Best way to fix sub voltage drops

[ScaryFatKidGT]

So I got 2 13.5" JL W3v3's with a Alpine MRP-M1000 and there awesome but as I turn it up I'm getting some serious light dimming going on. Now I know the obvious way to fix this is a capacitor but I know nothing about them and it seems to just be putting off the problem, in really bass heavy music wouldn't it just over work the capacitor and it would be like it wasn't even there? I have a new battery, would a BIG 3 wire kit or grounding kit help? or would I need a bigger alternator?

If I get a capacitor what should I get? I want good sound quality, thats why I got JL subs and a sealed box.

And do I need to be worried about toasting my battery or frying anything drawing this much power?

[Wiscon_Mark]

I would upgrade your battery to an Optima Yellow top. They're made for high powered sound systems and other high draw electrical devices on a car. Expensive, but much better than a standard battery anyways.

The other thing you should look into is a better alternator that puts out more charging current. If your lights are constantly getting dimmer, your alternator likely can't keep up.

A capacitor is still a good idea. Basically a capacitor is a temporary storage unit for electricity. When you get spikes in power draw (ie: bass drum), it'll feed that extra current need a charge back up when the power flow is lower. I don't know a whole lot about which capacitors are good though - best thing to do is go on Crutchfield or SonicElectronix and read lots of reviews.

[ScaryFatKidGT]

Any one else? I'm guna get the big 3 kit and see if that helps at all. Who sells alt's? I remember people talking about using an STi alt but I think the conclusion was that is was only like 5amps more and wasn't worth the time.

When the car is running every thing basically runs off the alt right not the battery?

[Matty2Hotty]

This places is the most popular for alternators

http://www.maniacelectricmotors.com/hioual.html

[ScaryFatKidGT]

Hmmm how come the one for legacy's is the most expencive? Arn't all legacy, impreza and forester ones the same? Stock is like 115 amp right?

How do yellow tops compare in weight to normal batteries?

[chuckthefuk]

That setup will kill your batt/alternator. Lots of wattage.. lots of current draw..

In order of installation of prevention:
- Optima Battery
- Thicker wires
- Capacitor
- Alternator


Battery info:
Average Battery = 15-18 lbs
Red top = Average weight = 30 lbs (http://www.optimabatteries.com/optima_p ... /specs.php)
Yellow top = Average weight = 36 lbs (http://www.optimabatteries.com/optima_p ... /specs.php)
Optima batteries are DRY CELL so no liquid battery acid..
-Mount in any orientation
-DRY CELL = Service-less
-Higher cold cranking amps

Alternator info:
90% of Subaru alternators are interchangeable.
The reason this is not a popular mod is because the wiring changed from 2 pin to 3 or more...
You can find a LOCAL alternator re-builder shop who can spin a larger coil for you in your stock casing. This will give you a higher amp output.

Charging info:
- The vehicle runs off both alternator and battery.
- Battery starts the car.. feeds the electronics
- Alternator produces more then 12v and feeds into the battery.
- When your alternator is dead the motor will turn over run and then when turned off will not crank over again..
- Opposite would be battery dead alternator working.. bump start and alternator runs the car... yay.

Capacitor info:
- Capacitors are the ONLY form of power device longevity.
- Capacitors sole function is to reduce load on the power circuit.
- Capacitors are not long term batteries.. they are short term.. they get filled and drained within seconds.
- By adding capacitor(s) to your setup as the amplifier draws large amount of power they will take it from the capacitor first at the same time giving the charge system enough time to fill the capacitors.
- Using caps will stabilize your power draw. Watch your volt meter with / without the cap. Without = 9v ~ 12.4~ . With = 12~13v
- If your power draw is still to quiet large then you can add multiple caps in series to increase charge/release cycle.

Wiring info:
- Larger gauge positive wiring allows for a larger current draw.. or higher amps to be passed through without the possibility of melting the wire.
- Larger gauge ground wires with a proper grounding spot (paint removal and pure metal contact) will remove noise.
- Shielded RCA wires will increase sound quality if the RCA's are running parallel with the power wires.

- Chuck

[ScaryFatKidGT]

That setup will kill your batt/alternator. Lots of wattage.. lots of current draw..

In order of installation of prevention:
- Optima Battery
- Thicker wires
- Capacitor
- Alternator


Battery info:
Average Battery = 15-18 lbs
Red top = Average weight = 30 lbs (http://www.optimabatteries.com/optima_p ... /specs.php)
Yellow top = Average weight = 36 lbs (http://www.optimabatteries.com/optima_p ... /specs.php)
Optima batteries are DRY CELL so no liquid battery acid..
-Mount in any orientation
-DRY CELL = Service-less
-Higher cold cranking amps

Well my interstate is over 30lbs I think. I would like to go lighter than heavier if posable. Would the lightweight batteries from Tirerack work? Both the the 17 and 21lbs batteries say for extreme audio builds.

Alternator info:
90% of Subaru alternators are interchangeable.
The reason this is not a popular mod is because the wiring changed from 2 pin to 3 or more...
You can find a LOCAL alternator re-builder shop who can spin a larger coil for you in your stock casing. This will give you a higher amp output.

Can you expand on the 2 pin 3 pin thing or how to get a new one? Il look in to the local re-build I know a place.

b]Charging info:[/b]
- The vehicle runs off both alternator and battery.
- Battery starts the car.. feeds the electronics
- Alternator produces more then 12v and feeds into the battery.
- When your alternator is dead the motor will turn over run and then when turned off will not crank over again..
- Opposite would be battery dead alternator working.. bump start and alternator runs the car... yay.

b]Capacitor info:[/b]
- Capacitors are the ONLY form of power device longevity.
- Capacitors sole function is to reduce load on the power circuit.
- Capacitors are not long term batteries.. they are short term.. they get filled and drained within seconds.
- By adding capacitor(s) to your setup as the amplifier draws large amount of power they will take it from the capacitor first at the same time giving the charge system enough time to fill the capacitors.
- Using caps will stabilize your power draw. Watch your volt meter with / without the cap. Without = 9v ~ 12.4~ . With = 12~13v
- If your power draw is still to quiet large then you can add multiple caps in series to increase charge/release cycle.

So a cap is a really good idea? I was just wondering if they will stand up to Dubstep or Dragonforce lol. Do you know of any good ones? I'm guessing the more they can hold the better.

b]Wiring info:[/b]
- Larger gauge positive wiring allows for a larger current draw.. or higher amps to be passed through without the possibility of melting the wire.
- Larger gauge ground wires with a proper grounding spot (paint removal and pure metal contact) will remove noise.
- Shielded RCA wires will increase sound quality if the RCA's are running parallel with the power wires.

- Chuck

I have 4gau for the amp which I think is good for over 2000watts.

[Wiscon_Mark]

If you're looking for weight savings, don't do it with your battery. I'm sure that amp and sub combo weighs a lot more than the difference between a lightweight & a standard battery. FWIW, I'd say my Everstart battery is a lot closer to an Optima than a standard by Chuck's estimates.

Bottom line is - if you want audio performance, you shouldn't skimp on the driving components. 4 gauge wire should be sufficient. A capacitor is better than no capacitor.

[ScaryFatKidGT]

If you're looking for weight savings, don't do it with your battery. I'm sure that amp and sub combo weighs a lot more than the difference between a lightweight & a standard battery. FWIW, I'd say my Everstart battery is a lot closer to an Optima than a standard by Chuck's estimates.

Exactly why I want to save weight lol.

Bottom line is - if you want audio performance, you shouldn't skimp on the driving components. 4 gauge wire should be sufficient. A capacitor is better than no capacitor.

Darn. I would of though a battery thats 2x the money and 2/3 the weight would perform better being drycell and all.

[chuckthefuk]

1) The weight of the battery should not be something to think about unless your looking for weight distribution. . DRYCELL tech is a major upgrade over the liquid types when running any type of sound system.

2) Alternator conversion.. http://bbs.legacycentral.org/viewtopic.php?f=19&t=18135

3) Yes it is a good idea. Test this theory and buy a voltmeter gauge and watch how your voltage drops and besides, you should always have a voltmeter!

4) The fact that you have 2 x 13.5" woofers is half way correct:
6-10" = rock, house, jungle, breakbeat
12+" = hip-hop, rap, down temp

The faster the beat the faster the diaphragm has to move in/out..

Dubstep is a combination of fast and slow. So to ask a 13.5" woofer to operate during the fast lows is going to be iffy.

5) 4-AWG works... but if you think your amp can take more upgrade the size

[ScaryFatKidGT]

1) The weight of the battery should not be something to think about unless your looking for weight distribution. . DRYCELL tech is a major upgrade over the liquid types when running any type of sound system.

http://www.braillebattery.com/index.php/batteries/b3121/# This has almost the same specks as a yellow top for amp output. It's not so much the front to rear distribution as it is center to ends. The batteries are a big heavy weight and in are cars sit way out in front of the engine and tires, but relocating it would just add more weight.

2) Alternator conversion.. http://bbs.legacycentral.org/viewtopic.php?f=19&t=18135

3) Yes it is a good idea. Test this theory and buy a voltmeter gauge and watch how your voltage drops and besides, you should always have a voltmeter!

) The fact that you have 2 x 13.5" woofers is half way correct:
6-10" = rock, house, jungle, breakbeat
12+" = hip-hop, rap, down temp

The faster the beat the faster the diaphragm has to move in/out..

Dubstep is a combination of fast and slow. So to ask a 13.5" woofer to operate during the fast lows is going to be iffy.

Not to say your wrong, and I am defending my purchase some what but I feel like that is a very broad, generalized recommendation. There fairly spendy sound quality oriented subs and I have them in a sealed box with more than enough power to drive them effectively. The main reason I got the 13's was because they where $70 less the the 10's and $130 less than the 12's and the 10's and 12's are 500 watts apiece where the 13's go up to 600 (I'm planning to get a 1200-1500 watt amp in the distant future) and because I want the lower frequency response.

) 4-AWG works... but if you think your amp can take more upgrade the size

And I think 4 is good my weak spot now is my before the wire get to the amp.

[chuckthefuk]

1) I agree with the weight placement however you're not thinking about the whole picture.

a) Relocating the battery to the trunk will only add 6 lbs (wiring & battery box) similar to BMW's weight method

b) Installing a light weight battery in the stock location will yield few results and more issues down the road

c) Read this for more info about light weight battery choices if you must -> http://forums.nasioc.com/forums/showthr ... ?t=1852892
"..From the research I have done, you are going to be safe with an Optima yellow top. If you want to get extreme, some of the lightweight batteries like Oddesy, Deka, Braille, etc are great. They tend to have more problems with long term reliability, complete discharge recovery, and cold starts. Take this into consideration. Especially if your in a colder climate..." -roninsoldier83

3) My generalization sums up the basics of diaphragm response/movement and the general genres that respond better/worse to them. Not to knock your setup but there is a reason why the 13.5" woofers are under priced and can be driven harder. If your looking for the lower frequency response's then you have the proper setup, I am just point out that they will not run efficiently compared to smaller woofers. This is the reason why the pros use multiple sizes instead of just **" twins. Its your setup do what you want just take this with a grain of salt..

Cheers & good luck with your voltage issues.. I am off to finish the T-shirts..
-Chuck

[ScaryFatKidGT]

1) I agree with the weight placement however you're not thinking about the whole picture.

a) Relocating the battery to the trunk will only add 6 lbs (wiring & battery box) similar to BMW's weight method

b) Installing a light weight battery in the stock location will yield few results and more issues down the road

c) Read this for more info about light weight battery choices if you must -> http://forums.nasioc.com/forums/showthr ... ?t=1852892
"..From the research I have done, you are going to be safe with an Optima yellow top. If you want to get extreme, some of the lightweight batteries like Oddesy, Deka, Braille, etc are great. They tend to have more problems with long term reliability, complete discharge recovery, and cold starts. Take this into consideration. Especially if your in a colder climate..." -roninsoldier83

3) My generalization sums up the basics of diaphragm response/movement and the general genres that respond better/worse to them. Not to knock your setup but there is a reason why the 13.5" woofers are under priced and can be driven harder. If your looking for the lower frequency response's then you have the proper setup, I am just point out that they will not run efficiently compared to smaller woofers. This is the reason why the pros use multiple sizes instead of just **" twins. Its your setup do what you want just take this with a grain of salt..

Cheers & good luck with your voltage issues.. I am off to finish the T-shirts..
-Chuck

The 13" were on sale and they were originally more and I think I would need 3 12's of the same type to match the air these move.

But anyway thank you for that thread the beginning was helpfull but all it really told me was to not buy Braille's but now idk what to get... there is to much flaming and arguing for me to read it all.

And I'm really fucking pissed because I was looking at caps reading reviews on crutchfield and I contacted them and they said a 2 farad cap would be what I needed and that if my lights still dimmed then I would need a better battery but he was pretty sure the 2 farad cap would be all I needed.
So today I went to the place that installed my stuff, the only local shop I know of, and asked about caps and he said they don't sell them because it's only putting a band-aid on the problem and that I would need to add another battery and showed me some batteries that were half the size of my interstate and weight more WTF! why are places so stupid do they think EVERYONE is a fool? I got my subs offline cuz this shop told me that a ported box is the only way to go and that the only reason for a sealed box was to save space. I wonder if they even installed my shit right? My amp is probably grounded to a piece of wood or something gaaaaa.

And BTW I really hate that uncle scotty guy on nasioc

[Wiscon_Mark]

And BTW I really hate that uncle scotty guy on nasioc

As for your ported vs. sealed box.

Ported:
Pros - takes less power to drive speakers because of easier airflow, boomier bass
Cons - boomier bass, less controlled sound

Sealed: Vice Versa from ported - sound quality is more the goal, with bass being more controlled and tight.

Of course every amp/sub/box have their own characteristics, so keep that in mind, but sealed boxes are certainly not just for saving space. There's a lot more to the shape and design of a box than space...

The guy at the shop wasn't wrong - a capacitor is just a bandaid if a system is running more juice than the battery & alternator can put out. I'm guessing he didn't ask you about that stuff and just dismissed you as a dumb kid. I really hate it when people do that. Some a-hole at Advance Auto told me if I went with a hotter spark, I'd burn my piston rings out. I didn't even bother arguing with him. Context is everything.

[ScaryFatKidGT]

And BTW I really hate that uncle scotty guy on nasioc

Seriously someone needs to put him in his place. I asked a question about summer tires and he said that I had already asked 1000 times and If I couldn't make a decision that I should sell my car and buy a moped or something and it was the first time I had posted on Nasioc in months so I sent him a PM asking wtf his problem was or if he thought I was someone else and he never responded. Seriously read that battery thread its hilarious in a painful way.

As for your ported vs. sealed box.

Ported:
Pros - takes less power to drive speakers because of easier airflow, boomier bass
Cons - boomier bass, less controlled sound

Sealed: Vice Versa from ported - sound quality is more the goal, with bass being more controlled and tight.

Of course every amp/sub/box have their own characteristics, so keep that in mind, but sealed boxes are certainly not just for saving space. There's a lot more to the shape and design of a box than space...

Of course every amp/sub/box have their own characteristics, so keep that in mind, but sealed boxes are certainly not just for saving space. There's a lot more to the shape and design of a box than space...

I know I know thats why I reseach on the internet instead of asking them anything and I didn't even talk to him about tuning the box if he is going to treat me like that. I want sound quality so I got 2 JL audios in a factory sealed box from crutchfield.

The guy at the shop wasn't wrong - a capacitor is just a bandaid if a system is running more juice than the battery & alternator can put out. I'm guessing he didn't ask you about that stuff and just dismissed you as a dumb kid. I really hate it when people do that. Some a-hole at Advance Auto told me if I went with a hotter spark, I'd burn my piston rings out. I didn't even bother arguing with him. Context is everything.

This was a different guy. He said what I originally thought, that the capacitor is only for short use and that a long bass note would use it all up and he eventually asked how many watts RMS I was using, but then he said that even if I got a 10 farad cap it wouldn't be enough and that I need another battery and a bunch of B.S. about how I want to stabilize my voltage (I FUCKING KNOW THATS WHY I"M ASKING ABOUT CAPS!). I only have 1 1000watt amp not 5000watts I THINK 5 Farads would be more than enough to hold enough juice for just about everything but idk. And he said all I would need is a better battery and my light dimming would go away but I told him mine wasn't even a year old so he said I could add another. Now tell me how is just replacing my stock battery (no alt mods and no cap) going to fix everything?

I really hate having to become a expert on every thing just to solve a problem (I'd say I am not an expert on tires, wheels that fit this car, subaru exhaust mods, headphones, flashlights and a bunch of other stuff) Every time the guy at discount tire tells me that 17" tires only come in summer and winter and ones that say "All-Season" are really just the same as summers I wanna kill myself. He also told me no summer tires carry any tread wear warranty.

Anyway there is a right way to fix this I just wish someone would tell me but I'm not adding a second lead brick to my car (if the alt isn't putting out enough wouldn't 10 extra batteries all eventually go dead?) and I have been looking at lightweight batteries for a while and sense all lightweight batteries are dry sell they would be an upgrade from stock if I could find the right one. I'm not talking real light just like 20lbs instead of 40 thats like talking a 20lbs dumb bell of from your car and would add to my lightweight pulleys for weight off the front end.

Unfortunately in the world of sound Heaver=Better

[chuckthefuk]

Seriously man...

Buy a Red Top.
Get a re-wound alternator from a local rebuilder.
Then look at your voltage issues.

Your causing yourself massive amounts of stress.. Its the real world.. if you don't want to be taken advantage become and pseudo expert.. "its the way she goes"

Take the few extra pounds and consider the pro's of having a battery that is actually able to be constantly drained without consequence.

P.S.. its NASIOC.. deal with it.. but I officially gave up on Uncle Scottie when the truth about this miracle cocktail surfaced :smt012 .

[ScaryFatKidGT]

1) I agree with the weight placement however you're not thinking about the whole picture.

a) Relocating the battery to the trunk will only add 6 lbs (wiring & battery box) similar to BMW's weight method

b) Installing a light weight battery in the stock location will yield few results and more issues down the road

And I'm thinking of it like this.

Battery relocated=-35lbs up front +35 in back +6 over all (wiring)

Lightweight=-15lbs in front and -15 over all so a 21lbs difference in the one (-15 vs. +6)

So I will get about 1/3 the front to rear distribution advantage plus netting a weight loss.

[ScaryFatKidGT]

Seriously man...

Buy a Red Top.
Get a re-wound alternator from a local rebuilder.
Then look at your voltage issues.

You mean a yellow top? And no cap? And what are the pros/cons vs. a new lets say 140AMP alt and a Re-wound one?

Your causing yourself massive amounts of stress.. Its the real world.. if you don't want to be taken advantage become and pseudo expert.. "its the way she goes"

Yeah I have discovered this I just don't have time for every thing I'm interested in, I am also a pseudo expert on brake pads and fluid (rotors im still lost on).

Take the few extra pounds and consider the pro's of having a battery that is actually able to be constantly drained without consequence.

Yeah but lightweights can still be drained and recover. And I need more power when my car is running, I hardly ever listen to my stereo when the car is off thus deep draining the battery? My lights dim when the car is on

P.S.. its NASIOC.. deal with it.. but I officially gave up on Uncle Scottie when the truth about this miracle cocktail surfaced :smt012 .

Whats the story behind this? lol

[chuckthefuk]

0) Personal use has never needed yellow tops. Great Success with Red Tops.. Save some coin.
1) nothing... the rewound alt will be similar spec to the new higher amp alternator. Its just an easy way to save on money if the new alternator cost to much.
3) Your system will put a high load on your battery even when driving, thus the quick discharge/charge rate. Lighweight batteries are just not suitable for daily driving, high load, cold environments.
P.S) Scotties cocktail surfaced as a miracle cure for 5MT's with "issues"... down the road the 5MT's just failed.. it was a band-aid. There is a huge post on Nasioc by a "credible" 5MT rebuilder who broke down the reasons why 5MT's fail with and without the cocktail. I am lazy and don't want to source the article so lets just say that its hog wash.

[ScaryFatKidGT]

0) Personal use has never needed yellow tops. Great Success with Red Tops.. Save some coin.

What do you mean by that? Are you running a sound system?

1) nothing... the rewound alt will be similar spec to the new higher amp alternator. Its just an easy way to save on money if the new alternator cost to much.

So a re-wound atl will up it from 115amp to over 130amp? If so il do it.

3) Your system will put a high load on your battery even when driving, thus the quick discharge/charge rate. Lighweight batteries are just not suitable for daily driving, high load, cold environments.

The bigger ones (17-21lbs) say they are.

[chuckthefuk]

1) Sometimes but i have a handful of legacy friends who are running various configurations with red tops, stock rating rebuilt alternators and larger wiring. Some have grounding mods some have cap's. No matter what config the window regulators drain/dim the most.

2) Talk to your local rebuilder and he should be able to build to your spec.

3) True... but its apples and oranges at 21 vs 30 lbs...

[ScaryFatKidGT]

1) Sometimes but i have a handful of legacy friends who are running various configurations with red tops, stock rating rebuilt alternators and larger wiring. Some have grounding mods some have cap's. No matter what config the window regulators drain/dim the most.

2) Talk to your local rebuilder and he should be able to build to your spec.

3) True... but its apples and oranges at 21 vs 30 lbs...

Anybody running similar set ups to me? With all the contradicting stuff I have read I feel like I'm the first person to ever put a 1000watt amp in there car.

What are the ratings on the stock alts? I thought they were around 115amps but there probably only like 90 right?

Is paranoid fabrications 4awg BIG 3 kit enough? I read on a couple forums where they suggested 1/0awg. Whats stock?

[ScaryFatKidGT]

Along with my other questions what do you guys think of me getting the 26lbs D51 yellow top instead of the correct 36lbs D35? Its an inch taller but still should fit? The only thing I don't like is that it only has 450CCA's I think the 26lbs odyssey has more, but I have recently read that using a yellow top as ur main starting battery will fry it wtf? lol

Also Sears Diehard platinum batteries are AGM but I think they are just re-badged odysseys like stingers. A lot of people on nasioc say brailles are overpriced junk that lie about the output but they have a lot of racing endorsements the others don't.

[Wiscon_Mark]

but I have recently read that using a yellow top as ur main starting battery will fry it wtf? lol

Source?

[chuckthefuk]

Shinanagans!!

[ScaryFatKidGT]

A thread on Nasioc and a car audio forum said to use a red top up front and a yellow in the back cuz the yellow will get cooked in a year up front, but I'm not putting in another and the guy at batteries plus said that yellow tops will self discharge in like a month or 2 of no use and then not take a charge.

But the good news is that my local batteries plus can get odyssey's and they have there own brand of re-badged Dekas!

D51 yellow top-450CCA's and 26lbs
odyssey 925/extreme racing 35-380CCA's and 26LBS
The Deka 21lbs re-badge-400CCA's and 21.7lbs (Deka says 365CCA's and braille says 450)
My interstate has 550CCA's and is 34-35lbs


And these but there spendy but batteries plus quoted me about 10-15% less than what these say
http://shop.odysseybattery.com/products ... 0.0?pp=12&
http://shop.odysseybattery.com/products ... 0.0?pp=12&
http://shop.odysseybattery.com/products ... 0.0?pp=12&

I have had about 4 People on Nasioc tell me they run these for 2-3 years just fine but I want something bigger.
http://shop.odysseybattery.com/products ... 0.0?pp=12& I didn't know 220CCA's would start a car haha.

[ScaryFatKidGT]

http://forums.nasioc.com/forums/showthr ... ?t=1453095
A lot of "This is good, thats bad... thats good, this is bad" but what I have seen is A LOT of people are running P680's (that last link I posted) That makes me think running a P925 would be no problem but my safe side says to just get the 26lbs yellow top.

EDIT: I was thinking the 925 was lighter than the optima but there both 26lbs so I just get the optima, but that Extreme Racing 30 and 40 are tempting but sure are spendy.

[Perdue]

I would advise against the capacitor...they are simply a bandaid, if that. I would find a place for a second battery. They make some smaller ones that you could mount just about anywhere.

[ScaryFatKidGT]

Will a yellow top help my lights from dimming at idle or will they allway dimm as long as the alt can't keep up because the battery is only 12 volts?

[Perdue]

I'm no car audio expert, but it looks like you are running a ton of wattage...mine barely dimmed with 400rms, but that was fixed with a red top. It still dimmed with a redtop and 800rms. I would recommend a second battery.