# Dimming lights when bass hits



## ladybunnz23 (Jun 26, 2003)

Was wondering if my headlights dim when my bass hits, is this hurting anything and what can i do to prevent this?

Thanks in advance


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## xt_out (Jun 23, 2003)

get a power-cap. they're like $150-200 for a cheaper one.
what it does is stores power and provides that extra punch when the bass hits, relieving the strain on your electrical components as well. hope that makes sence, i know its not a very good explananation but i just woke up


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## AZ02SpecV (Dec 23, 2003)

xt_out said:


> get a power-cap. they're like $150-200 for a cheaper one.


holy shiot man!!! I can get u a capacitor for much less than that. I get them all wholesale. 

And basically, the way a car's electrical system works is it's not designed for sudden draws of current that your amp demands when the bass hits. So what a cap. does is store a charge for the amp to pull the sudden surge of power it needs instead of from your battery and alternator. Extended over-pull on the alternator can result in a damaged one (I speak from experience trust me). How many watts are you running?


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## Punkrocka436 (Jul 8, 2003)

dont get a capacitor.

Upgrade your grounding points. and so a thing called "The big three" that the people over at sounddomain do.

-Upgrade your battery to chassis ground to 2 or 4 gauge wire.
-Add a second fused wire(2 or 4 gauge) from the positive alternator terminal to the positive battery terminal
-Upgrade the engine block to chassis ground wire with 2 or 4 gauge wire

Capacitors rarely fix a dimming problem so i wouldnt even bother. Spend the 10 dollars for some 2 gauge wire other than the 100 dollars for a 1 farad cap


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## sr20dem0n (Mar 19, 2003)

Punkrocka436 said:


> dont get a capacitor.
> 
> Upgrade your grounding points. and so a thing called "The big three" that the people over at sounddomain do.
> 
> ...



yep, caps are a waste


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## AZ02SpecV (Dec 23, 2003)

Punkrocka436 said:


> dont get a capacitor.
> 
> Upgrade your grounding points. and so a thing called "The big three" that the people over at sounddomain do.
> 
> ...


depending on the size of your system(watts) and how hard and often you pound it...that could be a bad idea. Doing that only allows for more power to be drawn from your alternator since there is less resistance. If your alt. is not rebuilt, the stock one may not be able to produce enough amperage to power the car and your amp as the bass hits. hence the dimming of the lights. there is a reason that wire is the gauge it is.... It will definitely work a lot better than getting a cap but could produce bigger problems down the line i.e. blown alt. I would suggest getting your alt. rebuilt b4 doing this. that's why i asked how many watts he had. Also wut kind of music do you listen to? If it's a lot of rap with long bass lines and such that will be really hard on your alt. that's just my advice, take it as you will........


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## jayrok (May 25, 2002)

Get a 200+ amp High Output Alternator...Mine never lets me down


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## NotAnotherHonda (Aug 7, 2003)

yea i have a 1 farad RF digital cap for my 2 power RF 1000's, and my lights STILL dim...im gonna re-do my grounds AGAIN...damn...i need a new alternator...maybe a 200amp...anyoone know where i can get one?


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## AZ02SpecV (Dec 23, 2003)

NotAnotherHonda said:


> yea i have a 1 farad RF digital cap for my 2 power RF 1000's, and my lights STILL dim...im gonna re-do my grounds AGAIN...damn...i need a new alternator...maybe a 200amp...anyoone know where i can get one?


first off: if you're running 2000 watts... ofcourse your lights are going to dim on a stock alt., and a 1 farad cap isn't going to do squat for 2000 watts either. With that much power I'd suggest getting a H.O. alternator, and a Optima Yellow Top in the trunk, and then def. upgrade your ground points and such. 

check out these sites:
www.alternators.com 
www.hoalternators.com 

there are also places where you can just get your OEM alt. rebuilt but i don't think it will be as much of an increase as a new one. maybe 160-170 amps.


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## NotAnotherHonda (Aug 7, 2003)

yep...i already got a red top...and i cant put 2 batteries in my car...fuck all that weight...oh yea..pics are up of my fiberglass system that i did myself..look in my sig...peace
tommy


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## Sethticlees (May 30, 2002)

Punkrocka436 said:


> dont get a capacitor.
> 
> Upgrade your grounding points. Capacitors rarely fix a dimming problem so i wouldnt even bother. Spend the 10 dollars for some 2 gauge wire other than the 100 dollars for a 1 farad cap





sr20dem0n said:


> yep, caps are a waste



Wow! Is that true...?

Hey, what about AlumaPro "The Cap" rated at 15 frad. 
Wouldn't this be more worth your while (nevermind the $500 price tag)?


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## Slayer2003 (Jun 4, 2003)

......unless your sporting a 5k watt+ system, which im sure you're not...caps are a waste. the biggest reason stores and shops will tell you you need one, is they work commission.


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## NotAnotherHonda (Aug 7, 2003)

Theoretically, the cap makes sense...thats why i bought one...that, and the fact that the digital status shit looks goos...haha...but yea, the cap didnt help at all, and like i said before, the alternator is your main source for power besides your battery...the guys at best buy or whatever will tell you all this shit that makes sense if you think about it....like how it saves power all the time so your bass doesnt take alot of power here, a lil power there, so your lights lack power sometimes, and sometimes they dont...but even though it sounds good, they usually dont work...
the 15 farad cap has alwats made me laugh...cause at the audio store, itll be like, half farad...then 1 farad, then a big ass 15 farad...what the fuck ever happened to a 2 farad? dammmmnnnnn...i dunno how good those work...but geez......


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## AZ02SpecV (Dec 23, 2003)

NotAnotherHonda said:


> yep...i already got a red top...and i cant put 2 batteries in my car...fuck all that weight...oh yea..pics are up of my fiberglass system that i did myself..look in my sig...peace
> tommy


a red top does nothing for systems. it's only good for starting. your car. a yellow top is a deep cycle high capacity battery that will store a lot more "juice" than any regular battery. With my yellow top, I've actually bumped my system for a couple hours with the car off and it started right up. Try doing that with any other battery, including the red top. 

having a yellow top in the trunk will act pretty much like a cap in that it stores power but unlike a cap, the battery doesn't lose it's charge, and has a much larger capacity. 




Slayer2003 said:


> ......unless your sporting a 5k watt+ system, which im sure you're not...caps are a waste. the biggest reason stores and shops will tell you you need one, is they work commission.


correction: if you have a 5K+ watt system then caps are a waste....at that size you need extra batteries....

honestly for systems up to about 800 or 1000watts RMS a cap is a good idea. i don't know why you guys say it's a waste and everything. While it may not cure your light dimming problem, it maintains an even voltage to your amp. Because most amps will produce more power at 12-13 volts than they will at say 11 volts. When the bass hits in your car(and your lights dim) your voltage also drops. Therefore your amp does not produce as much power. I def. noticed a dif. when i put a cap in my car *shrugs* 

But hey who knows, I could just be telling you this to get the commision.........


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## mirrortints (Aug 15, 2002)

Okay, first off, it all depends on your system. If you have a cheap amp then it is drawing a lot of distorted power, that could lead to the lights dimming. But most likely its the amperage factor. 

Listen to the guy that said to upgrade the big 3. This is very very easy to do. I got a 2001 SE and the battery ground is easy to find, then where it is grounded at, that's exactly where the engine is grounded at. Just follow that wire and add a second ground wire to it, same for the batt, just add a second 2 or 4 ga wire to it. 

Then I would get the optima red top. It does send out more amps quicker than a stock batt, plus it doesn't leak!!! My nissan batt was always gettin acid formed on the top and this Optima is the best. But remember, when you order the optima you want the "orange" top battery. They have reversed terminals so that it fits and you don't have to try to replace stock wiring or stretch the stock wiring. 

Do that and you should be okay. I got a audiobahn 1200x1 amp (put into about 900rms right now, since its hooked up into a 1.33 ohm load), plus a 300x4 rms 4 channel amp (for the front and rear speakers) and I have upgraded 2 of the big 3 (need to go buy some more 2 ga from www.knukonceptz.com, cheapest place for wires). I haven't upgraded the wire from the alt to the batt yet, plus I do have the optima "orange"(since that's what it used to be called, till the started makin it red too, guess orange was too ugly). I haven't had any problems with the lights till I turn it up too loud and distort my sound, which I ain't gonna do anyways.


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## sr20dem0n (Mar 19, 2003)

AZ02SpecV said:


> depending on the size of your system(watts) and how hard and often you pound it...that could be a bad idea. Doing that only allows for more power to be drawn from your alternator since there is less resistance. If your alt. is not rebuilt, the stock one may not be able to produce enough amperage to power the car and your amp as the bass hits. hence the dimming of the lights. there is a reason that wire is the gauge it is.... It will definitely work a lot better than getting a cap but could produce bigger problems down the line i.e. blown alt. I would suggest getting your alt. rebuilt b4 doing this. that's why i asked how many watts he had. Also wut kind of music do you listen to? If it's a lot of rap with long bass lines and such that will be really hard on your alt. that's just my advice, take it as you will........



What??

When the bass hits your amp sucks a lot of current from the batt/alt. When a lot of current is running through a small wire you get a voltage drop, this voltage drop causes your lights to dim. When you upgrade the wiring the amp doesn't pull more current, it still pulls the exact same amount and your alternator is still working the exact same amount as before. The only difference is that now you don't have a 2V drop on the path from the alt to the batt (the alt is at 14V but the batt is only at 12V because of all the current flowing through the alt to batt wire causing a voltage drop), so your lights receive their full voltage and they don't dim.





AZ02SpecV said:


> honestly for systems up to about 800 or 1000watts RMS a cap is a good idea. i don't know why you guys say it's a waste and everything. While it may not cure your light dimming problem, it maintains an even voltage to your amp. Because most amps will produce more power at 12-13 volts than they will at say 11 volts. When the bass hits in your car(and your lights dim) your voltage also drops. Therefore your amp does not produce as much power. I def. noticed a dif. when i put a cap in my car *shrugs*


They really do nothing for your amp power at all except for smooth out some of the peaks (this goes both ways, it will make the voltage lower where it would normally be higher as well as making the voltage slightly higher where it would normally be lower). You might notice less dimming because the voltage is more constant, even though this constant voltage is actually LOWER than the normal voltage your amp would receive (at parts of songs).

Here's a little math for you, with just a cap and the amp (typical RC circuit, ignoring the battery since we're simply focusing on the benefit of a cap) the voltage follows an exponential decay depending on the capacitance of the cap and the input resistance of the amp. Say you have a typical 70% efficient 1000 watt @ 12V amp, just by a little calculation you can find that this amp will pull ~120 amps at full tilt. If 12V are applied across a resistance and 120 amps flow as a result, the resistance is .1ohm. For a typical RC circuit, the time constant of the exponential decay is RC, and the voltage is normally decayed down to nothing after ~5 time constants. So if you have a 1F cap, your time constant is .1 seconds, this means that after .5 seconds your voltage has decayed to nothing and your cap is now another strain on the electrical system as it tries to recharge itself. So you spend all this money on a 1F cap for what, a half a second of benefit before it starts sucking a crazy amount of current itself trying to recharge, dropping your voltage even lower than if it wasn't there in the first place.

There have been tests done by professionals that show back to back results of a system with and without a cap and I think on average the run with a cap was .1V higher than without. It's late, so if anyone wants to read this article just ask and I'll find it in the morning.


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## Sethticlees (May 30, 2002)

sr20dem0n said:


> It's late, so if anyone wants to read this article just ask and I'll find it in the morning.



^
Very interested! 

thx


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## ladybunnz23 (Jun 26, 2003)

thx guys for all the insight..i think i from this i should be able to fix my problem.


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## sr20dem0n (Mar 19, 2003)

here is that test, I had to dig up one of my old posts on another forum to find it, I should really bookmark this thing

http://www.welcometotheden.8k.com/caraudio/Captest.pdf


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## Sethticlees (May 30, 2002)

^
That’s an interesting test!
I personally would have liked to seen more info, but I guess they got their point across. I'm a little skeptical seeing how the tests seem very amateurish, not to dog them for trying, but I would have liked a more methodical approach using different equipment, caps, cars, amps. 
Still the findings seem legit. 

Checkout their web site, I found it was full of interesting facts and information about car audio. http://www.welcometotheden.8k.com/caraudio/


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## bradg (Dec 28, 2003)

okay, get a bigger alt, try a 150-200 amp alt, up-grade all your power and ground wires under the hood. Get a yellow top battery, run a nice big power wire, get a big 3 farad cap and make sure you make good grounds, scrape away the paint from the metal.


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## sr20dem0n (Mar 19, 2003)

bradg said:


> okay, get a bigger alt, try a 150-200 amp alt, up-grade all your power and ground wires under the hood. Get a yellow top battery, run a nice big power wire, get a big 3 farad cap and make sure you make good grounds, scrape away the paint from the metal.



Maybe if he wanted his electrical system to handle 5kw daily....damn talk about overkill


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## Punkrocka436 (Jul 8, 2003)

did you read the article, like Myself, Sr20demon, and others said, caps are a waste of money. The only real reason i can see adding a cap to a system is for looks


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## sr20dem0n (Mar 19, 2003)

Thought I would add that I got a DMM for christmas so I've been running around measuring everything I can find. With the car off I get 12.5V at the amps, with it idling and the system off I get 14.5V at the amps, with it idling and the system playing a 30Hz sine wave at full tilt I have a solid 14.1V at the amps. This is stock battery, stock alternator, a highly underrated 800x1 rms amp, and a 125x2 rms amp. I have a separate 4ga power for each amp and the only electrical system upgrade that I've done is a 4ga wire from the neg terminal on batt to ground (along with the stock ground).


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## 92 Sinatra (Jul 9, 2002)

*Where can I get the right hot alternator for my car?*

Here's what I want to know:

Where can I get a high-output alternator that will bolt straight into my car? I'd rather not get one custom-wired at a shop, and I don't want to have to use special brackets or worry about overvoltages.

I see that many such alternators are listed for lots of American pickups, almost all Hondas, Camaros, etc—but I can't find one anyplace for my vehicle, which is a 1992 Sentra XE (B13 chassis, GA16DE engine).

My stereo system (for which I have all the parts, but which I have yet to install) includes a 70-watt stereo amplifier for the front speakers, a 15-watt stereo amplifier for the rear speakers, a 100-watt bridged mono amplifier for the subwoofers, and a 1-farad stiffening cap. I don't usually run my volume anywhere near wide-open, so I don't think I'll need any 300-ampere monster; however, since I run the air conditioning 10 months out of the year, I think I could probably use a little extra juice.

I'd appreciate any well-informed help anyone might offer.


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## mirrortints (Aug 15, 2002)

That's not enough amps to even start to look into new alternators. If you get lights dimming from that, you will probably just need to upgrade the wires from the - batt to chassis, and engine to chassis. I really REALLY wouldn't start to worry about new alternators unless you get into the 500+ RMS stereo range for that year of Sentra. The cap, you don't even need that. If it's still in the box, I'd return it.


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## Matt93SE (Sep 17, 2003)

also note the test by Rich Clark linked above was using one of the crappy 14F CARBON caps, not a good electrolytic. I'd like to see the same test performed using a high quality 1 or 2F electrolytic.


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## 92 Sinatra (Jul 9, 2002)

Matt93SE said:


> also note the test by Rich Clark linked above was using one of the crappy 14F CARBON caps, not a good electrolytic. I'd like to see the same test performed using a high quality 1 or 2F electrolytic.


Bass transients indeed draw momentary FAST jolts of current. And capacitors such as the one I'll use (a Lightning Audio 1F electrolytic job) ought to help; it certainly will not hurt anything. Maybe 1F is overkill, but this is my money, so I'll fill the current demands as I choose--and I want to keep my car running for another good twelve years or longer.

As far as any part of a sound system being for looks--man, that is the very least of my considerations! I do a sharp installation because that is my nature. If my best friends want to see the innards after they hear the real proof--which is, of course, the quality of the sound and nothing else--we can open it up & fold it out. But my philosophy on a truly superb job is that almost all of the equipment remains hidden. Keep it subtle & low-key. Only crank it way up now & then. You don't have to max the volume every time you hear a bass rumble at a stoplight from some idiot who wouldn't recognize good music if it crashed through his windshield. The louder you play your music right where everybody knows you park your car for extended periods, the more lights & doodads & manufacturer's stickers you plaster all over your vehicle, the more you're begging someone to take it away.


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## captain_shrapnel (Sep 10, 2004)

I'm with sr20demon and punkrocka as well. Caps are a waste. Quality amp manufacturers understand 
1. The issues with a 12 DC car electrical system.
2. How to build capacitance to overcome this issue right into the power supply of the equipment they build.

Makes sense, right? The big 3 and the yellow top are where its at.


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## ahardb0dy (Nov 9, 2003)

Recent quote on high output alt. for my 90 sentra ( prob. the same for other years) from Wrangler northwest power products, "The first alternator kit is a 150 amp Hitachi replacement that looks a lot
like what is in you vehicle now, that kit is $680.00. Another kit retrofits
a GM style alternator with brackets to fit in you Nissan, this quote is for
a 135 amp alternator with all the brackets & adapter harness for $375.00." . I had a 160 amp. dual output, external regulator alt. from wrangler years ago in my 87 nissan 4x4 pickup, never had any problems with it, paid about $450 for everything ( my dealer cost back than). Both are expensive to me can the factory alt. be redone to put out a decent amount of amps?


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## 92 Sinatra (Jul 9, 2002)

*Wow! Those alternators are expensive!*



ahardb0dy said:


> Recent quote on high output alt. for my 90 sentra ( prob. the same for other years) from Wrangler northwest power products, "The first alternator kit is a 150 amp Hitachi replacement that looks a lot
> like what is in you vehicle now, that kit is $680.00. Another kit retrofits
> a GM style alternator with brackets to fit in you Nissan, this quote is for
> a 135 amp alternator with all the brackets & adapter harness for $375.00." . I had a 160 amp. dual output, external regulator alt. from wrangler years ago in my 87 nissan 4x4 pickup, never had any problems with it, paid about $450 for everything ( my dealer cost back than). Both are expensive to me can the factory alt. be redone to put out a decent amount of amps?


Much more so than I had anticipated. Given that, I may hook the sucker up & see how it goes.

There are decent local alternator shops that have been in business for 50+ years. If I need to upgrade, I might just talk with them & see what we could arrange. This cannot be THAT compicated. Also if I have it done locally, if anything seems at all remiss I can talk it over with them.


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## Nismo240 (Jul 24, 2004)

u need a capacitor. get a rockford fosgate, they're really good.


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## captain_shrapnel (Sep 10, 2004)

No, he doesn't.


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## Jasper (Apr 2, 2004)

FOR CHRIST SAKES PEOPLE THIS IS WHY MY THREAD NEEDS TO BE STICKIED

http://www.nissanforums.com/showthread.php?t=79825

READ AND LEARN

BAH!


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## Nismo1997 (Dec 26, 2003)

I got a 2.4far. and paid 87$ shipped to my door


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