Is a Capacitor worth it?

[midnightg35x 10+ year member]

I'm glad ecrack did all the gruntwork explaining this rather than me. I've tried before and it just gets tiring //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[quins90lac 10+ year member]

your talking normal every day electronics and in that case yes caps are needed i will give you that . but in a CA situation no their not needed if you have a good electrical system and good battery. why do you head back over to SMD or what ever sight you came from and ask Steve Meed if he puts caps in his customers vehicles. Now back the first question asked in this thread . do you need a cap no you need to upgrade you electrical system like some one else said 0/1 wire and a new deep cycle AGM battery

 

[slim2fattycake 10+ year member]

I understand as well and caps DO have their place. There are just a bunch of idiots on here that think they know that have no idea. Also to the idiot that said if caps are so great why don't the loudest systems in the world need them?... the answer is extremely simple. They use huge banks of batts. They don't use an alt to charge them so the voltage doesn't fluxuate. The voltage is the batts resting voltage. They burp their system, hit their score and then go home and put the bank on a charger. A daily setup uses an alternator to charge. The alternator's voltage is about 2v higher than the batts float charge. This is like this so the batt can charge while the vehicle is on so it can crank the engine next time. The reason for the alternator having a higher voltage than the batt is because CURRENT FLOWS ONLY FROM THE HIGHEST SOURCE OF POTENTIAL. (potential = voltage) This means that while the vehicle is on the circuit voltage is 14.4v. When the bass hits, there is a tremendous amount of current drawn. The voltage regulator in the alt sees this and turns the voltage down to reduce the current being drawn from the alt to protect it. (voltage and current stay proportional, when the voltage drops, so does the current draw) Once the circuit voltage reaches 12.6 or whatever the batts resting voltage is, it will begin to discharge. .... now that we understand that....the alternator puts out alternating current or AC just like your house has. It has a built in rectifier to convert AC to DC but it does not do it very cleanly. This means you get AC ripple. Capacitors are used in EVERY piece of electronics that you own to filter this AC ripple and it is no different in car audio. A heavy bass draw is AC ripple. When properly implemented, capacitors can greatly reduce this AC ripple and sustain the voltage near 14.4. Batteries cannot do that as they do not discharge until the voltage is near 12.6.

Now, go learn some BASIC electronics and come back and apologize. Stop listening to the caraudio.com douchebags that think they know and don't have a clue.

I don't claim to know everything or claim to know much but if amps already have power input filter caps in them to deal with the AC ripple then why would there be a need to use an external cap?

ps- I like the name of your forum. lol. Its exactly what it is.

 

[smoka 10+ year member]

Batteries cannot do that as they do not discharge until the voltage is near 12.6.
Now, go learn some BASIC electronics and come back and apologize. Stop listening to the caraudio.com douchebags that think they know and don't have a clue.

Please stop posting this false info. Its funny how the noobs believe you.

12.6v is a batts floating voltage. Its called a "floating voltage" because it CAN and DOES discharge at voltages above that.

You are the one that needs to go take classes, because you don't understand ohms law and how voltage and current relate to each other.

 

[haloweenhamster 10+ year member]

sorry started writin that 2 hours before i finished

looks like alts r inteligent now

sorry for disagreein with u

 

[smoka 10+ year member]

the alternator puts out alternating current or AC just like your house has. It has a built in rectifier to convert AC to DC but it does not do it very cleanly. This means you get AC ripple. Capacitors are used in EVERY piece of electronics that you own to filter this AC ripple and it is no different in car audio. A heavy bass draw is AC ripple. When properly implemented, capacitors can greatly reduce this AC ripple and sustain the voltage near 14.4.

Ok, thats ONE use for a cap. But it doesn't apply to anything the OP asked about.

I don't feel like typing it all out, so I just copied an old post that gives a decent explaination relating to voltage drop with caps. I'm not going to link the old thead because your dumbass will post on it. So credit goes to 518wrx for originally posting this:

There are a few benefits to using a cap in a daily driver. The cap installed near the amp is able to discharge faster then the battery upfront. This allows for less strain on the alt. due to the fact that there is less resistance compared to pulling the same amount of current all the way from the battery (resulting in a lower voltage at the amplifier). The cap will recharge quicker then any of us can measure so don't worry about it only helping the first hit. One major problem is most people that need a cap are usually maxing out their amplifiers consistently, as opposed to someone that uses them to "critically listen" to music. When the gains are set properly the amp is very dynamic, some beats on the drum are not as loud as others, and you can tell the difference. In that scenario the cap helps on the big swings. When pounding down the street with a bass CD in, the amp is not "swinging" at all, it is constantly using everything it has, and this is using more current then the alt. and battery want to give up. This is why your lights dim on every bass note. The chance of a 1 farad cap helping this are very slim to none. The reason is the alt. can't keep up and charge the battery and the cap. A bigger alt. would be the way to go. Or for a quick fix add a second battery in the trunk. This will help with the lights dimming and put more power in the back (because it stores more energy then a cap). You still have the problem that the alt. cannot put out enough juice to properly charge both batteries (that means charge them and maintain them at 14.4v) The trade off here is the same reason that the caps don't work for SPL-----
The extra battery and the cap both become a load to the alternator.(just like your amp is a load on the battery and the alt.) So the alternator basically "bogs" down and the operating voltage will be lower with more "loaded" on it. Your spl numbers will go down as the voltage goes down (NOT AS NOTICEABLE WITH A TIGHTLY REGULATED POWER SUPPLY). This is why most guys in street class gain almost a dB when they take out their caps. They have raised the operating voltage of their amps.(remember this is only for a short burp).Much in the way that ss and extreme guys "up" their voltage to get more power out of their amps.(remember that an amplifier steps voltage up inside so 1 volt difference can be a lot of power------ 12v in x3=36v+ and 36v- =72v across speaker leads now square that and divide by 4 ohm load= 1296 watts...... now with a 13v supply 13 x3=39+,39-=78v x 78v=6084/4=1521

1521-1296= 225 watts difference by maintaining 1 volt higher)(keep in mind your 4 ohm speaker has an impedance curve that is much higher then 4 ohms at most frequencies so real power is much lower)

The way caps have helped in most cars is that the alternator now has another load. This load now lowers the average operating voltage of the cars electrical system example:

Before system- car running nothing else on 14.4v

Add system- system down 14.2v- when bass CD is pumping- 12.4

Now your electrical system is varying between 12.4 and 14.4v---- a 2 volt swing

Now add in a cap or two and the system now charges at 13.4v

Now your system will still dip close to the same 12.4v, but the high is now only 13.4= a 1 volt swing

Now your headlights dim half as much because there is only half the swing in voltage.

Now if you put a second battery in the back (more storage) the operating voltage will drop even more, lets say 13 volts (now you are barely charging the batteries without upgrading your alternator) By adding the battery in the back, you no longer are loosing voltage along the wire from the front battery. Also you have a lot of storage (2 batteries) so when you bass it up the power is coming mostly from the batteries and the alternators job is just to charge those batteries. So now when the amp hits a big rolling bass note the batteries will only drop to 12.6v

Now your swing is from 12.6-13v and .4 voltage drop on a headlight or dash light is next to nothing especially when compared to a 2v swing.

One other suggestion is to ALWAYS upgrade your ground wire at the battery. This is the least expensive way to make a huge difference in light dimming. There are a lot of cars that use a 8 or 6 gauge ground to the body (remember when you grounded your amp?) This cannot support the current return of the headlights and a 1000watt amp. Remember you may have a dedicated 4 gauge lead to the amp, but when that current returns to the battery it shares that ground with all the other components in the car that are grounded to the body.

All of the numbers in this post were submitted to show a point and do not actually reflect a single test environment. They only are used to help visualize what is happening to your cars electrical system when you go crank your bass up all the way and cruise down the street. Hope this has helped.........

Gary Bell

Now eCrack stfu.

 

[midnightg35x 10+ year member]

I don't claim to know everything or claim to know much but if amps already have power input filter caps in them to deal with the AC ripple then why would there be a need to use an external cap?

Like any piece of electronics, sometimes an amp is designed with insufficient or otherwise inadequate parts. If you look at any of the "beefier" amplifiers, one of the main things to look at is how many large rail capacitors it has. As stated before, adding an external cap will not get you any extra dB's in an SPL competition or anything magical like that, but it certainly can help cure any voltage ripple. It works along the same principal as the line conditioners you can get for your home theater/computer equipment.

Also seems similar to asking why would you need extra batteries for a 10kW system when you already have one. Sometimes it just isn't enough //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[haloweenhamster 10+ year member]

a good rigid supply makes for good sound

look into hifi sound systems like krell

so 14.4v - 12v or less makes a big difference

a cap acts like a buffer to stablise the supply

unless u have a constant tone or maybe play DUB or BASSLINE

it may not recharge in time to make a difference

 

[smoka 10+ year member]

electronics engineerwork with electronics everyday

what do u lot do work at macdonalds and play with cars in ur spare time?

go and search discharge rates for urself and see the differance

A real EE would call himself an Electrical Engineer. Stop pretending.

 

[Stalin-ohaulic]

Ok, thats ONE use for a cap. But it doesn't apply to anything the OP asked about.
I don't feel like typing it all out, so I just copied an old post that gives a decent explaination relating to voltage drop with caps. I'm not going to link the old thead because your dumbass will post on it. So credit goes to 518wrx for originally posting this:

Now eCrack stfu.

Either you're dilusional or just stupid. You didnt' post ANYTHING that proved me wrong... so either you STFU or you come make me STFU.... your choice e-toughguy. Have fun being wrong douchebag.

 

[haloweenhamster 10+ year member]

electrical is wiring (household electrics)

electronics is circuits (pcbs)

i test/repair black boxs down to component level (conventional & surfacemount)

what do u do thats usefull or relivant?

 

[midnightg35x 10+ year member]

A real EE would call himself an Electrical Engineer. Stop pretending.

In his defense, even IEEE stands for Institute of Electrical and Electronics Engineers.

That being said, I usually say EE is electrical engineer. Maybe that's because I am one...

 

[haloweenhamster 10+ year member]

BTEC Electrical & Electronic Engineering

HNC Electronic Engineering

HND Electronic Engineering

i even said electronics NOT EE

 

[FurbiesAndBeans 10+ year member]

In his defense, even IEEE stands for Institute of Electrical and Electronics Engineers.
That being said, I usually say EE is electrical engineer. Maybe that's because I am one...

hey midnight, how did those caps i sent u work out for u?

 

[smoka 10+ year member]

BTEC Electrical & Electronic EngineeringHNC Electronic Engineering

HND Electronic Engineering

Just noticed you are from UK, so I guess EE could mean different things over there....