Headlights Dimming At Volume

[Space Ninja]

Hey Guys,

Just a quick question - at the moment when I turn my stereo up a bit higher than ambient, I've noticed that my dash and my headlights dim slightly when the bass kicks in.

The setup I have currently is just a Panasonic head unit, and a Pioneer 700W Amp powering a Sony sub, the other speakers in my car are run off the head unit.

I'm wondering if a capacitor will solve my problem of my headlights dimming or if it is something else I need to check out? I replaced the battery in my car in Feb as well if that is of any consequence.

Thanks in advance for any advice!

[heslo]

Should do the trick mate, got the same problem here. Just haven't gotten around to fixing the problem

[frx026]

Hi Space Ninja,

With your headlights dimming a capacitor will not help in this situation.

The Job of a capacitor is to provide a quick discharge of current to a high current device, like an amplifier. You might find that the cap will help you for 10 seconds or so, but for the long run it will not work.

The way to fix the problem is to

- upgrade battery

- upgrade earth between battery and car chasis

- upgrade the charge wire between alternator and battery

- change regulator voltage from 12v to 14 v ( this charges your battery at a higher rate)

It's a lot, but i can tell you from my experience over the 10 years or so that a capacitor has never resolved this problem in any model of car.

Cheers

frx026

[R32 TT]

Hey Guys,

Just a quick question - at the moment when I turn my stereo up a bit higher than ambient, I've noticed that my dash and my headlights dim slightly when the bass kicks in.

The setup I have currently is just a Panasonic head unit, and a Pioneer 700W Amp powering a Sony sub, the other speakers in my car are run off the head unit.

I'm wondering if a capacitor will solve my problem of my headlights dimming or if it is something else I need to check out? I replaced the battery in my car in Feb as well if that is of any consequence.

Thanks in advance for any advice!

Hi mate,

Actually a big cap is exactly what you need.

Yes, of course improving your earth, and wiring etc is certainly going to help - but a bigger capacity battery is actually only "more" load on your electrical system.

The battery is "in use" so to speak when your car is not running.

When your car IS running, then the Alternator (which is above battery voltage) is supplying all the "loads" in your car. Loads include your dash lights, headlights and so on - your car amplifier of course - and, your battery - because the alternator is trying to "charge" the battery. A bigger battery can demand more to be charged than a smaller one.

Anyhow - getting back on track.

Most loads in your car draw current in a constant sort of way. Your amplifier is the one that doesn't and will demand current in a dynamic way. Naturally the Bass takes up big chunks of power which is hard for the electrical system to keep up with. A large capacitor has the ability to release a great deal of current extremely fast and so can help "fill in" these sudden demands on current. The electrical system usually has enough time "in between the beat" to top up the Capacitor for the next beat.

You just need to make sure you have enough "cap" for the demands and see that the wiring from the cap to the amplifier is sufficient.

Easy test - get the Car Audio place to run the wires around the outside of your car and wire up a cap into your amp and see if it makes a difference. If they want to sell you a cap - its an easy 10minute test?

M

[jackson 33]

no no no u don't get a cap, your lights are dimming because your little battery can not put out many amps. upgrade your battery. My bettery in my R33 GTST can put up with its high beems and the eclipse 1500watt sub at its max and all my 6 speakers are amped up. And i can still start up my car after.

[Chris Rogers]

actually - battery and earth do the battery to body and the body to engine one with 2awg or better cable that will fix the current loss . bigger battery would be on the cards also as soon as you notice the dimming.

caps are a patch for a MUCH bigger problem and 99% of the time are NOT needed.

[SKY 34]

Light dimming, obviously you do not have enough power for the system you are using. Earthing is really important…use the Raizin Volt stabilizer, see if it is enough

http://www.the-pivot.co.jp/product/se/raizin-e.html

If not, it entirely depends on the usage of your sound system…

If you listen a lot to music with heavy bass such as R&B where a lot of power is required for the subs then you’ll need a good battery and a capacitor.

On the other hand if you listens to Michael buble, or Norra Jones, where minimal bass is required, then a good battry is sufficient

However before buying do consider these...

1- cheap capacitor

a sub-quality capacitor provides extra power in the form of pulse...so it's not a continuous thingy...like what frx026 said....prolly 10secs? you can get these for abt $150?

2- Good quality capacitor

A better quality capacitor provides continuous power...however these cost around $350 and on top of that these capacitors are thirsty..they store the power for Infrequencies (when you turn on your sub hard)....the alternator in turn take more power from the battery...

The battery is meant to be charged by the alternator..howerver the capacitor will suck more power than the alternator could generate…which results in having a flat battery within 1-2 month

3-Installing good quality battery

Usually a more expensive battery are designed to go flat charged and flat and charged…for multiple charging… i.e you can always have a jump starter pack and when battery went flat just jump start.

4- Installing good quality battery

The amps will draw power straight from the battery depending on the type of amps you’ve got…there are two types…

a) where watts depends a lot on voltage (such as Soundstream)

b) where watts does not depend so much on voltage (such as JL)

For type a) small battery would affect the sound quality substantially…..

5- Most importantly

The capacitor although stores power, In the end the power source come from the battery.. having a good capacitor with a bad battery will be pointless…

[Chris Rogers]

walks away shaking head....

(a cap is NOT needed here!)

[Space Ninja]

Hmm interesting, a lot of divided opinions - but from the sounds of it, even if I got a capacitor, it would only be a stop-gap measure.

I replaced the battery in Feb and I had an auto electrican re-do the terminals and wiring for it in the boot. Would there be any benefit from replacing the wiring between the battery and amp/sub ? At the moment it doesn't look that fantastic, but its not that bad either.

As for a better earth from the battery to the car, I'll check this out and see if I can make it any better - From what I remember I think it was pretty decent (I think the auto electrican did that at the same time)

[VB-]

Stop lights dimming

something i came across when trying to learn about car audio myself. this article is short and simple, but my knowledge increased 10 fold from it. it says it all in the last two paragraphs:

In 99% of cases these simple steps will solve any problems you have with lights dimming, etc. Caps are worthless, spend the money on cable or battery upgrades.

And remember, I run 5000WRMS (380A current draw) into a pair of 15"s, 400WRMS into a 6" front stage (100A current draw) and a pair of Hella 100WATT spotlamps for a grand total of around 500A of current draw @ full song...

All off a single Odyssey battery & stock 60A alternator without the headlamps/spotlamps dimming at night.

capacitors... lol

[Fhrx]

To solve the afore mentioned issues we quite often install earthing kits. This assists in solving many of things mentioned in the post above.

For a little more information read these at your leisure:

http://www.fastfoursforumscarclub.com/temp/ground_2.jpg

http://www.fastfoursforumscarclub.com/temp/ground_3.jpg

http://www.fastfoursforumscarclub.com/temp/ground_4.jpg

http://www.fastfoursforumscarclub.com/temp/ground_5.pdf

For photos of them in situ see here:

http://www.fastfoursforumscarclub.com/temp...asp#interest8_4

Edited April 27, 2006 by Fhrx

[jasont82]

what is a capacitor for? if its not to take load off the battery and alternator what does it do? im confused. everyones got there opinions on how to fix the problem but those that are against a capacitor, what do they do if there a waste of money? why would you need one? i always thought the bigger gauge wire you use the better current flow you get. but theres too much current being demanded if the lights are dimming so how is bigger wire gonna help? im not trying to be smart i seriously dont know what the answer is. i was told you need a bigger alternator for dimmiing lights but thats just what i was told.

[VB-]

what is a capacitor for? if its not to take load off the battery and alternator what does it do? im confused. everyones got there opinions on how to fix the problem but those that are against a capacitor, what do they do if there a waste of money? why would you need one? i always thought the bigger gauge wire you use the better current flow you get. but theres too much current being demanded if the lights are dimming so how is bigger wire gonna help? im not trying to be smart i seriously dont know what the answer is. i was told you need a bigger alternator for dimmiing lights but thats just what i was told.

a capacitor just stores up electrical energy, then will release it on demand (like a big bass note) as not to suddenly place massive strain on the battery, and in theory, they're a great thing, but in reality, it seems most people agree, they dont do jack sh*t. maybe in a competition SPL car or sumthing, where they use quick 'burps' to get their highest SPL, it may benefit them, but as an everyday hting, they dont really do that much (thats the general consensus, i've not had any real experience with them).

in alot of cars, the stock alternator will be ok for even some serious stereo upgrades (read the quote in my previous post). my understanding of the bigger earthing is that the stock earthing is the thing that cannot carry enough current, not the alternator being too weak. think about running very small fuel lines to your fuel rail. u may have a bosch 044, but it still wont do anything cause the lines can't carry the fuel. gurus please correct me as im sure sumthin above is wrong