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My car is suffering from a 650w amp and 1 12" sub!!
http://www.teamswift.net/viewtopic.php?f=13&t=35437
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Author:  99metrodrifter [ Mon Dec 24, 2007 1:27 pm ]
Post subject:  My car is suffering from a 650w amp and 1 12" sub!!

well, I just finished putting my system together. Im using a kenwood cd deck, 200w total, running the factory speakers on deck power, and I picked up a nice amp on craigslist the other day (a boss 650w 2ch) and I have my 12" kenwood 1200w sub bridged onto it. not even 1000w for everything together.

nothing excessive right?? but for some reason its killing my 99 3 banger. whenever the bass hits hard, the headlights dim... bad. like, to half their brightness. also when I look at my tach I can see the idle fall off when the bass hits. Ive been in cars with much more monstrous systems and it wont take their idle down!?!? my pal said I should run a jumper wire directly from the bolt on the case of the amp to the (-) side of the battery to help with that. how would this help and what else can I do? :?:

Author:  m [ Mon Dec 24, 2007 5:06 pm ]
Post subject: 

Look in the stereo FAQ section for the "Big 3". Are the gains on the amp maxed out as well? What gauge wiring is holding everything together?

Author:  99metrodrifter [ Mon Jan 07, 2008 3:24 pm ]
Post subject: 

no the gains on the amp are set to center. I'm not sure what gauge wire I have for my power and ground, I have to look again, but Ive seen thicker. from the amp to the sub is 14 gauge.

my battery was in horrible condition (got really hot durring use, never started the car after sitting overnight, and was spewing acid when I pulled it out to swap it) :shock: and replacing it helped somewhat. the "big 3" thats the alt. ground, chassis ground, and what else?

Author:  swift13b [ Mon Jan 07, 2008 4:41 pm ]
Post subject: 

I always upgrade the hot wire off the alternator. I leave the stock grounds as is (unless they are bad) and add a thick one from engine to chassis, then a thick one from chassis to neg battery (usually at the same spot if I can do it) and then a thick one going from the pos terminal to the fuse box/etc. I typically use 4awg when I do this

Author:  blacksprint [ Mon Mar 24, 2008 2:45 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

I think it's time for a capicator. that would help a lot. It did for me anyway. just my .02

Author:  m [ Mon Mar 24, 2008 5:21 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

Definetly not time for a capacitor. Capacitors are a band aid fix that do more harm than good.

Author:  Darrell [ Tue Mar 25, 2008 1:46 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

m wrote:
Definetly not time for a capacitor. Capacitors are a band aid fix that do more harm than good.


Please explain.

I've never heard that.

I've always heard of these....

-bigger alternator
-bigger battery/more batteries
-capacitor
-bigger wires/less resistance/better connectors

Author:  m [ Tue Mar 25, 2008 9:44 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

viewtopic.php?p=54856#54856



I'll try to find a working link to Richard Clark's test as it seems to be broken.

Author:  m [ Tue Mar 25, 2008 9:47 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

If I was to put things in a particular order it would go like this:


-Big 3 upgrade
-Good battery. That just means a properly functioning battery
-Better alternator
-Capacitor...if your worried abhout looking pretty

Author:  Darrell [ Tue Mar 25, 2008 11:20 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

That link makes sense. Capacitors do help, but we need to understand how or when. When sustained current is required from it must be from an alternator and we can't expect a capacitor to do the job. For example, a capacitor might be able to support an amp with an occasional hit from a woofer, but it might not be able to support thundering fast beats because the capacitor might not be charged yet.

So I wouldn't say capacitors are bad or that they do harm. Better amplifiers will have large caps in them already.

Author:  m [ Tue Mar 25, 2008 11:25 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

They don't do any harm when they are used as intended. The problem is that you go to future shop and buy a 1000W system and they sell you a capacitor at the same time. The capacitor is added before any other electrical issues are addressed and that when they do harm. The alternator is already suffering and you add another load to the system to make its job even harder. You could argue that even after you add an upgraded alternator that capacitors are pretty much useless as the amplifiers have the proper capacitance on board to properly handle current demands. The Richard clark link actualy shows a decrease in voltage to the amplifier when the capacitor was in use. That was also partialy attributed to the resistance the capacitor added to the power line.

Author:  Darrell [ Tue Mar 25, 2008 1:14 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

I wonder about the capacitor that was used in the setup. Capacitors are supposed to have infinite resistance once they are charged (yes there's always some leakage). Sometimes caps can have stupid voltmenters attached to them that don't have infinite resistance.

Also, you won't get a higher voltage with a cap. You'll only get a smoother voltage. The voltage will only be as high as the voltage that supplies it...or lower when it's filtering....but the lows won't be as low either. A slightly lower average voltage would expected if the capacitor is discharging and charging. Remember voltage is not power. It's important to consider voltage and current at times. equation: volts x amps = power

A capacitor should not be considered as a load if it's working properly or if it's a good cap. If a capacitor installation causes an increase in system current then either cap is bad or it is truly helping. For example the capacitor might be helping to supply current during the peaks when before the alternator is saturated or maxed out.

Anyway....I would say caps are good as long as it's of good quality and it's used right.

Author:  m [ Tue Mar 25, 2008 4:51 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

I didn't mean to say you would get higher voltage with a cap. The voltage drop to the amplifier was higher (lost more voltage) with the capacitor installed. It was a 5F cap IIRC and the voltage drop was around a volt lower with the capacitor connected. What is interesting about the testing is that Richard Clark and Dave Navone are the original creators of stiffening capacitors for autosound use so one would think that they wouldn't be making them look bad.

A capacitor will most definetly present itself as a load because it needs to be charged.

A 1F cap gives you 75W more juice for one second...750W for a 10th. Its not supplying nearly enough current to offset the power demands of a large amp. Even with a larger 5F cap you hit a wall pretty fast. If they were supplying any decent amount of current you would see world class SPL vehicles running them. I can think of a few...and they have over 500F of capacitance by using large 100F caps...and they weren't sitting on the #1 podium.

Author:  Darrell [ Tue Mar 25, 2008 5:38 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

Yeah a cap does need to charged initially, but when it's in use it shouldn't be considered a load...it's like a filter.

Caps aren't not meant to supply power that's true. It's only supposed to smoothen the voltage ripple or dips in voltage.

I'm off to work! :arrow:

Author:  m [ Tue Mar 25, 2008 6:13 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

Darrell wrote:
Yeah a cap does need to charged initially, but when it's in use it shouldn't be considered a load...it's like a filter.

Caps aren't not meant to supply power that's true. It's only supposed to smoothen the voltage ripple or dips in voltage.

I'm off to work! :arrow:




Darrell wrote:
Yeah a cap does need to charged initially, but when it's in use it shouldn't be considered a load...it's like a filter.

Caps aren't not meant to supply power that's true. It's only supposed to smoothen the voltage ripple or dips in voltage.

I'm off to work! :arrow:




I see what your saying and I agree...assuming that the alternator is always able to fully supply the current needed by the system. I tend to argue the voltage loss/supply of capacitors because this is what people think they are for. This is my problem with capacitors. They are, as you say, designed to smooth out voltage ripples. They are, unfortunately, marketed as a storage container waiting at a moments notice to dump current into your amps when the alternator can't keep up. People buy into this and throw them on a car that is having voltage issues to begin with (hey it cures headlight dimming) thinking it will solve all their problems. This is why the cap becomes a load when it isn't supposed to...it keeps getting drained and charged to try and help an ailing electrical system. In a perfect world everybody would install their system, better wiring, a bigger alternator, and then a cap if they felt it helped the sound.


To the OP. Sorry for the tangent in your thread. Have you had any luck with replacing the wiring in your car? There is a how to in the stereo FAQ section (its stickied near the top of the stereo section) that will show you where the wires are supposed to go.

Author:  wanderingelf [ Tue Mar 25, 2008 6:16 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

At 650 w you should really not notice much of a power drop in the cars electronics when the sub "hits". I noticed a lot of talk about caps in the forum. A word of caution though, caps are notorious for "killing" alternators and amps for "eating" batteries. Yes they can help balance power draw spikes. But have you tried upgrading your ground wire from the battery to the chassis as well with the ground from the amp? Use the chassis for the ground at the amp, you will get less harmonic distortion. Also ground it away from other components. I use 4 gauge welding cable instead of the stock battery wires. Also consider the engine ground to the chassis, I seem to remember that the stock wire is along the lines of pathetic and considering that it is actually the wire from witch the alternator grounds to the car via the engine block on witch it is bolted it is important. I did not have to add a cap to my setup until after a thousand plus watt class d amp. Remember that no matter how big your positive power wires are, they will be next to useless if the system is not grounded with equal or greater wires, the main chassis ground at the battery being most important, more so than the positive lead from the alternator. I run nearly 2000 watts of combined system power and auxiliary road lights with no noticeable dimming of my lights, the secret is in the ground!

Author:  Darrell [ Wed Mar 26, 2008 3:12 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

There's the cool factor too. The other guy has a cap so I want one too. :)

I wanted to point out one thing. People think replacement alternaters will give good power all the time but they won't. The current rating is sometimes delivered when the alternator is spinning at 5000 rpms...not at idle. So if you upgrade the alternator make sure you look at all the specs before you buy. :buzz: <---Stereo is on!

Author:  m [ Wed Mar 26, 2008 10:32 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

Darrell wrote:
I wanted to point out one thing. People think replacement alternaters will give good power all the time but they won't. The current rating is sometimes delivered when the alternator is spinning at 5000 rpms...not at idle. So if you upgrade the alternator make sure you look at all the specs before you buy. :buzz: <---Stereo is on!



Very true. Idle output is sometimes much less than the factory units.

Author:  swift13b [ Sun Apr 20, 2008 3:40 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

as for capacitors its only good to maintain a steadier voltage across the mosfets. the amp is made to work from like 11-16volts input but every time the bass hits it drops from say 14 to 13.. at 14volts you are drawing 46.5A to make your 650w but at 13volts you are drawing 50. A cap (if placed within a foot from your big amp) WILL help with the amount the voltage fluctuates but it doesnt really act as a reserve for power. even 3farad caps dont do much. capacitors arent useless

Author:  m [ Sun Apr 20, 2008 4:17 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

swift13b wrote:
capacitors arent useless



They are when they are being used to stop voltage drop. Unfortunately they are marketed as devices which are used to do this. They are designed (as you have said) to steady the voltage...not easy in a car where the factory alternator supplies less power than what the system demands.

Author:  swift13b [ Mon Apr 21, 2008 2:20 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

yeah, sorry should have clarified that. but look at the numbers I gave, 650w is going to grab you 50amps at 13V, I dont understand how people put huge systems 1500+watts in their tiny cars and brag about it thinkin they are actually getting that much. Anytime ive gone over 800W ive had a second battery, but ive never done big stereos in a car this small, with this little charging power, yet. im doing a wild carputer setup with 4 10's and 2 good component sets up front with a whole bunch of amp. so we'll see how that turns out (atleast ill have 180whp to generate it)

but as for alternators im a little blurry at this point as for loading the engine, ill try to make this simple hopefully someone can answer.

ok lets say your alternator is rated for 50amps. thats 50amps at like.... 2000rpm or so, it does not generate max charging power at idle. youve *probably* (guessing here) have a max of 25-30amps at idle, so no wonder this persons system is suffering, your running lights and a bunch of other stuff (engine accessories) so we'll say you are drawing 10amps running the car (guessing again) leaving you with 15-20amps available at idle which is a maximum of 288watts if you have a healthy charging system and maintaining 14.4volts... which you wont, youll be sitting around 12 at this point if you have the system loaded, leaving you 180-200watts to throw at your stereo. Which is CLEARLY not enough.

Ok but how much horsepower does generating a full 50amps take? on full load I wouldnt be surprised if it takes 5-7.5hp away just to charge up the system, plus it loads the engine and reduces acceleration. But how much hp would it take at idle with just a regular engine load? 1hp? tops?

Im wondering if you can get bigger, more efficient alternators... I bet the charging output of the alt isnt totally linear, and it has a "suggested rpm range" for efficiency like a turbo charger, but its designed to go through all the rpms of the car. Putting a huge 100A alternator on your car probably isnt going to solve everything though. you load that thing up at idle and itll take enough idle horsepower away that it could probably kill the engine too.

these cars suck for stereos lol, dinky little tin can with a "gas generator" to power the electronics lol. you need power and electricity to put more than like 300watts into a stereo system in this car, reliably. im a big stereo buff so I usually only do things the right way.

we'll see what I come up with for this carputer project.

Author:  Darrell [ Mon Apr 21, 2008 6:32 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

I think you're asking all the right questions. I put out the comment about the alternator, but I really don't know anything else. I've never heard of anybody having an alternator that was more of a load than the AC. So you might be ok with a bigger alternator.

Keep asking questions and let us know too.

:)

Author:  m [ Fri Apr 25, 2008 1:58 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

Bigger alternators will definetly put a bigger load on the engine but only in proportion to what is being drawn from the alternator. As far as how much power you could lose I really can't say but the alt specialist I went to had a 30hp motor to turn the big 200A+ units during testing. I doubt it needed the full 30hp but he had a 15hp rig for the smaller ones so the big ones definetly needed a good amount more power to turn them.

As far as putting a huge system in these cars and not getting full power it depends on a few things. I think the key (other than replacing the alternator) is making the wiring as "lossless" as possible. Upgrading all the power and ground cables are a huge help in this regard. Getting a really good battery (not necessarily multiple ones) also makes a big difference. Try to get something that betters 800A. There is room for a full size GM alternator to fit in place of the AC system. Obviously you have to remove the AC for this option. Factory location is harder to fit anything because it is quite cramped. Getting the factory alt rewound won't give you anything because there is little to no room in the case to add more windings. There are rumours that Bosch makes a 90A replacement alt for these cars but I don't think it was ever confirmed. I have also heard of, but not seen, making brackets and fitting a larger alternator in the factory spot. I know its been done in a MKI so I suppose its possible for a MKII. I was going to go the dual alt route so I never really looked into it too hard. I know there were a few threads on this topic so if you search you may find more info about it.

Author:  Justintoxicated [ Fri May 30, 2008 4:00 pm ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

I think you should feel lucky, my headlights dim when I turn the heater on! 1000 watts of power is quite a bit of juice, Even in my V8 5.6L truck going beyond 1500 watts means larger alternator, and you don't want to turn it up at idle like that unless you have an oversized or multiple batteries.

You could also look into more efficient headlights, like HID's etc. Anything to keep the electrical draw down.

Author:  Justintoxicated [ Tue Jun 10, 2008 4:26 am ]
Post subject:  Re: My car is suffering from a 650w amp and 1 12" sub!!

m wrote:
They don't do any harm when they are used as intended. The problem is that you go to future shop and buy a 1000W system and they sell you a capacitor at the same time. The capacitor is added before any other electrical issues are addressed and that when they do harm. The alternator is already suffering and you add another load to the system to make its job even harder. You could argue that even after you add an upgraded alternator that capacitors are pretty much useless as the amplifiers have the proper capacitance on board to properly handle current demands. The Richard clark link actualy shows a decrease in voltage to the amplifier when the capacitor was in use. That was also partialy attributed to the resistance the capacitor added to the power line.


Right on Caps are only needed to help provide a faster burst of power on really high power systems. Using it to slove headlight dimming is putting more strain on your alternator, cause after 1 second the alternator is discharged then the alt has to charge back/power both the battery, amp AND the Cap. Just more strain on your system but it can help cure the headlight dimming voltage flux. I have always wondered if it would be better to run the cap on the headlight circuit rather than the amp (assuming the wire could handle the current).

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