i recently tried installing a capacitor for my subwoofers. i've been through 2 different ones and neither work. i followed the instructions to the tee and still nothing. i just tried to install a Monster digital capacitor and the damn thing wouldn't charge above 10v- and yes i let it charge for about 10 mins constantly checking the voltage with my voltmeter. then as soon as i disconnected it, it started to discharge on its own. i'm about to give up on the whole capacitor idea b/c it's costing me too much $$. i've blown out 2 fuses and i'm sick of the BS. anybody have ideas on why i'm having such trouble??

 

How much ACTUAL wattage are the subs/speakers seeing?

 

well it's a 400W amp that powers the subs only. the deck powers the speakers and they're rated @ 50W per channel, 200W for all 4 channels. the capacitor is 1 farad so from what i understand it's more than adequate, right?

 

If it's causing you that much trouble, I wouldnt even put it in the system.

The general rule of thumb that I have been told is 1F for every 1000W. And that's in actual wattage to the speakers, not the number on the amp. A LOT of amps have an RMS wattage that gets no where near the 'advertised' wattage.

That being said, you are not even close to 1000W and you shouldnt need the cap.

 

yea i think i'm just going to forget about it. i just wanted to prevent headlight dimmage- and i've already upgraded the battery, cables, alternator, and all the other necessary wiring. just thought it might help but its not worth the trouble at this point. thanks for the insight!

 

a capacitor is not a battery. The whole point to a capacitor is it is designed to dump it's entire charge it has stored in a fraction of a second (A battery it would take hours). It can only store the amount of voltage that it is given. If the leads going to it only has 10V then when you disconnect power to it, it can only have 10v.
----------
Since you're blowing fuses I have a bit of a safety tip I should add. DO NOT connect a capacitor backwards. It will explode. I've seen plenty of small ones pop. I can't imagine what would happen to one of those big ones.

 

yes i am WELL aware of that. i just installed a brand new AGM battery and it read 12.08v at the terminals. the cap was getting 12v but it was only taking a max 10v charge. a cap is supposed to store energy unless disharged. this thing couldn't even hold a charge. trust me, i know how capacitors work. and i know enough not to install it backwards- i've been working on cars for quite a while- even so, the cap i got has an alarm that goes off with a bypass if you hook it up backwards. and the only reason i was blowing fuses (the amp wire fuses) was b/c the cap wasn't fully charged and when i hooked it up there was too much draw and it popped the fuse. it's ok though cuz i've already said f--k you to the capacitor.

 

ok. just making sure. some of the questions on this board really make me wonder what's going on in the persons brain at the other end

 

Capacitors are useless. If you have dimming problems you either need a new alternator, new battery, or to upgrade the big three.

 

Caps have their purpose but most of the time, people do use them as a bandaid for a poor electrical system.

Not sure if you need a cap?
http://www.caraudiocentral.net/forum...ead.php?t=1888

 

A lot of times when I charge a cap it will only reach about 10 V or so with the resistor or light bulb inline for charging. EVERY cap I have installed has started to discharge when I remove the charge power. The fuses shouldn't blow even if you connected the power wire without the cap being charged. I would be looking for a possible short or something along those lines.
When you are charging it, are you disconnecting the wire form the cap itself, or are you removing the under hood fuse, connect the cap into the system and then use a resistor or test light in place of the fuse while charging? That is how I charge ALL of my caps and find it quicker and safer than trying to connect power at the cap, especially after it's charged. This will also charge all caps in the system, including the ones in the amp(s).

I'd also be interested in knowing how exactly you connected it into the system. I always bring the main feed from the battery to the cap, the ground from the chassis to the cap and then run the positive and negitive leads to the amp(s) and any possible processors in the system. this provides better filtering and better power supply stiffening than using a distro block and only connecting with two wires to teh cap back to the distroblock.

 

when i hooked up my cap (5 farad for about 150 watts--way too much) i hooked it straight from the battery thru the cap to the amp. then from ground, through cap to the amp... havent had a prob. and it helps the dimming... some what

 

yea thats the thing, it's a great bandaid till it starts to breat a sweat, then it doesn't work as well. So if you have a solid song of bass it will give in a little bit towards the middle of the song, as mentioned above, you need to upgrade your entire electrical system, a capacitor is made to help the amp procude those high power notes quickly, as the battery cannot supply all the power needed in a split second over 20 foot of wire, but a cap isn't so much to stop the dimming, it's a common misconception. Thats why in the above case, even though you have something so large as a 5 farad cap, you still have a bit of dimming, it's not a fix-all.