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[chase297 10+ year member]

Would I need to replace any electrical stuff in my car (1992 acura legend) if I was going to run a lanzar 400 x 2 amp. Would I need a capacitor? Thanks.

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[Randy Savage 5,000+ posts]

What are the specs on the amp? RMS? What are you running to, and at what impedance?

 

[MikeofTulsa Moderator]

also how many ampers does your current alt put out???

 

[80_Cutlass_mn 10+ year member]

I dont think youll have to worry about that lanzar amp pulling more than what your alt can put out cuz they arent very good amps(from what ive heard). IMO I think youll be allraight

 

[chase297 10+ year member]

the amp puts out 400 watts x 2 and thats a two 2 ohm loads. Not to sure what my alternator puts out though, how could I find out?

 

[MikeofTulsa Moderator]

most of them put out what they are rated at on the alt...mine is a 90amp alt.......so ur running aprox 800 total watts......800w/14.4v = 55.5ampers.....that amp will draw aprox 55 ampers max if it was 100% effecient....i'm goin to say its anywhere from 60-80% effecient....so your looking at 33-44ampers of current max

 

[chase297 10+ year member]

so would I need a capacitor or any new electrical components?

 

[rco8786 10+ year member]

Originally posted by chase297 so would I need a capacitor or any new electrical components?

You should be fine. But put the amp in, and if your lights dim..then you may look into an alt upgrade.

 

[Savant 10+ year member]

Originally posted by Goddyd4me most of them put out what they are rated at on the alt...mine is a 90amp alt.......so ur running aprox 800 total watts......800w/14.4v = 55.5ampers.....that amp will draw aprox 55 ampers max if it was 100% effecient....i'm goin to say its anywhere from 60-80% effecient....so your looking at 33-44ampers of current max

Um.. as the efficiency drops, doesn't the amplifier draw MORE current? to make up for the lack of efficiency? So if you had ~55 amps at 100 %, you whould have ~110 amps at 50%.. right?

And, no.. a cap wouldn't be what you want.. you would want to get your alternator re-wound or get a bigger alternator if you need one..

The best suggestion is to get the amps set where you need them and see if you have any electrical issues (like lights dimming, etc).. if everything looks ok you should be ok.. there is a good chance that you won't be running the amps at full power anyway.. if you do, you will probably need a new alt (or get your re-wound) as 800 Watts at 50% is ~110 amps...

Hope that helps..

 

[HectorZ 10+ year member]

holy crap this is all new info to me and im scared....

im gonna have 2 JL 300/2's and possibly a JL 500/1

right now my BMW is running a 140 ampers alternator...

do I need to buy a new biscuit factory ????

 

[Savant 10+ year member]

Depends on a lot of things, actaully..

Looking at 1200 watts (300x2, presuming 600, you said 2 of those?) you draw ~170 amps at 'full' power with an amp that is ~50% efficient. If it's up to 60% you draw ~140 amps at 13.8 volts.. add the other amplifier and you go up to ~240 amps at 50%.. Keep in mind, the 'max' for the amp is kind of pointless since you can't sustain that for long and will sound like crap up there.. I do my calcs on RMS since that's the 'real' power I'd be able to use.. if your 300x2 is 150 each channel and 75 RMS, you get ~45 amp draw (150 watts RMS x 2).. if it's 300 RMS per channel with 4 channels total, it's closer to ~170 amps..

This is based off a calcualtor I found ( http://www.eatel.net/~amptech/elecdisc/systemdesignassistant.swf ) but I don't how close to perfect it is.. seems pretty close to me.

The best alt I saw for my truck was 200 amp, and I need ~265 for all 1800 RMS of my bass. .isn't gonna happen for a LONG time... I'm guessing I'll be running only about 300 RMS to match my stock system, if that much.. maybe closer to 200 RMS..

not sure how the extra deep cycle battery helps for long periods.. or if you can run multiple aternators or not (I'd immagine you could but you have a lot of custom fab work to do)..

It all just depens, more efficient amps draw less current for the same power...