Long term effects on batt/alternator from having a badass sound system?

[maxwinedog]

I read online that having a sound system is bad for the car cause you are putting an extra load on the electrical system, voltage and it will wear out your alternator and battery a lot faster? Is that true? Is it that hard on a car to run a nice sound system?

Sometimes i like to listen to music without the car running, so im guessing thats bad?

[Guillermo]

yes is true, which is why stereo ballers run heavy duty alternators and yellow top optimas.

[speedog]

OP needs to define nice sound system. If you're going to build something crazy, then you should be upgrading your vehicle's electrical system accordingly.

[crapstixs]

just get a capacitor for for your amp. and you will be fine.

[Cos]

Originally posted by crapstixs
just get a capacitor for for your amp. and you will be fine.

Not really, a cap is not a replacement for a battery. A cap maintains a certain amount of voltage, cleans up the signal, and helps restore a 1.00 PF. Subs (being inductive) cause a lagging power factor causing the amp and battery to draw more power than is required. It does also provide a more consistent power supply to the amp due to undersized power cable and voltage drop across that cable.

A cap is dangerous as it gets charged up but as I said a cap is not a replacement for a battery.


OP: yes your charging system can be permanently damaged if your system is too 'badass' also running the system with the car off (especially) for a long time can cause the life of the battery to be severely shortened and cause the alternator to have to re-charge a drained battery which is wasnt designed for.

[crapstixs]

Originally posted by Cos


Not really, a cap is not a replacement for a battery. A cap maintains a certain amount of voltage, cleans up the signal, and helps restore a 1.00 PF. Subs (being inductive) cause a lagging power factor causing the amp and battery to draw more power than is required.

A cap is dangerous as it gets charged up but as I said a cap is not a replacement for a battery.

it smothes out voltage spikes, making it easyer on your battery and alternator. you when the sub draws it will drian your cap first then go off your battery. but then again im no sterio expert.

[J-hop]

I was always under the impression that a cap would more or less save your battery and alt as when the bass hits hard it draws from the cap not straight from the battery/alt.

I used to run without a cap on my old car and when the bass hit you noticed a definite loading of the alt (apparent at idle) and sometimes a dimming of the headlights, but I later added in a cap and it completely eliminated this.

[crapstixs]

after doing some research, apparently your better off just wiring in another battery for your system. caps work but are very expencive, and batterys are better and cheaper. in my system the lights dim when the bass hits, its been like that for 2 years and i havent killed a battery yet.

[Cos]

Oh it does, it is a temporary source. However a cap is not a fix. No matter what you do the alternator will have to re-charge the cap or the battery.

If you have the odd hit then you may be okay. However if you are hitting all the time (like with a big system) then no matter how many caps or batteries the energy from that system has to come from the alternator.

[maxwinedog]

Originally posted by speedog
OP needs to define nice sound system. If you're going to build something crazy, then you should be upgrading your vehicle's electrical system accordingly.

Just basic deck, 400W amp, one 300W sub and basic amp kit.

Originally posted by Cos

OP: yes your charging system can be permanently damaged if your system is too 'badass' also running the system with the car off (especially) for a long time can cause the life of the battery to be severely shortened and cause the alternator to have to re-charge a drained battery which is wasnt designed for.

Is it expensive to change the alternator on a car? long big job? I know batteries are cheap to replace. Usually around $50 or so.

What is it in a sound system that draws so much power? the amp? sub? thats my guess.

Im guesisng if you just ran the deck and speakers it would be a lot easier on your alt/batt?

[J-hop]

Originally posted by crapstixs
after doing some research, apparently your better off just wiring in another battery for your system. caps work but are very expencive, and batterys are better and cheaper.

X-Cargo caps FTW.

[J-hop]

Originally posted by maxwinedog



Is it expensive to change the alternator on a car? long big job? I know batteries are cheap to replace. Usually around $50 or so.

What is it in a sound system that draws so much power? the amp? sub? thats my guess.

Im guesisng if you just ran the deck and speakers it would be a lot easier on your alt/batt?

really depends on how much room you have to work and where the alt is located. Its not something you want to be doing regularly.

the amp is what draws the power, but it will be a function of a few things. When you say 300w I am assuming this is the RMS rating of your amp? also how did you wire your sub up? the output will change depending on the resistance of your setup (ie: generally from my experience subs are either wired at 2 or 4ohms).

in general physics P=V^2 /R so with higher resistance = less power.


edit: actually to correct myself when I say resistance I should actually be saying Impedance because Amps output an AC signal and Resistance is for DC circuits (if I remember my elec. engg circuits course properly), however the same equation still applies (just with R=impedance)

[Cos]

Originally posted by maxwinedog


Is it expensive to change the alternator on a car? long big job? I know batteries are cheap to replace. Usually around $50 or so.

What is it in a sound system that draws so much power? the amp? sub? thats my guess.

Im guesisng if you just ran the deck and speakers it would be a lot easier on your alt/batt?

- Depends on the car. Alternators with core return are probably $250.00

- Depends on the car.

- Batteries CAN be cheap. Not all are. My truck battery is about $150.00

- It depends on the car. My truck has a 106A alternator.
P=IV so if you are running a 300w system at 14.4v that is 20A from your alternator alone. I think most car alternators are 60A to 80A. 20% to 30% increase just to run your amp on your alternator is quite the workout. I wouldnt go much bigger.

- The amp is what converts the signal from pure DC to a useable source for the actual sub so you can lump those together. Typically you can run a deck with no problems at all.

- Dont let me freak you out, i think with the stock system you have is probably adequate on your charging system. That being said I wouldnt go much bigger. When you said badass system I was expecting 2400W with duals and powered components.

- You have to pay to play, if you dont want additional maintenance leave the car as stock. Unfortunate truth to everything. You modify one thing you ARE giving up something else. This applies to pretty much everything. Rims/Tires, intake, ECU, stereo, etc. etc.

[maxwinedog]

Originally posted by J-hop


really depends on how much room you have to work and where the alt is located. Its not something you want to be doing regularly.

the amp is what draws the power, but it will be a function of a few things. When you say 300w I am assuming this is the RMS rating of your amp? also how did you wire your sub up? the output will change depending on the resistance of your setup (ie: generally from my experience subs are either wired at 2 or 4ohms).

My mech just checked my alt. this afternoon cause my batt was toast (froze overnight) and I had to get a new battery today. I cant even remember when i last changed that battery but it was many years ago haha.

Im running 4ohms, all 4 speakers are running to the deck, sub off a 400W kicker 4ohm mono amp. I was told 4ohm is better cause its a lot less power than 2ohm. Not sure exactly on the cables but its a pretty good quality amp kit i got. Yes Amp is 400W rms and sub is 300W rms.

Originally posted by Cos
- if you are running a 300w system at 14.4v that is 20A from your alternator alone. I think most car alternators are 60A to 80A. 20% to 30% increase just to run your amp on your alternator is quite the workout. I wouldnt go much bigger.

- The amp is what converts the signal from pure DC to a useable source for the actual sub so you can lump those together. Typically you can run a deck with no problems at all.

- Dont let me freak you out, i think with the stock system you have is probably adequate on your charging system. That being said I wouldnt go much bigger. When you said badass system I was expecting 2400W with duals and powered components.

- You have to pay to play, if you dont want additional maintenance leave the car as stock. Unfortunate truth to everything. You modify one thing you ARE giving up something else. This applies to pretty much everything. Rims/Tires, intake, ECU, stereo, etc. etc.

My amp is 400W RMS and sub is 300W RMS. If I can find a deal on a 300W RMS amp id probably get it and sell my 400W just to be less stress on the alt. I was going to get components for the fronts but then id have to get another amp for them and didnt want to get into that. And thats another reason why i didnt want to run more than 1 sub.

So basically if i removed my amp and sub and just ran my deck + aftermarket coax speakers, that would pretty much be 0 load on the alt?

[J-hop]

what amp are you running? I am going to say at 4 ohms your amp should output closer to 200w RMS, the 400w RMS is probably at 2ohms I am guessing?

I just can't see too many shops overpowering a sub like that.


edit: when I say which amp i mean model number, zx400 possibly?? this one is rated at 200w rms at 4ohm impedance

[Cos]

Originally posted by maxwinedog




My amp is 400W RMS and sub is 300W RMS. If I can find a deal on a 300W RMS amp id probably get it and sell my 400W just to be less stress on the alt. I was going to get components for the fronts but then id have to get another amp for them and didnt want to get into that. And thats another reason why i didnt want to run more than 1 sub.

So basically if i removed my amp and sub and just ran my deck + aftermarket coax speakers, that would pretty much be 0 load on the alt?

I wouldnt worry THAT much about it. You could probably run 5/600 safely. Just dont go up on the sub.

Components can be run off the deck, unless your sub is HUGE you should be okay.

[maxwinedog]

Originally posted by J-hop
what amp are you running? I am going to say at 4 ohms your amp should output closer to 200w RMS, the 400w RMS is probably at 2ohms I am guessing?

I just can't see too many shops overpowering a sub like that.


edit: when I say which amp i mean model number, zx400 possibly?? this one is rated at 200w rms at 4ohm impedance

Kicker 10ZX400 Class D mono amp. CRAP i just realized it says 400W RMS 2ohm amp. SO how can i find out forsure if my sub is wired as 4 or 2ohms? It looks like my amp is 2ohms only...let me google the specs some more.

http://www.crutchfield.com/p_20610ZX...ures_and_specs

But what I was told, is that right though? Sub wired up as 4ohm uses less power than 2ohm hookup?

[maxwinedog]

I got another question for who ever can answer it - TIA!

I need a longer speaker wire going from the amp to sub, can i just use reg speaker wire used for my home audio? or does it have to be car speaker wire (not sure if theres even such a thing). i run 14gauge wire in my house.

and the current wire now it goes into my amp with RCA like outputs at the end of the wire. how do i add the RCA lkke outputs to reg speaker wire?

[Jetta-2.0]

from the amp to the sub a 14g should be ok, the most importaint thing is from ur amp to ur batt

[copynpaste]

I hate to break it to you OP but I personally wouldnt run a 400W RMS amp on a stock alternator. Stock alternators are not rated for continuous duty. In other words a stock type 140 amp alternator can only output full power for a short period of time. this is how they are designed and. that is a maximum rating at a certain rpm etc. If you are pulling a lot of power from the battery to the point where the alternator is having to work hard for long periods of time. they will overheat. They can also go into saturation where they simply go wide open and the voltage go up to 16volts. then they cook the battery and you start an endless cycle of replacing batteries and alternators. Stock alternators just weren't designed with big big car stereo systems, where you have a large constant current draw, in mind. they were designed for the short large current draws like from a starter motor and a smaller constant current draw over time.

If I were you I would either

1) Downsize your amp to say a 200W or less one or

2) Upgrade your alternator to aftermarket high capcity

Personally I would do 1, itd be considerably cheaper since you wont have to pay a mech to change the alternator and you could get some money back on your current amp.