Amplifier and Alternator Loads

[Seraphitia102]

I talked to a car stereo specialist at Best Buy and I was interested in a Pioneer 4 channel 760 watt amp. I asked if I needed to get a capacitor. He said since I'm making less than 1000 watts of power, I wouldn't need a capacitor.

He said that the amplifier drains power from the battery while the alternator recharges the battery. He also said that since I have an Optima battery, I really don't need a capacitor.

What do you guys think? Should I get at least a half-farad capacitor just to be on the safe side? Or is really unecessary?

 

[KidCapri50]

I would get the capacitor.

 

[sgarlic]

Capacitors just basically store energy for when it isn't available.. they don't store enough to give your alternator a break really. If you're thinking of running a high power setup, you may want to think about upgrading btoh your alternator (PA Performance makes a nice 200amp model with a lifetime warranty,) and battery (Optima dry cell of some sort.)

Just FYI, my foxbody ran over 1,000 watt amp, and I never had a capacitor.. just a 130 amp alternator and an Interstate battery.. you should be fine without one for your setup.

 

[DropTopPony]

You should be fine without a cap in your car. The stock alt is 130 amps and will last a long time. I was running 1200 watts rms for over 5 years on the stock alt/battery combo. I did eventually upgrade to a PA 200 amp alt from steeda and a optima battery. I have a 1F cap that i have from another system in my car but i don't think i need it with my current JL amps. Newer amps have enough capacitance that you don't really need external capacitors unless you are running high current SPL setups. If you want it for piece of mind then go for it but you don't need it.

 

[sgarlic]

I thought the stock alts on 99-04 were 110?

 

[DropTopPony]

I thought the stock alts on 99-04 were 110?

I'd assume they were the same as mine which was 130, i hope they wouldn't downgrade.

 

[SUPRCHRGD302]

You don't need a cap for amplifiers running speakers. They don't get that much of a lode put on them. You only need them on amplifiers running subs. They store power for the amplifier when it's hitting those hard low notes (when it's really drawing current) to give it a constant source of power. You'll be fine without one for that 4 ch. amp.

 

[Seraphitia102]

Thanks, I appreciate your input. I really don't want to spend extra money on a capacitor... I have an Optima Red Top battery, besides their durability, do they hold like an extreme amount of power over a regular battery?

 

[trinity_gt]

As sgarlic pointed out, a capacitor is an energy storage device. It's intended to supply the amplifier under heavy transient load conditions, like when a bass hit comes, when the rest of the electrics can't do it. A car battery possesses a ton of stored energy as well but to get this power to the amp requires running the current through the internal resistance of the battery and feet and feet of cable. The cap, placed close to the amp, provides a sizeable store of juice right where it's needed and can provide that power "right now."

The need for a cap in your system really depends on how hard you want the bass to hit, how big your amp is, how big the bass drivers are, how big the power cable is running to the amp(s) and how long they are, etc.

 

[wannabe2000GT]

i have a capacitor that i will sell you for $20. i had it in my last car for about 4 months and it works good. if you want it let me know.

 

[DropTopPony]

Thanks, I appreciate your input. I really don't want to spend extra money on a capacitor... I have an Optima Red Top battery, besides their durability, do they hold like an extreme amount of power over a regular battery?

They are stronger then most stock batteries (cca @800) but what really makes them better is the ability to recharge them over and over. My car will sit sometimes for a month so i just pop on the slow charge the day before i need it and it will fully charge the optima up like it never died. If i drive it every few days it never dies.

 

[Seraphitia102]

i have a capacitor that i will sell you for $20. i had it in my last car for about 4 months and it works good. if you want it let me know.

have any pictures of the capacitor?

 

[Seraphitia102]

They are stronger then most stock batteries (cca @800) but what really makes them better is the ability to recharge them over and over. My car will sit sometimes for a month so i just pop on the slow charge the day before i need it and it will fully charge the optima up like it never died. If i drive it every few days it never dies.

I have the Red Top 75/35 battery with 720cca (cold cranking amps?). I just heard they were really great batteries so I just had to get one.

 

[DropTopPony]

I have the Red Top 75/35 battery with 720cca (cold cranking amps?). I just heard they were really great batteries so I just had to get one.

eh, they are good. I'm, on my 3rd red top. First one lasted 3 yrs...2nd lasted 2 months(replaced under warranty) i'm on the 3rd and if this one goes i'll replace it with a Yellow Top since that one is better for cars that don't get driven daily.

 

[thomas91169]

id get one anyways. youd be suprised how big of a difference it makes for the amp.

ill put it to you this way. i have a 1300W audiobahn amp running a single Eternal 12" sub. i was getting major clipping, when i tried to turn the bass up, the knob(its a remote bass knob, turns red when its capping, blue the rest of the time) would turn red and the sub sounded like ass. so my freind says "d00d you need a cap". so i call up my audiobahn guy and tell him, and hes like "the theory goes, you should have 1farad of caps per 1000watts, but, in reality, you should have 1farad per 500watts to be on the safe side". so i hop on ebay, order 2 1farad audiobahn caps and hook them up. holy ****, i can turn that **** up, and the knob doesnt hit blue at all.

caps are wired in Line, so it goes: Battery, C1, C2, Amp
Cap 1(closest to battery) shows 13.4 at almost all times but constant bass, in which it might drop to 13.2.
Cap 2(closest to amp) shows 13.0 when bass is hitting on and off. when bass is hitting constant, it might drop to 12.8. remote knob never hits in the red, and i havent even raised it yet, its still at 1/4 bass. and this setup hurts the ears, right now it makes me sneeze at moderate levels of showing off to gangsters in 26" spinnerd escalades who think a little mustang cant outbeat their 4 solobarics and crappy retail store equipment.http://www.cardomain.com/ride/2090686/4 before the cap install, http://www.motechracing.com/forum/attachment.php?attachmentid=93&stc=1
http://www.motechracing.com/forum/attachment.php?attachmentid=95&stc=1 (car on, stereo off, 14v)

id go with at least one. itll provide a more stable power to the amp, which your amp will love you for, and hop on ebay, cause caps are 20 bucks for a nice one on there, whereas best buy will rape you 100 bucks for a ****ty one.

 

[Seraphitia102]

id get one anyways. youd be suprised how big of a difference it makes for the amp.

ill put it to you this way. i have a 1300W audiobahn amp running a single Eternal 12" sub. i was getting major clipping, when i tried to turn the bass up, the knob(its a remote bass knob, turns red when its capping, blue the rest of the time) would turn red and the sub sounded like ass. so my freind says "d00d you need a cap". so i call up my audiobahn guy and tell him, and hes like "the theory goes, you should have 1farad of caps per 1000watts, but, in reality, you should have 1farad per 500watts to be on the safe side". so i hop on ebay, order 2 1farad audiobahn caps and hook them up. holy ****, i can turn that **** up, and the knob doesnt hit blue at all.

caps are wired in Line, so it goes: Battery, C1, C2, Amp
Cap 1(closest to battery) shows 13.4 at almost all times but constant bass, in which it might drop to 13.2.
Cap 2(closest to amp) shows 13.0 when bass is hitting on and off. when bass is hitting constant, it might drop to 12.8. remote knob never hits in the red, and i havent even raised it yet, its still at 1/4 bass. and this setup hurts the ears, right now it makes me sneeze at moderate levels of showing off to gangsters in 26" spinnerd escalades who think a little mustang cant outbeat their 4 solobarics and crappy retail store equipment.http://www.cardomain.com/ride/2090686/4 before the cap install, http://www.motechracing.com/forum/attachment.php?attachmentid=93&stc=1
http://www.motechracing.com/forum/attachment.php?attachmentid=95&stc=1 (car on, stereo off, 14v)

id go with at least one. itll provide a more stable power to the amp, which your amp will love you for, and hop on ebay, cause caps are 20 bucks for a nice one on there, whereas best buy will rape you 100 bucks for a ****ty one.

Yeah I guess maybe I wanna get a half farad or one farad if the price is right I'm saving my money for a Vortech SQ so I'm limited in options.