how many capacitors i need?

[henrytad]

hey.
im running 2 1800 watt amps, powering 2 rockford fosgate subs and 4 cadence speakers. i am starting to get the headlights dimming, battery current jumping, will i need just one capacitor to power the 2 amps, or do i need to get two?

[shiftySLE]

do a search on this or read some of the audio threads, I used to think a lot more highly of them than its worth, there are a few stereo guru's on here that will give you the details. Best part is, you will save the dollars.

[holdenboy]

No capacitors needed, buy yourself a proper deep cycle battery and upgrade your factory earths / alternator charge cable to 0AWG.

Optima make decent batteries, but they're expensive. Also look at the Absorbed Power range too.

[Tasmaniak]

Don't know if upgrading alt charge cable to 0ga is really going to make all that much of a difference though. UPgrading the factory battery to earth will definetly help the issue. BUt also make sure your current earths from the amp are solid as well. You know? Back to bare metal and all that. You said 1800 watts. Are we talking max on RMS? If it's max then just do those should be fine, if it's RMS now thats another animal altogether. Thats a lot of power dude and you need to do a lot of other things before you do a capacitor. For instance, How many earths do you have out of the two amps? On big systems, I don't have one earth. I tend to do multiple...like 2 or 3 going to different points. Like a spider leg out of the amp. Just give more points of contact. Is your power cable the correct size? Not to small is it?

Be wary about buying a deep cycle battery. It's not always the best alternative as they are not ideal as a start battery. If you want deep cycle though, definetly look at Optimas but don't worry about a yellow top. Stick to the red top, they are good as starting batteries as well as high current battery. Failing that, a battery high in CCA and RC will also work well.

If after all that you still have issues, then a single 1 farad capacitor should do the trick. or if it's truly 1800wrms then possibly head towards a 1.5 Farad cap.

[sweefu]

i'm not into caps myself but isnt a rule of thumb to go 1000wrms = 1 Farad? If your going caps may as well have them on the larger side than smaller i guess.
But like i said, not my thing.

[swiftymcfeat]

Just hook another battery up. Try get one of the dry-cell batteries as they provide a crap load more power.

[shiftySLE]

they could be talking complete crap, I cant be stuffed looking it up, but when a few of the stereo gurus on the forum explain properly how the caps work and why they are not necesary, it makes sense. If I do another sytem, I wouldn't be using them. Look up the old threads.

[| evaN |]

like the others have said, save your money and spend it on upgrading your wires.

Technical - Capacitors Tried & Tested - Mobile Electronics Australia

and how to stop headlights dimming
Technical - Stopping Headlights Dimming - Mobile Electronics Australia

[StoneX]

12 crapacitors are required.

[azkwazere]

lol @ stoneX

New Leads: $100
New Battery: $300
Time Spent Changing it all out: Hours and Hours...

Cost of a capacitor that will solve his issue in like 2 seconds flat... $100...

easy peasy.

aZk.

[holdenboy]

lol....i like it, crapacitors

[theSeekerr]

Your amp will have a substantial (probably not substantial enough, but I digress) capacitor bank already as part of its power supply. Adding additional capacitance to this is unlikely to solve your problem, and there are resonance issues that can arise from the resulting second order CRC circuit.

However, this is not a subjective case - you have a testable symptom. With that in mind, I suggest you try to borrow a capacitor, and then you can test for yourself if it resolves your issue. To gain a benefit from the capacitor, it should be as close as possible to the amplifier as possible - practically across the power terminals.

My bet is that you won't find it fixes your problem, particularly not the current surging (a cap charges much faster than an amp draws current). But since you CAN test it, please do.