amps/subs cutting out

[stews vtss]

my amps/subs are cutting out when up loud and when the car is idleing or the car is off the battery is new alternator is charging fine so does this mean i need a capacitor??

[acarmody]

No. It probably means your amps are getting too hot and going into protect mode. Who setup your amps, you or 'professional'?

EDIT: Can you post up the amp(s) and sub(s) specs and also what size wiring you are running.
Does it ever cut out when you are driving?

[wraith]

I agree with that statement. Make sure the gain is not up really high.

[stews vtss]

i fitted it and the gain is half way i have 4gauge running to the monoblock and 8gauge running to the 4 chann. if i just rev it a little bit or if im driving it has no problems at all it only happens if i stop after a few seconds and the dash lights dim slightly.. i got a new battery and and test done and its getting the right charge.

kicker mono block 400w running kicker comps i brought the subs and monoblock from jb and they said thats the right amp to run them. and 4 chann amp running the speakers

[acarmody]

Can you give me model numbers for the headunit, both amps, and the sub(s).

Is this your mono amp? http://www.crutchfield.com/p_206ZX40...ures_and_specs
Subs? http://www.kicker.com/comp . 12"?

Still need the H/U specs.

Also are those power cables running all the way to the battery, or do you have 1 main cable running to a distribution block?

Also Bass Boost on amp, make sure it is turned down to zero.

[stews vtss]

mono block zx 400.1 and ive got the black kicker comps in the dual box. the other amp is audioline 4x 200w "cheap sh*t" the headunit is kenwood bt8141u. the wiring is all done properly earth ect. one of my mates has this same problem when his car idles the lights dim a bit and the subs cut in and out but when driving or rev the car its fine..

[stews vtss]

the power cables both run the whole way to the battery seperate and the subs are kicker comp c12s. the amps dont get overly hot just seems like they have lack of power maybe?

[PRAVX II S]

A 1 Farad capacitor or a second battery will help with the dimming.
At idle when the alternator is turning slowly the output will be reduced (Current is reduced to battery)
And when you take of the revs are higher and the alternator is turning faster the output will be higher (Current is higher)
So this is why it is dimming at idle. The alternator needs to run the factory electronics as well not just the sound system.

[wraith]

Have you got it decently grounded. I have had this problem before and it turned out it wasn't earthed properly.

[stews vtss]

yeah the earth point is good. i mite try the capasitor idea and see what happens.. thanks for everyones help

[acarmody]

A capacitor will be a waste of money in your case. A capacitor does not create power it just stores it so that it can be discharged in the case of a fast bass hit, but it still gets its power from the alternator and battery. Your system is low powered enough that the battery alone should be fine. A well running battery would easily be able to supply the amps that your system running at maximum volume would require. The fact that the alternator (even at idle) as well as the battery cannot supply enough power to the system indicates to me that the problem lies elsewhere.

Are your ground wires the same size as your power wires? And where are they grounded too?

[stews vtss]

yes they are but i will go over everything tomorrow to check nothing has come loose and ill see if i can pin point a problem with it

[PRAVX II S]

When the car is idling the alternator does not produce high current charge.
The battery should have reserve power from the alternator charging it combined with low current charge of the alternator to supply power to the electrics at idle and sound system in your case.
When you take of the the RPM are faster and in turn the alternator will produce more current to the system. You said in your post that when you rev the car it stops diming because of the higher alternator output. I would check all the cables connections and put in a second battery.

[stews vtss]

is putting another battery in as simple are just linking them up??

[PRAVX II S]

You have to wire the batterys in parallel.

[holdenboy]

Yep i agree with acarmody here, i had a 4000wrms amp running at 0.5 ohm off a standard battery in my VR, so basically drawing 10x the amount of current you are.....never had a problem like this one.

Before going out and buying a second battery or capacitor, double (even triple) check your power connections and the battery and amp, along with the earth connections.
A good test to do is get a multimeter, with the car on and idling crank the system to a reasonable (1/2-2/3rds) level. Now with the multimeter check the voltage at the battery, make a note of it. Then do the same at the amps terminals using the same section of the same song. The voltages should be within 0.2-0.5v. If not then its a wiring / connection problem.

[stews vtss]

ahh yep im gonna check it all over again tomorrow but just noticed the bass boost was set to half way so i turned that right down so im hoping if i check the wires ect that it should be ok now thanks for everyones help

[stews vtss]

it seems that it was the bass boost being to high. i should of relised this..... thanks for everyones help

[holdenboy]

Hmm, well it shouldnt be the problem. It will reduce the amount of current your amplifier draws which will "fix" the problem. But im almost sure that wasnt the cause.
Anyway, if youre happy then thats all that matters

[stews vtss]

i still have this problem i had a brand new century 58vt with 470ccas battery in my car and on the weekend i put a bigger battery out of a 4wd in it and this fixed the problem so hopefully i can return the battery and get a bigger one for it...