Alternator/ subs and amp

[bigsteve305]

I have some subs and amp and when I put the base and sound up my headlights, dashboard lights ect. Starts to dim to the base. I bought a compacitor 3000 watts and the lights still dim could it be my alternator is the sound system going to make my alternator go bad or is it already??

[MattsLincoln]

time for a 130 AMP 3G alternator swap.

[85crownHPP]

What size power/ground wire are you using? How powerful is the system? To small a gauge of wire or poor grounds can cause a voltage drop too.

[sly]

the stock alternator is the 130/135 amp version (he's got a 2000 whale) and this can be upgraded to 220 amp service with just a swap (they're kinda pricey though - around $225 with shipping - one from Amazon or if you're ok with ebay... $170 for a 240 Amp). If you're using 3000 watts of amps... you'll need at least 6 gauge wire (or fatter) going to the capacitor and then to the amps. My amp is only 760watts and I have two 10 gauge wires run to it (equivalent to one 8 gauge). I probably could have gotten away with two 12 gauge wires, but I prefer to have a little overkill. I don't have a capacitor on mine and it will dim the lights a bit when I crank it up. I would guess that you just need to make sure you're running good enough wire to the capacitor and amp as well as ground for the amp. If all the wire is in order, then you probably need to up the ante on the alternator.

[bigsteve305]

I don't know what type of wires I have but I got to 12 cvr kickers with a 1000 watt amp for 12s it thumps pretty damn loud. So I probably need to change the alternator

[sly]

the wires might have the AWG ## printed on them. If it's at least 6 or 8, you're good in that area for 1000W.

these are 3-4 mm in diameter (the stranded wire only... the insulation doesn't count)

[zoomie]

personally, anything over 250 max and i use a 4 ga. wire. make sure your ground and your pwr wire are the same size. and just a personal tweak, my ground wire is usueally no longer than 10 inches or so.

[SVT98t]

This is the point where I say listen to Slymer.Trust me.
And I agree with him.
Try PAperformance.com. They sell some pretty bad-ass alternators.

-ryan s.

[sly]

I've heard of too many issues with PA's alternators lately. And they're a little too proud of them for my money.

[TechSys]

Basically your electrical system needs to be boosted. First off, get rid of the capacitor, they are useless in the car audio environment (besides, your amplifier is already full of them).

2 to 4 gauge wiring on both positive AND negative wires. Keep the negative wire as short as possible and go for the best ground area you can find (preferably frame).

Big 3 upgrade with the same size, or larger, wire you used for the amplifier.

Maybe another battery, wired in parallel with the battery you currently have. (parallel wiring will give you more amperage but keep the voltage the same. example: 1 12volt battery @ 1000amps will only give you 1000amps. 2 12volt batteries each 1000amps, wired in parallel, will give you 12volt 2000amps. Yes, you alternator can handle charging 2 batteries). What kind of battery are you currently using? If you do decide to go with another battery, try to make sure both are the same.

Properly tune your amplifier. The gain is not a volume control even though it acts like one.

I could go into more detail but it could end up being a very long read.

[sly]

First off, the capacitor is not useless. It allows charge to be stored for faster use than the battery can provide. This is very common knowledge among audio gurus and electrical engineers (myself).

Overkill on wires however can be a good thing. Though if he's only using 1000W peak, that's only going to draw 83.333_ Amps peak at 12V. at 14.4V it's only 69.444_ Amps. Power = Current * Volts. This can be covered by using 3 10 gauge lines with 30 amp fuses (readily available even at wal-mart) or a single 6 gauge line with a 100 amp megafuse (typically have to get more specialized in stores to get these - auto parts stores - battery cables and bolt-in-line megafuse).

There will be some resistive loss over the wire, but it will not really factor more than a few milliamps in the lengths dealt with in a car. Piss poor connections/terminals will cause much more issue with resistive problems.

fitting a second battery is typically not something most people do with less than 5000W and even then most won't do that with less than 10,000W. They will add second/third/etc alternators first. There's typically more space under the hood for extra alternators (with proper and usually custom brackets) than room for extra batteries.

Properly tuning the amp is good advice, though. The best way to tune it is to get your favorite song and make it sound right with that. You typically don't want to turn the gain knob past about 70% though... it will be much cleaner and will have less distortion.

and yes, many of us could go into more details... but we're trying to minimize out of pocket cost. Wire is a lot cheaper than batteries and alternators.