Some advice please

I have a 96 honda accord lx, I have put a sound system in it. The amp is
pushing around 900 watts RMS. Which is constantly. Anyways of coarse I know
my lights and stuff are going to dim. But my rpms drop when the bass hits
almost to the bottom line. I just installed an capasitor, but only helped
alittle with everything but not much. SHould i upgrade the battery or beef
up alternator? Also will this wear down the alternator more or possibly mess
up the engine somehow? Please help!

 

On Sat, 24 Jan 2004 01:50:51 -0600, amsjsj wrote:
.. SHould i upgrade the battery or beef

Both. Get the highest amperage alternator you can find and a really stout
battery. Consider installing a dual battery setup. This is gonna be
expensive, but you already knew that, didn't you?

You might also want to ask your questions in rec.audio.car.

feroce

 

GET RID OF THE AMP AND GIVE THE PEOPLE IN YOUR NEIGHBORHOOD SOME PEASE. IF
YOU WANT LOUD MUSIC AND RUIN YOUR HEARING GET A SET OF EARPHONES.

 

touchy subject i see. Just because he has a system doesn't mean everyone in
the neighborhood will hear it, i have one and id doubt anyone in my
neighborhood even knows about it.

 

yeah my systems only turned on outside my neighborhood, now who wears head
phones when they are driving?

 

what would eventually happen if i dont?

 

What about the people in the neighborhood where you're driving, you
inconsiderate asshole?

Bearman

 

What kind of trouble you are in here depends very much on how you are
using the system. If you have an optimal class B amplifier and you are
getting 900 W delivered to your speakers, you are blowing another 256 W
as heat in the amplifier output stages. This means a total power of 1146
W or 79 Amps at 14.5V. (In reality amplifiers are not optimal, so you
need more power).

When you hit the bass notes the alternator will essentially be
full-fielded in an attempt to deliver the required power. This power
comes from the engine, and if you are at idle you will certainly see the
RPM drop. Ironically this will only get worse with a bigger alternator.
Full fielded at idle the stock alternator will produce perhaps 30A for a
power of 435 W. That means that the maximum load it can put on the
engine is about 3/4 horse power (assuming 80% efficiency). The
additional power (to make up the total 1146 W required) will come from
the battery. If you put in an alternator rated at twice the amperage,
you could get perhaps 60 A at idle, or 870 W. You will need less power
from the battery, but the alternator will try to pull 1.5 HP from the
engine. This will drop the RPM even more.

The RPM drop really is something you'll have to live with if you try to
draw that much power. You should adjust your idle speed to the high end
of the specified range, but don't go much above that. Going too high on
idle speed will cause the control loop in the ECU to go unstable (and
you'll get surging idle). Giant capacitors will help (I am sure you know
that they should be mounted right next to the amplifiers) but not
eliminate the problem.

Your real concern should be to keep your battery charged. If you are
cruising along with the stereo blasting at full power, you will de
discharging the battery while driving. The only cure for this is a
bigger alternator (which as I mentioned would not help the RPM drop). A
bigger battery would not do much.

If you run the system at full power only rarely (I can't imagine it
being bearable to sit in the car with a 900 W stereo on full blast) you
may not need to make any changes at all.

You will also have to accept that the alternator will be worn out more
quickly than it would without a monster sound system. Same goes for
battery.

 

You will kill your battery and alternator for sure. Best thing for you to
do would be to take it to a shop that specializes in high-end car audio
and get some professional advice.

feroce

 

I dont drive through neighborhoods all day dick head. I love pissin idiots
like you off!

 

thanks for the advice man thats what i needed to know, Well there are
optimum or something like that batterys that are designed for systems but
never tried it yet it doesnt really make sense but i dont know how they
work.

 

Hee! Hee! Hee! It's not working.