Car Stereo Question: 1 capacitor or 2?

[MasterAndCommander]

I'm thinking about adding a couple of amps to my car and would like to use a 1.0 farad stiffening capacitor right before the power distribution block splits into the 2 connection for the amps. All the setups I've seen use 1 capacitor per amp, I could do that as well with two 0.5 farad capacitors, but I'm looking to save a few bucks and some space by going with a single, larger cap...any thoughts from the car stereo experts out there?

thx!

 

[Heisenberg]

How big are the amps? 1 farad is a huge amount of capacitance. Unless you're running an insane amount of power, it'll do just fine for both amps.

 

[MasterAndCommander]

Originally posted by: Heisenberg
How big are the amps? 1 farad is a huge amount of capacitance. Unless you're running an insane amount of power, it'll do just fine for both amps.

One amp is 575W RMS and the other one I think is around 400W RMS. From what I've seen in the cap sizing guides, 0.5 farad for < 500W, 1.0 farad for 500 to 1000W. Does that sound about right?

 

[Heisenberg]

Originally posted by: MasterAndCommander

Originally posted by: Heisenberg
How big are the amps? 1 farad is a huge amount of capacitance. Unless you're running an insane amount of power, it'll do just fine for both amps.

One amp is 575W RMS and the other one I think is around 400W RMS. From what I've seen in the cap sizing guides, 0.5 farad for < 500W, 1.0 farad for 500 to 1000W. Does that sound about right?

I think that's about right. I'm trying to think if there's any advantage electrically to using separate caps instead of one for both. I don't think there is - it should work equally well either way. The only thing I can think of is wiring them separately might be better for noise, but I doubt you'll have a problem with that. I'd just use the one cap for both and it should be fine.

 

If your alt and your battery are good then why do you need one? I have two running fine, i could see if you had dimming and whatnot but if it aint broke.........

 

[MasterAndCommander]

My system isn't hooked up yet, I'm still gathering all the parts I need. I was reading several car install guides and the stiffening capacitor sounded like a good idea since my car has power accessories (moonroof, windows, doors, mirrors, etc.) Plus there is the coolness factor of having cap with a digital readout

 

[Viperoni]

A cap won't hurt, but make sure you have good power wire (I'd run a 4g with an ANL fuse underhood), and definetely upgrade your underhood wiring.

 

[MikeMike]

i say NONE.

they can help dimming, but are more like a bandaid than ne thing. the alt still has to charge the cap.

buy a new alt, or a new battery. ive run 1100 watts of power without anything but stock everything.

dont waste your money.

MIKE

 

[alkemyst]

I have a 1F on my sub amp only, solved my slight dimming at idle.

The amps are 425W for the sub peak and 2x55WRMS separates.


Most said only subs really gain from capacitors. Your musical amps won't and if you have problems with them you'll need to upgrade battery and alternator.

&Aring;

 

[Shockwave]

Caps = worthless.

Dont waste your money. My opinion.

 

[Cooljt1]

i would only get a cap if i got dimming. and if you get dimming i replace upgrade your alternator or battery.

 

[MichaelD]

Originally posted by: Shockwave
Caps = worthless.

Dont waste your money. My opinion.

I respectfully disagree. They work very well with any system with a big bass amp. I've used one in the past four rigs in my vehicles and regularly recommend them to friends.

The rule of thumb is 1 Farad of capacitance per 1Kw of amplification.

However, you can never have "too much" capacitance. It gets pricy though. Also, remember to use the same gauge ground wire as the power wire going to each cap. Very important.

One, 1 Farad cap will be cheaper than 2, 1/2 farad caps. Less cabling as well. I'd get the single 1 farad cap and either cable it into the main distribution block (what I do) or put it inline BEFORE the distro block.

 

[MasterAndCommander]

Originally posted by: MichaelD

Originally posted by: Shockwave
Caps = worthless.

Dont waste your money. My opinion.

I respectfully disagree. They work very well with any system with a big bass amp. I've used one in the past four rigs in my vehicles and regularly recommend them to friends.

The rule of thumb is 1 Farad of capacitance per 1Kw of amplification.

However, you can never have "too much" capacitance. It gets pricy though. Also, remember to use the same gauge ground wire as the power wire going to each cap. Very important.

One, 1 Farad cap will be cheaper than 2, 1/2 farad caps. Less cabling as well. I'd get the single 1 farad cap and either cable it into the main distribution block (what I do) or put it inline BEFORE the distro block.

Ok, thanks for the replies - That's what I will do - cable one 1.0f cap before the main distribution block w/4 gauge wire and ground it with same gauge. Any suggestions on capacitor brands? To save money, I was looking at this $73 one with the digital meter at Wallymart.

 

[Drakkon]

To save money, I was looking at this $73 one with the digital meter at Wallymart.

ACK!!!!11!!! if you MUST get a cap definately dont go with a wlmart one

I run about 1000RMS through my system and experience no dimming whatsover with dual 12's and NO capacitor...just a good yellow top battery and beleive it or not wallyworld 4 gauge wireing to the amps aand then more 10gauge schoshe wiring to the speakers

 

[EyeMWing]

Uh. A 1.0 farad capacitor costs between 2 and 5 bucks at Mouser. Unles there are special car audio capacitors

What the hell do you need a meter for? $73? WTF

 

[alkemyst]

Originally posted by: EyeMWing
Uh. A 1.0 farad capacitor costs between 2 and 5 bucks at Mouser. Unles there are special car audio capacitors

What the hell do you need a meter for? $73? WTF

For what input and output voltages/amperage?

 

[MasterAndCommander]

Originally posted by: Drakkon

To save money, I was looking at this $73 one with the digital meter at Wallymart.

ACK!!!!11!!! if you MUST get a cap definately dont go with a wlmart one

I run about 1000RMS through my system and experience no dimming whatsover with dual 12's and NO capacitor...just a good yellow top battery and beleive it or not wallyworld 4 gauge wireing to the amps aand then more 10gauge schoshe wiring to the speakers

Ok, I'm not getting the Wallymart cap...but I too used their Scosche 4-gauge dual amp wiring kit...can't beat it for $25 where CCity want's $90+ for something like it w/o the RCA cables

I'll probably get something from Lightning Audio, or such.

 

[Shockwave]

Caps are worthless

Thats a test showing system voltages at the amp, with and then without a cap inline. You can see VERY little difference. Aside from that, amps have caps built in to them so to be honest if you have an amp you already have caps.
My opinion anyways.

 

[MikeMike]

truthfully, spend your money on a battery. caps will bandage your system. they will stop dimming, but your alt will continue to run 24/7/365 until you can hold a larger amperage for longer.

yellow tops are decent, but pricey, find an interstate battery, nice one, ask around, i dont know batterys.

MIKE

 

[alkemyst]

It's like extra cooling fans on a PC...sometimes you need them sometimes you don't if you don't need them they aren't a smart choice.

If you are on the borderline during bass peaks only then a cap will help. A new battery and more importantly probably the alternator may solve the problem...it could still be inferior grounds and power cable. The battery is just storage, your car will more or less 'run' off the alternator once it's running (basically)....more othen than not just a new alternator of higher output is needed.

&Aring;

 

[SilentZero]

Caps are ok to have if you pushing alot of power. I have used them before, athough got away from them and just started using the optima batteries instead. As said above...if not needed it might impair your system.

 

[MasterAndCommander]

Well, it looks like those who said I needed 0 caps are right so far, I just had my mono amp and subwoofer connected today at Circuit City (I want to add, they did a sloppy job, I'm gonna have to re-position the wires myself

-- It's a good thing I did all the hookups to the headunit and the mounting in the trunk all by myself).

I don't have a lot of music with heavy of base, so I had to settle with "The Bad Touch" by the Bloodhound Gang to test it out , and boy did I feel a thud, thud when the subwoofer kicked in ... anyways, the lights didn't dim, no problems driving on the interstate, my power accessories worked fine, so I guess my alternator is ok.

Next step is to get the 4 channel amp...thankfully, I used a distribution block in the trunk, so I won't have let those doofuses at CC mess with my car again...I only did it because free installation came with the amp - which I'll never do again even if it's free. Thanks for the info guys. I'll hold off putting the 1 farad cap until after I put the second amp in and see if dimming becomes a problem.

 

[MasterAndCommander]

I seem to have found a good site for the pro's and con's to the great capacitor debate:
http://pub14.ezboard.com/fcaraudiotalkfrm27.showMessage?topicID=10.topic

 

[Shockwave]

Originally posted by: MasterAndCommander
I seem to have found a good site for the pro's and con's to the great capacitor debate:
http://pub14.ezboard.com/fcaraudiotalkfrm27.showMessage?topicID=10.topic

Thats a pretty poorly written argument in my opinion. He talks about meeting transient demand. Well no shyte. Why do you think amps have caps BUILT IN to them. And making the sub faster? Sure.
I see alot of iffy to flat out wrong data, and no test and measurement data to support his claims.

Again, my opinion.