I'm sure eurog35 will post this sooner or later, so I'll beat him to the punch. :P

When do you need a power cap? I currently don't have one and I don't experience any light dimming, but perhaps there are other indicators besides the dimming that I should be aware of when considering a power cap. My installers have said that caps are simply a bypass measure and the real solution is to get a more powerful alternator, but last thing I want to do is get a huge honking alternator that will suck up more HPs from my engine. I have a 500 watt monoblock amp and a 300 watt 2 channel amp that is currently being powered by the stock battery. Any other advantages to power caps? Cleaner power? Safer for amps?

TIA



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Nice poke at eurog35. Actually, I seem to remember him asking something about caps.

Caps provide a quick burst of power for the amps. If an amp tries to suck a ton of power for, say, a long, loud, low note it may not get enough juice. A cap holds juice in reserve to quickly satisfy the demands of the amp (in theory.)
It also acts as a filter for the power going to the amp.
If they didn't cost so much everyone would use 'em. Seems like a 1 Farad cap (they reccomend 1 Farad per thousand watts of amp power, you're at 800 watts, so . . .) would be indicated by those who want to sell you one! And they seem to cost over $100 for 1 Farad, from what I remember.

I've bought 'em in the past, but I'm not completely sold on the idea.

If you have the $$, it can't hurt.

 

You guys have the right idea about caps. They perform all of the functions you guys mentioned and many more. They do everything from the basic power reserve of delivering high amounts of current in short spurts, all the way to affecting the inductance of your system's power wire allowing current flow to be less restricted. They can also be used to filter alternator ripple.

They can very rarely hurt. While people seem to always mention them when it comes to dimming lights, that is not the best indicator of cap necessity. Just because your lights are dimming to the bass, does not mean that your amps are not getting sufficient current. In fact, it may mean just the opposite. It is indicating that there is current being directed away from your lights to your amplifier.

Now there is only so much current in your car available and eventually you will not have enough for your amps, headlights or any accessory. At that point you need an alternator.

In summary, a cap is an inexpensive way to have a little extra shot of current for when your amp calls for power during a dynamic note in the music. If the note is constant, the cap will not have time to recharge and will be rendered ineffective.

Please post any questions through this forum. Thanks.

 

heh shibal-z... i have a similar setup as you, but my lights dim when the bass hits, i have my bass level on my headunit at +9 or +10 out of 15... its an alpine... today my jl 300/4 cut off, and now it wont turn back on, i think my battery is weak, cause i drained it a few days ago playing with my system while the car was off for a long time, sigh... but if my jl 300/4 turns off, wouldnt my sub still play when my headunit is playing music? its weird cause my jl 500/1 still goes on fine, but i get nothing going into my sub, only my jl 300/4 wont turn on, i think it has something to do with my battery... sigh... i really hope i didnt damage my amp , its brand new too... i wouldnt think this would be the case tho, im sure JL puts all there amps through some very strenous tests, im sure an amp like this cant be damaged so easily like that... nothing was wrong in my system setup at all, everything has been working ever since, just that my battery is probably weak now, since it was totally drained, i couldnt even start up my car, i had to get it jump started...

so if (i pray pleaseee) my jl 300/4 turns back on, i will be sure to get a cap definetly, i will get a 1farad cap, and a bigger fuse, cause the jl 300/4 uses 40amp, and the 500/1 uses 50amp... thats a total of 90amp... my fuse is 80amp

where are the fuse on the jl amps incase you need to change em? theres no way i can damage my amp by playing my music at loud volumes, right?

 

I have a Monster Digicap 1 Farad I am looking to sell. I was thinking about throwing it up on ebay. I used it for 1 week before I got a great deal on a Pheonix Gold cap that I installed in its place. New they list for $199. If you or anyone is interested I'd sell it including air shipping for 100 bucks. I have the original packagin but as I mentioned it has been opened and used.

Just figured I'd mention it since the forum discusses the issue.

PM me

 

I may be interested. Just wondering why you replaced it with the Phoenix Gold? What's the difference between them and your reasoning for switching it out? Brand preference? Better performance? I'm assuming that they are both 1 farad units?

Thanks



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I replaced it because I got a great deal on the Phoenix Gold cap which I liked the "look" of better. I got the Phoenix Gold TPowerGrid10 to replace it (10 Farad). Yes I know it's overkill but I like how the cap looks like a small amplifier and has a built distribution connection. As far as which brand is better I wouldnt know which is better. As far as performance I would guess I am getting equal performance out of the Pheonix Gold as I was in the Monster Digicap since my system doesnt really require a 10Farad cap. I have pictures with the Phoenix Gold cap installed if you are curious.

http://www.vu.union.edu/~bichans/G35/IMGP1135.JPG

Let me know if you're interested.

 

You don't need a cap. Caps do nothing but improve bass transient response. Your installer is right, caps are what everyone thinks they need, when in actuality, you need another battery and/or higher output alternator if the current electrical system can't handle your car audio equipment's load. If your car right now isn't straining to meet your requirements, leave it alone unless you want a slightly better transient response. This is because caps can release their charge a lot faster and power your amp faster than the car's electrical system, so your bass response is faster too. You will need an absurdly large number of farads if you want the cap to be the sole bandage in a lacking electrical system. Soundwaves is right, caps will only work if you need a supplement for 1 bass note in the song. Most songs have xxbpm's.. probably higher than 10.. in which case caps won't work the way a lot of people believe them to work.

2003.5 G35C 6MT Blk/Blk

 

Doughster,

Enlightening. I can't imagine how any song would have a transient bass note when most music these days have XXXBPM. Prolly two digits for hip hop, but definitely three digits for trance and other electronica music.

Would getting a 10 farad unit be better like scobic has done?

Thanks


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I think my thing about the bpm's is a little ambiguous. I'm just saying that caps make your bass respond faster because it can charge/release faster than your amp. Like let's say if a bass note is supposed to occur at exactly 30 seconds into a song, the cap will allow it to come at 30 seconds, whereas a non-cap system, depending on the health of the electrical system and amp, will play that bass note a fraction slower. Can most people tell? Probably not... but audiophiles aren't most people. If bpm's are in the triple digits.. a single farad cap will not be able to keep supplying power. 10 farads will only prolong the time it takes for the caps to drain. It might improve your transient response if a particular song isn't too demanding with its bass notes. I thought your original post was asking about dimming? If you want to solve that the real way, you're going to have to get another battery/alternator. Like I said, you're going to need something like more than 1000 farads (not sure of actual number) if you want a cap to take place of the electrical system upgrade.

2003.5 G35C 6MT Blk/Blk