel and dropped the impedance, causing an increase in current draw for your amp.

Anonymous · Answer

Alternator is likely fried.  Check the voltage when engine is running and when the stereo is playing.

Changed sub box and now my lights are dimming bad?

4 Answers