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What do capacitors do?

Phreddy

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No need to Morg! ;)

You're exactly right - a capacitor (well, in that particular application) functions as a storage vessel. Not unlike a battery in a way, except that it can release the stored charge much more quickly than any battery possibly could. However, it WON'T allow you to run the system with the engine off for any longer than you would without the cap.

You see, the capacitor receives its charge from the battery in the first place. When the amp makes a huge current demand spike (like a bass kick or summink) the capacitor can dump that charge into the amp in a couple of microseconds if needed, and recharges (again, from the battery) during the time in between the first instant and the next bass kick that comes along.

But they certainly don't "make their own power", or come anywhere near working as a reserve battery as such. A typical 1.5V AA cell actually holds more energy that your 1 Farad cap, but as mentioned before cannot deliver that energy in a single "belt" - there are physical and electrical characteristics within batteries which limit the peak current that can be pulled from them - limitations that capacitors don't suffer from.

Hope it's a bit clearer....

Cheerz!
 

Cameron

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i was looking to put a dd 9910 dual voice coil sub with two high end 1000watt mono block amps bridged or one into each voice coil, (not for competion, but i always got to buy the most expensive stuff) would i need to include a cap or would i need two, one for each amp, and what type of secondary battery brand would be recomended for such a system?
 

Phreddy

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Hey Cameron.

I'll handball this one to you King - I can dribble all day about the theory of capacitors, but have never really used them in car audio, apart from crossover networks.

From what I've picked up though, I'd be inclined to use a cap for each amp. But that might be incorrect! :whistling

Cheerz!
 

Tasmaniak

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*goes for the mark and drops it as per usual*

Hey Cameron. As a typical rule of thumb you use 1 Farad per 1000Wrms. You whack it the MAIN power cable before the splitter that power each amp so you only need one. I like to put them as close to the amps as possible, that way the extra boost isn't lost down a long length of cable.

As for the second battery, anything with a high CCA (Cold Cranking Amps) Some people will argue deep cycle and others will argue starter batteries. I prefer to use start batteries as they are designed for taking a big hit of power out of them at any given time e.g. starter motor. This also brings your costs down as well. The main advantage of deep cycle is that they are generally whats called a gel cell and don't have to be mounted upright, you can mount them upsidedown for all they care. Remember though, you can't have both batteries running at once. You need to isolate them, otherwise the moment you switch the car off the batteries will instant start trying to charge each other meaning you will have a constant high current flow between the batteries. Especially when their power levels are near equal. Being able to isolate the two batteries has another great thing...you NEVER suffer from flat batteries again;) If you mount the second battery in the boot...don't forget to vent it to the outside world...gas + enclosed area = ;)

I like the top of the line as well, thats why I use Nakamichi ;)
 

Phreddy

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Mmmmmmmm - Nakamichi.......

(spoont!)
 

Cameron

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Thanks for the advice ive done a bit of searching around for Nakamichi i can find all the other products but not batteries where have you purchased them before, are they the gel cell or starter type battery?
 

garfa

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couldnt you put the cap before the distro block? wouldnt that be the best place!?so you dont need tobuy 2 caps of course!
 

Cameron

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yeah, i think i got it, id need a 2 farrad cap installed jus before the junction to the two amps! i think, would two 1000wrms mono block soundstream amps rate or should i use another brand?
 

Tasmaniak

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Your amps are fine and yes, use either two one farad caps or a single 2farad cap if you can get hold of one. They aren't cheap.

and also yes, before the distro block, sorry if I confused anyone.
 

Tasmaniak

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once again, didn`t mean to confuse, but Naka dont make batteries..just one of the BEST speakers and amplifiers
 
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