Cap

[netherland24 5,000+ posts]

alright i hear back and forth that caps are bad do BIG 3. well i have been reading alot and stuff and caps are usefull they charge the system so it dosent drain and it dosent cause dimming of light.

can anyone really tell me the BIG difference

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[Raisedin305 5,000+ posts]

From what i know (heard) a cap stores up power from the battery to help you hit really low notes so NO it doesn't help "recharge" your system. Some people say it helps alot and makes a world of a difference...others say they are a piece of shit

 

[RandyJ 10+ year member]

From what i know (heard) a cap stores up power from the battery to help you hit really low notes so NO it doesn't help "recharge" your system. Some people say it helps alot and makes a world of a difference...others say they are a piece of shit

It has nothing to do with frequency....

The cap will hold a charge and let it out when needed, such as fast kick drums or a sudden, high power demanding note. The cap though must charge to get that power thatit holds, which is why most of them do not do shit for the average persons system. This is so because if the electrical system cannot support the current accessories that the person is using, then the added strain of a capacitor which is constantly requiring charging will only make things worse.

Get it now?

 

[Savstyle 10+ year member]

heard 3 systems with caps and then removed. heard no difference at all. and all 3 had big 3 done and had no dimming. IMO Caps=Teh Useless

 

[Raisedin305 5,000+ posts]

heard 3 systems with caps and then removed. heard no difference at all. and all 3 had big 3 done and had no dimming. IMO Caps=Teh Useless

//content.invisioncic.com/y282845/emoticons/iagree.gif.15d6c075ee8d3913ba26866d06993068.gif To me caps are just there for the cool looks of it (for the ones that actually look cool). I was at a recent car show and you hear people talking all this crap about other peoples car that were in a SPL competition saying "man that guy sucks he doesn't even have a cap or nothing" I was like wtf:slap:

 

[PowerNaudio 10+ year member]

here,

Stiffening capacitor

From Wikipedia, the free encyclopedia.

A stiffening capacitor (aka power cap) is a Car audio component designed to provide power during times of peak load. The large capacitor acts as a dampener for the audio power system.

In high power audio applications the amplifier can require more current than can be supplied by the car battery, because of the battery's discharge characteristics. The slow power delivery can result in poor sound quality, dimming of the car's lights, or other electrical maladies. For audio applications that only require short bursts of power, such as a thumping bass line, it is more economical to install a power cap than to upgrade the car's electrical system.

The power cap, usually 1 or 2 farads, is connected in parallel between the battery and the amplifier. Multiple capacitors can be connected with busbars to reduce resistance and power loss. The capacitors are quite large and are often decorated with graphics or enclosed in an attractive housing, sometimes with readouts to monitor the capacitors voltage.

The capacitor charges and discharges rapidly, much faster than a battery could. It can only hold a small charge, so a single bass hit can empty it completely. It charges back up when there isn't a large power demand. This makes it inappropriate for systems that will require prolonged delivery of power, as the capacitor cannot supply additional power, only store it temporarily.

A power cap will not help if an audio system requires more power than the vehicles electrical system can deliver. While this usually requires upgrading the car's battery or alternator, a low-cost improvement is to upgrade the "magic three wires." Using thicker wires can increase the current capacity of the system. The three wires are:

the wire from the battery's negative terminal to the car's chassis (ground).

the wire from the alternator to the battery's positive terminal.

the wire from the chassis (ground) to the engine.

These 3 wires are often small and need upgrading. Fixing this common bottleneck is cheap, and is more effective at powering your stereo and preventing the head lights from dimming.

 

[adam71 5,000+ posts]

Here is a shorter answer. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

From bcae1.com

If the capacitor does its job, the added voltage (less voltage drop means higher voltage available to the amplifier) would give you more power output, especially with amps with unregulated power supplies.

http://www.bcae1.com/capacitr.htm

You probably noticed that I said 'supposed_to_do' earlier. This is because there has been some discussion as to whether a capacitor is a help or a hinderence when it comes to keeping the voltage at a higher level than without it. Of course, if you ask someone that's spent more than $100 on a capacitor if it helped, they'll tell you that it has. Why on earth would someone 'fess up' to wasting that much money on 'snake oil'. I've yet to see a capacitor increase the SPL in any system.

The only beef I have with this statement is that I never thought of a capacitor being able to increase the SPL of any system. I always thought that a cap was just there to limit voltage drops......NOT add more SPL. Which is why I question what he's saying.//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[Fitz 10+ year member]

from my exp at local comps, cap actually HURTS spl... (puts one more resistor in power line)

 

[iceteebone 5,000+ posts]

It has nothing to do with frequency....
The cap will hold a charge and let it out when needed, such as fast kick drums or a sudden, high power demanding note. The cap though must charge to get that power thatit holds, which is why most of them do not do shit for the average persons system. This is so because if the electrical system cannot support the current accessories that the person is using, then the added strain of a capacitor which is constantly requiring charging will only make things worse.

Get it now?

//content.invisioncic.com/y282845/emoticons/iagree.gif.15d6c075ee8d3913ba26866d06993068.gif

 

[RandyJ 10+ year member]

//content.invisioncic.com/y282845/emoticons/iagree.gif.15d6c075ee8d3913ba26866d06993068.gif

Ye know, I think everyone else ignores me on the topic of caps except for you. While the explanations from bcae1.com and wikipedia may do the job, mine is put real simple and in lamens terms. Whats so hard about it?

 

[RandyJ 10+ year member]

The only beef I have with this statement is that I never thought of a capacitor being able to increase the SPL of any system. I always thought that a cap was just there to limit voltage drops......NOT add more SPL. Which is why I question what he's saying.//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Well, if the capacitor regulates the voltage drop then presumably there will be more voltage going to the amp when it is being demanded. When someone is burping, the voltage will most likely drop a fair bit. If a cap is there to fight against a change in voltage, then more wattage will be fed to the sub. We know this because P=IV, Pbeing power, I being current and V being voltage. With more voltage and the same or more current, power will go up, and more power in an SPL install could be the determining factor between 169.9dB and 170dB //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Spr0ket 10+ year member]

I'm going to take this snippet from another site (http://www.306motorclub.com). Big Tom sums up my thoughts on the usefulness of capacitors. Have at capacitors as you will, it's your money. Eventually I'll put all of my thoughts and conversations on the usefulness of capacitors into one web site and submit it to the12volt when it's back.

After reading [a few] comments I decided to go upstairs and talk with my boss Ed Mietner. Some of you may know of him but most I doubt will, but he is pretty much a God when it comes to anything home/car audio. He used to design amplifiers and digital crossovers etc etc for Orion and A/D/S before starting up the company I work for.
Anyways, back on track. Ed got talking about the benifits for caps in car audio but he like you ... got talking about the ESR and ESL and how it is far more benificial to run multiple smaller caps opposed to one larger cap do to the ESR. But then he also got going on how if you really want to do a good job filtering out the ripple you would need to calculate the inductance of the power cables and get the scope out and calculate for the switching frequency of the amps power supply and then you can determine the value of capacitance needed and which type of cap to use to best eliminate the ripple and yadda yadda yadda...

It's tough talking with Ed, he goes way above and beyond the answer you are looking for. So I told him about the tests ... with the guy using an Audio Precision unit (Very nice equipment, I have one in my office for testing our preamps) and the 15F cap, and basically he said it's retarded using that high of a cap, he was suprised anyone would even buy one like that, so I told him about how nowadays you can pick them up alot bigger then even that and he just shook his head.

So what I gathered from him was that caps are a very important if you use the proper caps (Like as said, low ESR & ESL values) Simply because not to gain any dB's or stop dimming lights but to reduce the ripple and prolong the life of the amp. Because apparently with the high current and changing voltages the input caps of the amplifier heat up do to the ESR and cause them to fail down the road. An example Ed said was a prototype Orion 8 channel amp he helped design that pulled about 375A at full power, after awhile of testing the bank of input caps physically melted. They replaced the caps, and put a series of smaller caps inline with the power supply to smooth out the ripple and never had a problem afterwards.

---

After talking with Ed I figured I would talk with another guy who works here who also has been in the industry for a long time and he sent me a message saying

"they're useless if your electrical system/wiring is in good order and adequate for your amps. they just look cool like the "flux capacitor" in Back to the Future DeLorean. It's a lot of dough for a small improvement in sound."

I think it's funny, even when you ask the guys who are considered by alot of people to be some of the best in the industry, they have somewhat opposing views on the subject of caps.

So I soppose it comes down to if your electrical system is adequate you don't really need them, but it's definatly not a bad thing to have them in if you keep the size down and use decent caps. agreed?

 

[yischrax 10+ year member]

When you say adequate you need to think about a few other things too. It isn't always possible or that reasonable to have dual alternators like some people need (I being one of these people). For instance I am running an us amps us 1000x on my components soon I am looking at going with a 3 way fully active component set looking at seas excel mid bass mid and highs so they are 6 and 8 ohm I will be then running a 1000x and a set of 600x's to my front stage and a 2000x to my RE XXX I have a 250 amp alt and a 2150 cca battery. this is Adequate because for normal operation I will have enough power from the alt. my battery WILL and CAN be used for the rest of the gap though it being large it has a low response time or ESR using caps it can fill in this response from when the alt can no longer supply a charge and the battery is called upon. For a true adequate electrical system I would need to have dual alts and just use the battery to take out the AC ripple the rectifier cannot. Also for people running yellow tops and other thick plated batteries for more durability for there starter battery up front along with the long run from front to back will have a slow transition response. Capacitors (of proper capacitance) can help lower this transition response. No, you cannot have a system that calls on 300 amp draw and run a 150 amp alt and a 600 cca battery and say it is adequate but a 200-250 amp alt and a battery that is 900 cca is sufficient I think.

Earlier it was said that fz of the tone generated will not make a difference but to make a tone at 100 dbs at 90hz will it not require less power than what it will require for a 40hz tone because it will need to move farther to produce the lower tone. For this reason it dose make a difference on the tone.

I like having a good amount of bass when I am in the mood but am more of a sound quality guy myself and I don't think you would usually hear the difference of a small voltage drop but depending on instal equipment and such (class of amp class D compared to class A/B what is going to take a larger draw to make same amount of power and what is cleaner)

So my final thought is if you are looking for a cap to make a difference in spl I don't see it happening if you are looking to make a flatter sound in music for better sound quality if everything else is right I think it will help.

In spl comps isn't it mostly the batteries your using for a power supply? So it would make sense in that case that the added resistance though it is not much will hinder your score because once the battery starts discharging voltage should stay roughly the same voltage and you usually have a short run of wire from battery to amp in that case.

 

[adam71 5,000+ posts]

Well, if the capacitor regulates the voltage drop then presumably there will be more voltage going to the amp when it is being demanded. When someone is burping, the voltage will most likely drop a fair bit. If a cap is there to fight against a change in voltage, then more wattage will be fed to the sub. We know this because P=IV, Pbeing power, I being current and V being voltage. With more voltage and the same or more current, power will go up, and more power in an SPL install could be the determining factor between 169.9dB and 170dB //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Ok, I see what it meant now....thanx. The reason the paragraph threw me off was because it seemed like he was saying that it was supposed to add more dbs. When I think of supplying more voltage to the amp when needed I think of it being a reserve to be used only when line voltage has dropped below normal, NOT to be used to get louder.

 

[3.5Max6spd 10+ year member]

buy caps for the right reasons...

1) dont have nothing better to spend your $$ on..

2)for show-finishing touches...

3) for the voltage meter/distribution

Anyone who truly experiences a cap better their system response/dynamics, should look into investing into better amplifiers with a proper power supply design...

That being said my hypocritical arse will be adding a few when I redo my trunk for the above reasons listed