how much voltage drop is too much?

[ARSkemp 10+ year member]

Right now i have a 12" infinity perfect vq hooked up to an audiobahn amp (dont remember the model, its an a/b amp set to 400rms with a multimeter). With the amp off the car idles @ ~14.05-14.07V. When playing a 60hz test tone @ 400rms, the voltage drops to ~ 13.75 at idle, so about .3 Volts. I am planning on upgrading to a different system where i will be running ~2000rms on a class d amp. I will be amping the fronts as well but that will still be a long ways away.

Short Story:

400rms A/b amp drops voltage from 14 to 13.7

Planning on upgrading to 2000rms class D amp (supposed to be a little more efficient)

will big three be enough?(havent done it yet)

or should i get a new battery/add a battery/replace alt?

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[Astyl 10+ year member]

if your dropping into the 10.9 range then u might have some issues

 

[Qbenjamin 10+ year member]

I would not run more than 1500w's without a HO alt. A few people on here run 2500w's off of a big three upgrade and second battery. I had trouble running 1K with the same setup as those guys. Headlights were flashing with the music......

 

[dB-SPL 10+ year member]

Your idle voltage without the amp seems a tad low to begin with..

-Bill-

 

[TC2k15x2 10+ year member]

I would not run more than 1500w's without a HO alt. A few people on here run 2500w's off of a big three upgrade and second battery. I had trouble running 1K with the same setup as those guys. Headlights were flashing with the music......

Would it be safe to run a 2500 watt amp off of a stock 150 amp alt? I will be adding a second battery and the big 3 will be done.

 

[morgans432 10+ year member]

Would it be safe to run a 2500 watt amp off of a stock 150 amp alt? I will be adding a second battery and the big 3 will be done.

I do it right now with what you just said but my stock eletrical is awsome.

 

[ARSkemp 10+ year member]

So what voltage would be too low on idle when playing a test tone? I know theirs probably a lot of variables. The only time i will probably ever play test tones is when setting it up and almost all the time when im playing music im not idling (i even turn down the sub i got now @ stop lights if theirs a car next to/behind me).

 

[TreyE 10+ year member]

When You Diieee:evil:

 

[n2audio 5,000+ posts]

So what voltage would be too low on idle when playing a test tone?

Knowing a healthy battery should give you 12.5 or so I wouldn't want to see much below that at idle. Then again, test tones are their own thing, no music requires even 1/2 as much current. If you DO see ~12v at idle try the same measurement with music and see how much higher it is. If it's 12.5v or better I'd say you're golden.