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Is a cap worth it ?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=37460
Printed Date: March 28, 2024 at 5:07 AM


Topic: Is a cap worth it ?

Posted By: vdubmk4
Subject: Is a cap worth it ?
Date Posted: August 15, 2004 at 11:01 PM

Is purchasing a cap worth it ? I was always under the impression that a cap was only needed if ur lights dimmed on big hits or if your amp wasnt puttin out enough rms for the subs ? Sorry i'm newbish in the cap area.



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Fortune: You will continue to take chances, and be glad you did.



Replies:

Posted By: cd2478
Date Posted: August 15, 2004 at 11:06 PM

an amp is just a cheap workaround to the fact that your electrical system is not up to the task of powering your stereo setup..

if you are having power delivery issues and have got the correct cabling and the power just isnt there, put the money towards a bigger amp and alternator, it will be better spent than going towards a cap

a cap can sometimes help, depending on how bad your problem is, if its minor as in just lights dimming then yeah a cap would be good. if its more than minor a cap will not eliminate the problem.

do you even have any issues with your stereo? if it goes fine and ru car goes fine, dont worry about one ;)





Posted By: vdubmk4
Date Posted: August 15, 2004 at 11:08 PM
Nope, my car works excellent. I was just curious, Thanks for the info though.

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Fortune: You will continue to take chances, and be glad you did.




Posted By: MBZ oe
Date Posted: August 15, 2004 at 11:21 PM

If you are running some serious equipment, then a cap will always help. Rockford Fosgate has some new BIG caps out that are pretty nice for the money. 50+Farads.

Also check out batcaps by X-static. I have only heard good things about them.



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BOOM, BOOM, BOOM BOOM....




Posted By: auex
Date Posted: August 15, 2004 at 11:29 PM
IMO it is not worth buying a 1 or 2 farad cap.

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Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.




Posted By: MBZ oe
Date Posted: August 15, 2004 at 11:32 PM
I agree with you AUEX

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BOOM, BOOM, BOOM BOOM....




Posted By: vdubmk4
Date Posted: August 15, 2004 at 11:36 PM
Sweet Jesus, 50+ farads, thats craazy.

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Fortune: You will continue to take chances, and be glad you did.




Posted By: cd2478
Date Posted: August 16, 2004 at 12:10 AM
around 50,000 watts for 50 farad cap???? damn...i dont think theres too many systems in australia with that sort of power lol. or even hardware that can support that much power! wow




Posted By: Caraudiorich
Date Posted: August 16, 2004 at 9:55 PM
Me,  I would recomend a second batery.   But thats me,  from experience.




Posted By: speedwayaudio1
Date Posted: August 17, 2004 at 3:57 AM
 a cap will do nothing for you if you don't have the ho alt to power it. now if you got the power then a cap will help on the hard bass hits. and a second batt will not help if you don't have the ho alt for it. they both will just make your stock alt work harder. get a high output alt, then get the other stuff  if you want you be glade you did. I run a 250 amp ac/delco alt, 2- 1000amp dura last batts and a 400amp 6 farad battcap. It all comes together very nice.

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Big Dave




Posted By: customsuburb
Date Posted: August 17, 2004 at 8:37 AM
A second battery will only let you run your system longer with the car off, or let you drain the second battery with the car off and your system playing instead of draining your main battery (so you can start your car).

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Posted By: DYohn
Date Posted: August 17, 2004 at 10:29 AM
IN GENERAL, Caps are a waste of money for most people.  So are extra batteries.  If you want to power a large system, a high-output alternator is the only solution that works.

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Support the12volt.com




Posted By: azidrane
Date Posted: August 17, 2004 at 1:58 PM

I dont understand all of this CAP bashing. A cap is for holding onto large amounts of power to be used when the system needs to peak (eg, a large bass hit). Without this, when the amp needs the extra power, it has to get it directly from the battery. A battery is a device that is made for longterm slow power output, not really up to the task of delivering large amounts of power on demand. A cap on the other hand is short term power  holding for very fast dissapation. Which is kinda what you want when the amp says "gimme some power, i gotta make some bass". I dont know what you guys have been running in your systems, but i run atleast 2 one f caps on a 600 watt rms amp Every time. and it make a HELLA difference in bass responce and distortion reduction.

thats my take.





Posted By: switch_hitter
Date Posted: August 17, 2004 at 2:02 PM

They arent saying caps dont work, but they are band aids for electrical systems with not enough power...How much is a 1 farad cap retail these days..like $150 - $200 beans?  You can add a couple more dollars to that and get a high output alternator and solve all your problems..



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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: azidrane
Date Posted: August 17, 2004 at 2:02 PM

I don’t understand all of this CAP bashing. A cap is for holding onto large amounts of power to be used when the system needs to peak (e.g., a large bass hit). Without this, when the amp needs the extra power, it has to get it directly from the battery. A battery is a device that is made for long-term slow power output, not really up to the task of delivering large amounts of power on demand. A cap on the other hand is short term power holding for very fast dissipation. Which is kind of what you want when the amp says "gimme some power, I gotta make some bass". I don’t know what you guys have been running in your systems, but I run at least 2 one f caps on a 600 watt rms amp every time. and it makes a HELLA difference in bass response and distortion reduction.

That’s my take.

 





Posted By: azidrane
Date Posted: August 17, 2004 at 2:22 PM
switch_hitter wrote:

They arent saying caps dont work, but they are band aids for electrical systems with not enough power...How much is a 1 farad cap retail these days..like $150 - $200 beans?  You can add a couple more dollars to that and get a high output alternator and solve all your problems..


Yes, a high output alternator would help out allot by putting more power into the circuit, but does it solve the problem of quick high power consumption by the amps? This is one thing that sets most amps apart from others is their amount of power capacity built in. Isn’t it obvious that by adding an external cap, their would be no more problem with power deficiencies?





Posted By: switch_hitter
Date Posted: August 17, 2004 at 2:34 PM

Caps can help out a system greatly, but in my opinion the correct approach would be to get an alternator, and then a cap....if needed....but you are right about them helping when there are quick high power draws ...but they dont necessarily "solve power deficiencies".



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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: azidrane
Date Posted: August 17, 2004 at 2:38 PM

Good point. I agree.

Where can one find a Hi output alternator and what defines a Hi output alternator?





Posted By: switch_hitter
Date Posted: August 17, 2004 at 2:45 PM
You can search on Ebay, thats where i bought mine. Sometimes you call around to local shops that deal with alternators and you can get them to "deuce" yours up... (add more copper coil) which increases the output. Only bad thing about this route is normally the shop won't warrantee the work. Personally i define Hi Output as 200amps and above...

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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: promodeepcycle
Date Posted: August 17, 2004 at 2:46 PM
actually a cap will help you to lose 1-1.5 db ... if you want an honest answer... what are you running.. ? and in what car .. where are the amps.? what size cabling? notice you dont see caps in db cars. ?"spend 150$ on a cap or 150 on a batt.?  let me hear what you got..

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dont be a pet monkey ..use your dmm




Posted By: switch_hitter
Date Posted: August 17, 2004 at 2:48 PM
You also lose voltage when using an isolator, i think like half a volt.

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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: greenbroncoguy
Date Posted: August 17, 2004 at 4:31 PM

ok, all of you guys that say caps don't help, answer me this:

I have a 240 amp alternator, 2 Optima Yellow top batteries, 2ga. wiring to my 1000watt amp that is pushing 412"s, and my headlights still dim.

This is in an old (1979) bronco with not very many electronics to speak of that would also be draing power. Noone thinks a cap would help???





Posted By: customsuburb
Date Posted: August 17, 2004 at 4:40 PM

Take a voltage reading at your amplifier. Does your bass start out clean and crisp and then turn to mush? Do your headlights only dim at the beginning of a bass note and then go back to normal level, or do they dim for the entire bass note? To test this park your bronco in front of a wall or garage door at night and play a song that has long bass notes. Then look at your headlights and see if they dim through the whole bass note or just at the beginning. If just at the beginning then a cap might help you a little.



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Posted By: greenbroncoguy
Date Posted: August 17, 2004 at 4:54 PM
no, my lights dim all the way through the entire bass note, and they dim really badly.




Posted By: customsuburb
Date Posted: August 17, 2004 at 6:35 PM
Is this at idle? Again, I'm curious to see what the voltage reading is at your amp.

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Posted By: DYohn
Date Posted: August 17, 2004 at 7:16 PM

A capacitor can certainly help in the ways it was intended: to help compensate for the short duration dips in voltage caused by high current draw.  This is called a ripple filter, and is what caps do best.  But no capacitor can help if your alternator cannot supply the current demand.  The voltage dip during long musical passages is often too severe and lasts too long for the short discharge duration of even the largest caps to have much effect, and then your discharged capacitor will place additional load on the alternator and electrical system as it attempts to charge back up.  The alternator is the primary source of power in a running vehicle with a properly operating voltage regulator.  A cap is a band-aid for a short-duration transient voltage issue and is intended to help the amplifier sustain its output, it is never a solution for an overloaded electrical system and it will generally have very little effect on dimming lights.

Greenbroncoguy, your system has a problem.  Something is not operating properly or is not setup properly, or you are simply not getting the output required from your alt.  As customsuburb asked, what is the voltage at your amplifier?  I suspect your engine is not turning fast enough for the alternator to produce the current required.  Or you have a bad belt or something.   Remember that an alternators max output (in your case 240 amps) is the rating ONLY when it is being turned at its optimum RPM by your engine.



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Posted By: greenbroncoguy
Date Posted: August 17, 2004 at 7:47 PM

I haven't checked the voltage at my amp yet, I will tomorrow as it is storming now (typical Florida weather).

As to my alternator, after I bought it new, I had it checked and the dude printed the specs out and were as follows: 248 amps @ 5000 rpm : 167 amps @ 3500 rpm : 101 amps @ 2500 & about 90 amps @ about 800 rpm. I say about because I have a bigblock engine with a very large cam and it idles erratically. However, my lights dim when I am driving down the road also, not only at idle when it is much worse. Since I have a bigblock and will hardly ever turn it above 6500, they put a smaller pulley on the alternator to make it charge more at a lower rpm. So, I dont think my alternator is the problem.  Also, my belts are new and I keep them tight so I can probably rule that out also.





Posted By: promodeepcycle
Date Posted: August 17, 2004 at 8:13 PM

have you upgraded your grounds?... next  is the wire from your alt. to your batt. 2 awg? 3rd how long is the 2 awg run from alt. to your last batt.?

you need to have 2 awg grounds from your alt. to your frame. 2 awg from your batt's. to your body at least and 2 awg from the body to the frame..



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dont be a pet monkey ..use your dmm




Posted By: greenbroncoguy
Date Posted: August 17, 2004 at 8:20 PM

My wire sizes are:            

               both grounds from both batteries to the frame are 0/1 ga.:  the wire from my alt. to both batteries is 2ga. , the short one is about 2 feet long, and the long one is about 5 feet: I don't have any grounds that go directly from my battery terminals to my body, but I have alot of ground straps throughout my truck that go from my body to my frame, I added like maybe 10, and there were already maybe 10 more.





Posted By: greenbroncoguy
Date Posted: August 18, 2004 at 4:15 PM
I cheacked the voltage at my amp today, and with the truck not running, the voltage was 12.6 volts at the battery, and 12.3 volts at the positive connection at my amp. With the truck running at idle, the power at the battery was about 13.9 volts, and at the positive connection on my amp it was 13.7. With the truck idled up, the power at the battery was 14.6volts, and at the amp it was also 14.45volts. It seemds to me that all my power is good at my amp.




Posted By: DYohn
Date Posted: August 18, 2004 at 4:28 PM
Are those voltage readings with your system running or off?  If your lights are dimming while you get those voltage readings, there is something wrong with your vehicle not related to the audio system.  If those voltage readiongs are with the system off, it's not telling us anything useful I'm afraid.

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Posted By: greenbroncoguy
Date Posted: August 18, 2004 at 4:45 PM
i posted the reading for both on and off, it says in my post which readings are with the system off and on.




Posted By: stevdart
Date Posted: August 18, 2004 at 5:04 PM
...not the way it reads...

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: greenbroncoguy
Date Posted: August 18, 2004 at 6:05 PM

oh, sorry... :  )

that is with my system on, but not with the bass hitting.





Posted By: DYohn
Date Posted: August 18, 2004 at 6:16 PM
So take some readings with your bass "hitting."  Otherwise, you're not putting much of a load on your electrical system.  And were your lights dimming when you took your first set of readings?

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Support the12volt.com




Posted By: racer427
Date Posted: August 18, 2004 at 6:28 PM
switch_hitter-------- Where on E-Bay did you find your alternator?

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Alpine CDA-9833 HU
Diamond Audio M661 Components
MTX Thunder T6.6 Components:rear fill:
Cadence Q400 4 Channel Mains + rears
Thunder 801D Subs
MTX 1004 10's
Dual 4g wire to rear
4g grounds




Posted By: greenbroncoguy
Date Posted: August 18, 2004 at 6:29 PM

ok, I will take more...

No, if my system is off, my lights do not dim, even with all of this on: my electric fan (35amps), my blower motor (20amps), all four headlights (50amps-I have 2 stock and two fullsize ones built into my custom front bumper), electric fuel pump (10 amps), & high-output MSD ignition (10amps). Looks like all of that adds up to be 125 amps, no where near what my alternator is capable of charging at. Also, I never run my blower motor b/c I have taken out my a/c and my heater hoses aren't even hooked up, & I hardly ever run my extra set of lights in my bumper, so that should take away 45amps right there, so I am only pulling about 80 amps under normal driving conditions when my lights are dimming.





Posted By: greenbroncoguy
Date Posted: August 18, 2004 at 6:32 PM
I did not buy my alternator from ebay. I bought it from a reputable early Bronco specialty supplier where they deal only with trucks like mine. I can assure you that my alt. isn;t the problem, because with all the stuff on that I mentioned above (with no system on mind you), at 1200rpm, my voltage reading at the battery is a constand 14.7v.




Posted By: switch_hitter
Date Posted: August 18, 2004 at 9:35 PM
what type of vehicle is the alternator for Racer?

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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: switch_hitter
Date Posted: August 18, 2004 at 9:44 PM
heres the stores' site...   motorcityreman.com

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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s




Posted By: racer427
Date Posted: August 19, 2004 at 3:06 PM
Switch, it is for a lumina APV. I am running 4g with a 60 amp inline fuse to a dstra block and 8g to the amp. On heavy hits the lights dim. So will probably need at least a 150 amp alt.

-------------
Alpine CDA-9833 HU
Diamond Audio M661 Components
MTX Thunder T6.6 Components:rear fill:
Cadence Q400 4 Channel Mains + rears
Thunder 801D Subs
MTX 1004 10's
Dual 4g wire to rear
4g grounds




Posted By: switch_hitter
Date Posted: August 19, 2004 at 7:39 PM

motorcityreman.com sells a 160 amp alternator for a 94-97 Lumina 3.1-3.4L for $169.99  check it out



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2 Memphis HPO 12s
1 Memphis 1000D
2 Memphis 8s
1 Memphis MC200
4 Memphis 3way 6 1/2s
1 Memphis MC3004
4 Memphis Tweeters
1 Memphis 3-way electronic crossover
2 Memphis 5 1/4
2 Memphis 4s





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