alternator question???

[jamie vandenh 10+ year member]

I am looking at getting an 18" Fi BTL

the sub is rated at 2000 watts rms, so I am going to need an alternator...

What specifics will i need for an alternator to power this on about 2000-2500 watts?

also, will a regular car battery suffice for this?

This is the first time i have been using a setup with over 1000 watts, so i am fairly new to using extra batteries/alternators

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[Chris Z 10+ year member]

If you wanna keep this guy running at 2000 w rms @ 14.4V - it'll draw ~140 amps, at 12.6V it will draw ~ 160. If you want 2500 w rms @ 14.4V it'll draw ~ 175, and at 12.6V it'll draw ~ 200 amps.

 

[n2audio 5,000+ posts]

If you wanna keep this guy running at 2000 w rms @ 14.4V - it'll draw ~140 amps, at 12.6V it will draw ~ 160. If you want 2500 w rms @ 14.4V it'll draw ~ 175, and at 12.6V it'll draw ~ 200 amps.

Valid if 1) the amp is 100% efficient, and 2) you're playing constant full volume sine waves.

Realistically -- a fairly efficient (80%) class D amp will draw around 180A at peak RMS output. Thankfully that much current will only be require for short term bursts, and only occur when you're listening at full volume. Your AVERAGE current draw for an amp like that is going to be in the 60A range at full volume. 30-40A if you're not blasting it.

I would be looking for a 150A alt at the minimum (if you don't anticipate blasting it all the time). If you want to play it loud a lot -- 200A.

I run 1500 rms (1000w sub/500w comps) with a 110A alt and it runs pretty smoothly.