Hello,

I installed a subwoofer in my G and whenever the bass kicks in hard I notice my headlight would flicker a little. I know its not normal and I been looking around. Some people say getting a capacitors will help. I'm not sure if it's the alternator not giving out enough output, but plenty of my friends with junker old cars (grand am) are about to handle alot more powerful subwoofers without any mods, but most of then do have capacitors. Anyone knows what I can do? I ready have 8 awg grounding wire kit installed in the car. and the amp is tuned correctly. If I need a capacitor waht one should I get?

amp: Kenwood Excelon X1200M Kenwood Excelon X1200M Class D Amplifiers - Car Amplifiers at Onlinecarstereo.com

Sub: Pioneer Premier TS-W3002D4 Pioneer Premier TS-W3002D4 Component Car Subwoofers - Car Subwoofers at Onlinecarstereo.com

 

its your battery not your alternator that is not able to handle the power draw. the alternator just charges the battery but the battery actually holds the charge. you can a) get a better battery like a optima designed for holding more power or b) get a cap which basically acts as a second battery.

 

just get a cap

 

What kind of cap do you recommend? How many farad and what brand?

 

+1 on that!

 

As others have posted, I think a cap will solve your problem. I had the same issue with my Z before my caps were installed. I had two 1 farad capacitors and the issue became non-existent. Good luck.

 

This may be a case where a "Black Betty" Grounding kit may be of some use. Before you spend the money on huge capacitors you may try a heavier grounding wire. Just run it from the battery (-) to a big body part. It could be with a great current draw the resistance of the grounding cable has become a significant part of your circuit. Everything that draws electricity in your car uses the same return path through that cable. Make sure you clean off the connection from the cable to the battery as well. Just my opinion. If you do get an electrolytic capacitor (unlike mica/ epoxy/etc)remember they have a polarity. They can be ruined if installed wrong.

 

Wow nice setup!! This one should work right? Absolute CAP200-Silver - Sonic Electronix
I'm confused becuase i'm not sure if all cap are for 12v, I see some one them saying 20/24v DC or 16/20v DC.

 

Caps are nothing but a bandaid. The root of your problem is the battery/alternator.

 

This happened to my friend one shop said get a cap but the other shop said it's the wiring, they said when the sub is too powerfull and uses a small gauge of wire that's what will happen. My other friend got his sub hooked up then with a bigger gauge of wire and problem solved. But the cap will work too but if the wire is too small then there's still a problem

 

thats good to know!

 

I have 4awg wires connected to the amp so that should be the problem

 

I will replace my battery with optima deep cycle one once the battery dies, it might die this winter. I dont think the problem is my alternator since my amp isnt too extreme and considering this is a $30k+ car the alternator should be decent.

 

alternators aren't oversized just because the car is 10, 20, 50, or 100k in price. they are sized with a safety factor for the load engineered into the car's electronics, period.

any time you add 1200 watts to a car's alternator, you run the risk of exceeding what it can handle.

think of the alternator like a hose bib and the battery like a bucket with holes in the bottom. the amp wants lots of water to come from the battery, but the holes are only so big. so the first step is to enlarge those holes by replacing the battery with a deep cycle like a yellow top. then you'll find that when water is in the bucket and the amp needs it (big bass note), the water will rush out and fill the amp. but if you had a period of long bass, the water will quickly run out of the bucket. now the hose bib isn't large enough to fill the bucket with enough water. time to get a bigger hose bib (higher output alternator).

Hopefully all of that makes sense as an analogy.

Edit: to add the cap as an analogy. caps take more time to fill than they do to release their charge. to put into perspective as above, think of the cap as a secondary bucket, much smaller in size, but with a VERY large hole at the bottom. BUT also with a restrictive sponge at the top where it fills. you'll see that it would definitely help to provide a slug of water to the amp at a huge bass hit, but since it takes longer to fill, a sustained bass note would render it useless as almost all the water will come from the regular bucket (battery) as it doesn't have a sponge over the top to fill.

 

What this guy said!
Had the same problem on my 35 and threw in a Yellow Top. Everything was ok then. This was with a JL 10W7 and 1000.1 amp. Google the big 3 upgrade also, that can help. 4Ga. wire is perfect for the power and ground.
Capacitors are NOT worth much in my opinion.