i'm running 2 12" subs, on a 1000W amp. how many farads do i need in a capacitor? I know a farad is a measure of energy, but whats the difference between buying a 1.5 farad cap and a 40 farad cap? Can anyone exlain the whole "farad" and "capacitor" thing to me?

thanks.

 

normally reccommended 1 farad per 1000 watts, i'm sure 1 farad would be plenty for your system, next time though, this question should be in the audio/security section... you'll get a reply faster. good luck

farad is the size of the capacitor, which is what the cap stands for in "farad Cap" basicly it stores power for when the bass hits so your lights don't dim ect... making the load lighter on your charging system and battery...

the difference between 1 farad and a 40 farad cap is 39 farads or 39,000 watts.... 40 farad = overkill.
1.5 farad = 1,500watts.

it's just reccomended that u use 1 farad for every 1,000watts. but if u have 1200-1400watts running off a 1 farad i don't see the prob....

i know that's not the exact definition, but it's a very good very understandable way to explain it....

 

right on. i had a basic understanding, just wanted to make sure i was 100% correct. thanks!

 

might want to keep in mind, a better battery, or better alternator might be more worth it, these caps should not be mistaken for extra storage batteries... its only a few seconds worth if that, and just as said, only to even out very very short and very loud powerful spikes. but its up to you, id recommend it only if you have a nice battery first though and unless your concerned with keeping the battery longer a little longer from the variations in power drain... only get the cap if your lights are dimming on music or whatnot.... an alt would be nice too, but unless you install it yourself, labor Cost on civic alts will kill you, let alone the price of a good higher power alt.

 

dont bother with today's car audio cap.

 

yea the cap **** is pretty useless like said above.

I would sugguest upgrade your ground wires the big 3.

then a bigger alternator say good 170amp and a deep cycle battery. remember it might not help fully but it will help much better then getting a CAP.

remember the alternator doesn't charge 170amp at Idle it will only do 170 at certain RPM like above 2000rpm. If you get a bigger alternator u will have to upgrade the main wires like alternator ground etc..

honda alternator are less then 90amps around 70-80amps. also remember the more **** you have airbag etc the less amps u have to use..

0 guage will be ur best friend.

 

i dont know how much exactly, but i got a 1 farad cap for my 10w7 and 500/1 amps both pushing out atleast 500 rms. Now it doesnt do as bad, but i can still get my lights to dim, so get a little more than you think you need.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jbkiksass69 &raquo;</TD></TR><TR><TD CLASS="quote">i dont know how much exactly, but i got a 1 farad cap for my 10w7 and 500/1 amps both pushing out atleast 500 rms. Now it doesnt do as bad, but i can still get my lights to dim, so get a little more than you think you need.</TD></TR></TABLE>

that's right, next prob is your alternator, keep in mind although everyonesays that ohh the acura alt puts out 80amps.... yea that amperage is maximum.... my little b16a alt puts out 48amps at idle

time to upgrade and that will be atleast 125$ + install... for a new high output alternator, like 90amps... don't want to go crazy just drop the headlight and dashlight dimming when heats on...

keep in mind your heater and rear defroster prolly take up the most power from your bat...

according to the people at conrel (alternator rebuilders) honda/ acura alt's are a bitch to reliably put out good constant power.

 

The alternator, engine grounds, and battery will be most important for you.

And if you're not running the system when the car is off, then the battery becomes much less important. In that case, you'd only want a larger battery if perhaps you have a POWERFUL system (talking about something that requires 200+ amps here).

And yes, make sure to take a look at the specs of an alternator. The spec at idle is very important if you listen at engine idle...

Dom. Iraggi makes custom alternators for cheap - I think he's your best bet for an aftermarket alt (price/performance).

I'm not convinced that a cap is useful; more often than not, I see a decrease in SPL when caps are used (acts as an additional load for the alternator which must continually be resupplied in spikes on demand due to its nature). --- Now in theory that may act as a buffer, analogous to using a large water reservoir for a liquid cooling system, but I just don't see the analogous benefit!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2fast4udude &raquo;</TD></TR><TR><TD CLASS="quote">whats the difference between buying a 1.5 farad cap and a 40 farad cap?</TD></TR></TABLE>

I had never heard of a 40 farad capacity on a capacitor. Sure you don't mean 4.0?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin_Bradley &raquo;</TD></TR><TR><TD CLASS="quote">

I had never heard of a 40 farad capacity on a capacitor. Sure you don't mean 4.0?</TD></TR></TABLE>
They do have these stupidly large values of capacitors the problem with them is the ESR is so large they act like a battery not like a cap.

Capacitors serve a purpose that a alternator nor a battery can make up for. They are faster then either. The purpose of the cap is to make up for the slowwww electronics of the alternator charging system. They weren't designed to keep your lights from dimming this is just an added benifit. The peak current demands can be very high this is why your lights dim. Your alternator nor battery can deliver the current fast enough so you end up with a voltage drop, which is why your lights dim.

Even with a larger alernator and larger battery your lights will still dim. why? same reason as above. You can go without but know that you are cutting off the peak levels of your output. Does this matter well thats up to you.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CivHatchH22 &raquo;</TD></TR><TR><TD CLASS="quote">


i have a 100 farad cap, bought it for $100.</TD></TR></TABLE>LMAO.... 100 farad cap, do you know how big a 100 farad cap would be, a 1 farad cap is about the size of a litre of milk so.......... 100 farads 100 litres of milk , you tow a trailer for them
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">
They do have these stupidly large values of capacitors the problem with them is the ESR is so large they act like a battery not like a cap.

Capacitors serve a purpose that a alternator nor a battery can make up for. They are faster then either. The purpose of the cap is to make up for the slowwww electronics of the alternator charging system. They weren't designed to keep your lights from dimming this is just an added benifit. The peak current demands can be very high this is why your lights dim. Your alternator nor battery can deliver the current fast enough so you end up with a voltage drop, which is why your lights dim.

Even with a larger alernator and larger battery your lights will still dim. why? same reason as above. You can go without but know that you are cutting off the peak levels of your output. Does this matter well thats up to you. </TD></TR></TABLE> Ditto all the above 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">LMAO.... 100 farad cap, do you know how big a 100 farad cap would be, a 1 farad cap is about the size of a litre of milk so.......... 100 farads 100 litres of milk , you tow a trailer for them </TD></TR></TABLE>

Size really has nothing to do with it. A 100 Farad capacitor can be made small if it was made out of a different dielectric material. The large caps you use in your car are made out of foil and wax paper rolled up. (thats the best I could come up with as a description). This is mainly because its cheap to produce. There are better dielectrics but they are way more expensive. Most of the large caps I have seen have ESR values so high they function more like a battery. This doesn't mean one can't be made. The problem with making are large value cap with a low ESR is the cost to produce it.

The other problem with some stated ESR values is you need to know what frequency those measurement were taken at. The ESR at one frequency will not be the same at another. IMO I wouldn't pay attention to values taken lower then 44kHz.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">LMAO.... 100 farad cap, do you know how big a 100 farad cap would be, a 1 farad cap is about the size of a litre of milk so.......... 100 farads 100 litres of milk , you tow a trailer for them
Ditto all the above 94</TD></TR></TABLE>


its about 3/4 the size of a normal battery.

 

a cap can actually hurt you. they cause resistance which takes away power. they are design for short bursts of power.the best thing to do would to be upograde your battery to a optima or stinger, upgrade your wire. and if that still doesnt help then an alternator.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo_1 &raquo;</TD></TR><TR><TD CLASS="quote">a cap can actually hurt you. they cause resistance which takes away power. they are design for short bursts of power.the best thing to do would to be upograde your battery to a optima or stinger, upgrade your wire. and if that still doesnt help then an alternator.</TD></TR></TABLE>
Wrong a cap does not represent a continuous load. A cap at DC is an open circuit no load at all. It does not function it the way you have described.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo_1 &raquo;</TD></TR><TR><TD CLASS="quote"> upograde your battery to a optima or stinger, upgrade your wire. and if that still doesnt help then an alternator.</TD></TR></TABLE>

Optima will not be as good as a SVR 50 if he gets the civic sized one in the stock location. Ive made a post on this... The SVR, when matched with the same size Optima (at least the civic sized, 51R), outperforms it in storage and recharge.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">

Size really has nothing to do with it. A 100 Farad capacitor can be made small if it was made out of a different dielectric material. The large caps you use in your car are made out of foil and wax paper rolled up. (thats the best I could come up with as a description). This is mainly because its cheap to produce. There are better dielectrics but they are way more expensive. Most of the large caps I have seen have ESR values so high they function more like a battery. This doesn't mean one can't be made. The problem with making are large value cap with a low ESR is the cost to produce it.

The other problem with some stated ESR values is you need to know what frequency those measurement were taken at. The ESR at one frequency will not be the same at another. IMO I wouldn't pay attention to values taken lower then 44kHz.</TD></TR></TABLE>I understand that, I did mean the ones you get from Stinger, Monster, PG, Scosche and the like, do you know of a 100 farad cap that you can get for $100 that will fit into a car?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CivHatchH22 &raquo;</TD></TR><TR><TD CLASS="quote"> its about 3/4 the size of a normal battery.</TD></TR></TABLE> Show me.... I have been installing for a long time, and I have seen some 10 farad caps, [ 10 1farads wired inside a case the size of a large batt.] but I would like to see a 100 farad cap 3/4 the size of a normal batt. 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Majin Vegita &raquo;</TD></TR><TR><TD CLASS="quote">
keep in mind your heater and rear defroster prolly take up the most power from your bat...</TD></TR></TABLE>

Your heater???!?? How so??

Alumapro makes a 50F cap that is about the size of a small amplifier.

 

I must agree, if Heat took only power, then I wouldnt have to wait until the engine warmed to get hot air...

If I were to guess, Id say power windows, when they are already up, pressing the buttons to make sure they are up takes the most power, its the only time my lights dim...

Beyond that.... bright headlights my guess...

 

I have a 1farad RF Capacitor hooked up to my system, running 800-1000watts raw powa! Pumping my 12w6v2, seems like a overloard yeah but it very nice. At first i was on a 600.2 RF amp @ 200RMS Watts bridge, no cap. it dimmed. Got the bigger amp, and the cap, and it doesnt dim nearly as much anymore.

 

nope. i definatly mean 40. i couldnt believe it either until i saw an ad in SPort Compact a few months back.. i think it may have been lightening audio, i cant remember now. whoever it is, they make a 40 farad, a 100 farad, and a 200 farad cap... amazing stuff

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2fast4udude &raquo;</TD></TR><TR><TD CLASS="quote"> but whats the difference between buying a 1.5 farad cap and a 40 farad cap? </TD></TR></TABLE>

LOL my favorite subject
Whats the ESR and ESL of both of those products your looking at? Also what frequency were the measurements taken at?

 

i'm not even remotly interested in such a large cap anyway. i just needed to know wtf a farad was so i could make the right choice. bought a 1.5 farad cap last week :D Pheonix Gold

 

That should be more than sufficient for 1000W.