Amp dying?

Someone help me, all of a sudden my amp after about 10-15 minutes of driving, it just cuts off and wont come back on. All my wiring looks fine so i do know what it could be? Can it be my battery dying? please help thanks. i also got a new amp and it still does that! ASLO WHEN I HAVE THE MUSIC LOUD, MY HEADLIGHTS AND INTERIOR LIGHTS ON THE DASH DIMM AND PULASTE TO THE MUSIC, WHY?

if neither amp will turn on check the fuse after the battery, and in any dist. block you have and in the remote lead behind the HU. and about the lights dimming, its because your amp is drawing a lot of power when the bass hits, and your electrical system cant handle it. the best thing to do is get a cap and/or a high output alternator.

ima try to see whats wrong again tonight, where do i get one of those caps and for how much?

Your amp is automatically cutting off because it's rated to take so many amps. I fixed my problem like that by buying a 50 cent resistor at radioshack. It has to do with how your speakers are set up (in parallel or series) and what are the ohms or your speakers and apmprage of your amp. It's been a while since I've done any electrical enenering crap so I need to go into my old school books to see how to figure out the formula to your problem. I'll post it tommorw if I have time.... oh wait, check out this site:

Understanding Basic Electricity of your Amp and Speakers (http://http://www.activebass.com/default.asp?iTarget=http%3A//www.activebass.com/articles/item.asp%3Fi%3D42)

See if you can figure out what resistor (add's more ohms to your equation) you need.

In their first exapmle, a 400 watt amp can handle two 8ohm speakers if the amp manual says there must be at least 4ohms of resistance between the positve and negitive side.

If anybody thinks I'm just talking through my a$$, step on up to the mic.:finger:

that's one way of increasing the overall resistance, but you are really just wasting some of the power heating up a resistor .... and it the amp is pretty big, the wattage of the resistor will have to be pretty big too.

Originally posted by PaulD
that's one way of increasing the overall resistance, but you are really just wasting some of the power heating up a resistor .... and it the amp is pretty big, the wattage of the resistor will have to be pretty big too.
Yeah, your right... If the amp is BIG, you can add on another speaker, since it will provide it's own resistance, but you will likely provide too much if it isn't big. Adding a resistor only compensates for the minimum level of resistance stated in the amp's manual. And since your using the formula to get the right resistor for the job, the resistor shouldn't heat up at all.

from the site :

"AMPERES is INDUCTANCE represented by I
I = E / R
I = P / E
I = square root of P / R"


NO ! Amperes is CURRENT ..... inductance is something totally different


"Now we will calculate the voltage of the amplifier and the current flow in the speakers. The name plate rating of your amp says 400 watts at 4 ohms. This is a constant and can not change so we can find the voltage of the system ..... "

Not really, if we were talking DC - his formulas would be correct. Unfortunately, we are talking AC. The impedance (resistance for DC) of a speaker varies with it's frequency ... and it can vary WILDLY over the sub range of 20-100 Hz. The box can help out a little here.


I didn't see anywhere in the site where it showed how to decide what resistor value you needed for what you are proposing. But it WILL create heat ........ the resistor works by draining voltage off of the system. The voltage across the resistor creates an IR drop - since it siphons energy off the system, it must be going somewhere since the laws of thermodynamics tells us that energy cannot be created or destroyed. It changes the form of energy from electrical to heat, pretty simple. The AMOUNT of heat is dependent on how much current is flowing thru the resistor and it's ohm value.