Subwoofer in car... electrical question

[AgaBoogaBoo]

I've always kept away from having a subwoofer in my car, but I'm starting to think about it, with my only concern being the electrical setup.

I've always thought of a subwoofer as something that would put strain on the alternator because of the constant changes in how much power it draws. It just never made sense to me how this would work, but when I think about it, I guess the solution would be to get a capacitor.

I planned on getting a 10" driver and building an enclosure for it - I have an 08 Civic and it probably won't need much more than that. I'm not trying to hit 20hz with this either.

Any thoughts? Has my worry just been in my head and it isn't something to worry about?

 

[Budmantom]

Originally posted by: AgaBoogaBoo
I've always kept away from having a subwoofer in my car, but I'm starting to think about it, with my only concern being the electrical setup.

I've always thought of a subwoofer as something that would put strain on the alternator because of the constant changes in how much power it draws. It just never made sense to me how this would work, but when I think about it, I guess the solution would be to get a capacitor.

I planned on getting a 10" driver and building an enclosure for it - I have an 08 Civic and it probably won't need much more than that. I'm not trying to hit 20hz with this either.

Any thoughts? Has my worry just been in my head and it isn't something to worry about?

Yes, its all in your head.

 

[BlackTigers]

Originally posted by: AgaBoogaBoo
I've always kept away from having a subwoofer in my car, but I'm starting to think about it, with my only concern being the electrical setup.

I've always thought of a subwoofer as something that would put strain on the alternator because of the constant changes in how much power it draws. It just never made sense to me how this would work, but when I think about it, I guess the solution would be to get a capacitor.

I planned on getting a 10" driver and building an enclosure for it - I have an 08 Civic and it probably won't need much more than that. I'm not trying to hit 20hz with this either.

Any thoughts? Has my worry just been in my head and it isn't something to worry about?

Most people don't switch over to the high-output alternators until they get into the thousands of watts range. If you're feeling frisky, you can try this for some extra stability. I've done it to three cars without problems.

I've also dropped two 12" subs with a 1500W RMA amp into a car on the stock alternator, and It was fine.

 

[marincounty]

I read somewhere that Richard Clark, one of the gurus of car audio, doesn't even recommend beefy alternators anymore.

I would just use a cap and you should be fine.

And your 10" woofer should hit 20 Hz just fine in your car.

 

[BassBomb]

Average 10" woofer won't do 20Hz

You will be fine, use a capacitor if you are worried. The main thing is don't use the subwoofer too much with the engine off, because then you will lose starting power for your car.

A 10" subwoofer will not drain significant amount of power (unless its like 600w RMS)

 

[BlackTigers]

Why use a capacitor? Everything (I mean everything) I've read recommends against them, as what they do is rather insignificant for the cost, and a second battery would be so much more beneficial. All I'm reading is that caps are simply a short-term cover for a bigger problem.

Either upgrading your battery, or adding another would do wonders more than a capacitor. That said, I've run 2000w on a stock alternator/battery setup with no dimming issues.

 

[95SS]

Take the money for a cap and do the Big 3, as mentioned. You should have no problems running ~500Wrms on a stock electrical system with Big 3. I'll be running about 2000wrms (rated), and have no plans for a HO alternator. Just a good front battery, and a second in the back.

Another question, what are you looking at for sub and amp? What kind of enclosure? How much trunk space are you willing to lose?

 

[alkemyst]

Originally posted by: marincounty
I read somewhere that Richard Clark, one of the gurus of car audio, doesn't even recommend beefy alternators anymore.

I would just use a cap and you should be fine.

And your 10" woofer should hit 20 Hz just fine in your car.

huh, what....

I am hoping you are being sarcasic, but in a thread like this it only comes off as you really looking like an idiot.

For alternator level, you need to go by how many amps you are drawing with all accessories and you stereo at the level you want. Once you know that you can find out if you can handle it or need to go higher. The 'fuse' rating of your amp is not really a good indicator.

 

[marincounty]

Originally posted by: alkemyst

Originally posted by: marincounty
I read somewhere that Richard Clark, one of the gurus of car audio, doesn't even recommend beefy alternators anymore.

I would just use a cap and you should be fine.

And your 10" woofer should hit 20 Hz just fine in your car.

huh, what....

I am hoping you are being sarcasic, but in a thread like this it only comes off as you really looking like an idiot.

For alternator level, you need to go by how many amps you are drawing with all accessories and you stereo at the level you want. Once you know that you can find out if you can handle it or need to go higher. The 'fuse' rating of your amp is not really a good indicator.

CURRENT AND EFFICIENCY
By Richard Clark

"High Output" Alternators

As anyone that reads our newsletter knows, we are categorically against upgrading alternators. Seldom are they really needed. More often than not, changing alternators causes secondary problems related to the function of the vehicle. As cars become more and more complicated and charging systems become
even more integrated into the vehicle, "upgrading" alternators may not even be possible. Only a few short years ago large alternators and multiple batteries were the norm in high-end car audio. These electrical behemoths were usually connected together with another unnecessary product. This device was the diode isolator. From the very first issue of A2TB, we took a hard stand against electrical systems built
around so called "high output alternators," second batteries, and diode isolators. Nevertheless, in an industry that is slow to accept change we feel that our influence has been positive. Most large car audio systems of today rarely include larger alternators and more than two batteries. And the device that was designed to work in campers and RVs, the diode isolator, has all but disappeared from car audio. Only
the technically unenlightened still adhere to these antiquated techniques.

Text

You know you really are an idiot if you think you know more about car audio than Richard Clark. This guy practically invented modern car audio.

And your 10" woofer should easily hit 20 Hz IN CAR in a sealed box.

 

[alkemyst]

you really misunderstood the point of that article. It's more about running to swap to a bigger alternator shouldn't be the first steps anymore. He also talks alot about caps.

Also anyone that knows anything about audio in general knows getting to 20Hz isn't hard esp in a car, but at what level. Not all 10" subs are capable of this, you don't even know what he is using nor what sized box he can do.

I have two of these: http://www.imagedynamicsusa.com/manuals/iD/ID10D2v3.pdf

 

[TechBoyJK]

Originally posted by: marincounty

Originally posted by: alkemyst

Originally posted by: marincounty
I read somewhere that Richard Clark, one of the gurus of car audio, doesn't even recommend beefy alternators anymore.

I would just use a cap and you should be fine.

And your 10" woofer should hit 20 Hz just fine in your car.

huh, what....

I am hoping you are being sarcasic, but in a thread like this it only comes off as you really looking like an idiot.

For alternator level, you need to go by how many amps you are drawing with all accessories and you stereo at the level you want. Once you know that you can find out if you can handle it or need to go higher. The 'fuse' rating of your amp is not really a good indicator.

CURRENT AND EFFICIENCY
By Richard Clark

"High Output" Alternators

As anyone that reads our newsletter knows, we are categorically against upgrading alternators. Seldom are they really needed. More often than not, changing alternators causes secondary problems related to the function of the vehicle. As cars become more and more complicated and charging systems become
even more integrated into the vehicle, "upgrading" alternators may not even be possible. Only a few short years ago large alternators and multiple batteries were the norm in high-end car audio. These electrical behemoths were usually connected together with another unnecessary product. This device was the diode isolator. From the very first issue of A2TB, we took a hard stand against electrical systems built
around so called "high output alternators," second batteries, and diode isolators. Nevertheless, in an industry that is slow to accept change we feel that our influence has been positive. Most large car audio systems of today rarely include larger alternators and more than two batteries. And the device that was designed to work in campers and RVs, the diode isolator, has all but disappeared from car audio. Only
the technically unenlightened still adhere to these antiquated techniques.

Text

You know you really are an idiot if you think you know more about car audio than Richard Clark. This guy practically invented modern car audio.

And your 10" woofer should easily hit 20 Hz IN CAR in a sealed box.

you might hit 20Hz with a 10" sub, maybe. And that depends on the sub. Even then the slope will be so degraded compared to the 35-45hz range that it won't even be noticeable. So NO, your 10" will not hit 20hz in a way that matters.

 

[AMCRambler]

Got a 12inch Kappa perfect with a 600w amp running in my car with the stock alternator. It definitely made the headlights dim when the sub hit. Went out and got a half farad cap, should have gone for the 1 farad but I was cheap. That helped a bit but still dimmed the lights when I cranked it up. So I picked up an Optima yellow top. That solved the dimming issue for good.

 

[alkemyst]

many keep bringing up size of the sub, but it's really just a matter of how much amps you are pulling with the amp.

With dimming and the like usually the first avenues are making sure the charging system is working, having a good battery and making sure you are supplying the proper wiring to the amp and ground.

This alone solves most problems.

Then a cap can be added if you are marginal. I did and my lights don't dim anymore...so it worked for me.

After all that then the alternator can be increased.

Now technically my alt is rated at 90amps, my amp can draw up to 90amps. I never listen to it that loud though.