Amplifier selection question?

[rosphill]

I have installed newer aftermarket speakers and headunit and want the system a little louder with these new speakers. I've read that the alternator in the 3rd gen T4R is kinda weak sauce etc. What size amp becomes a problem for power draw from the battery? The rear speakers are 180W and the fronts are 200W so could I just get a 4 channel 200 W amp, move the bias to the front and tone it down some across all channels?
I am somewhat of a novice at the car audio stuff, so would appreciate input to keep me from blowing anything up!
I'm not wanting to spend very much or win any contests, just a little boost in decibels.
Thx much!

 

[004Gunner]

I assume that power rating is peak and you really should go by the RMS instead. Either way you should not have any issues with what you want to do. I run 2 fronts off my front channels and bridge 1 10" to the rears of my 4 channel and have never had any issues at all. It can handle it.

 

[Clemsonfan15]

You have to look at RMS not peak. Peak or Max ratings are garbage.

I am running a little over 1,000 watts, about 1,100 on my stock electrical system. I have a '98 Limited and I see no diming at all (knock on wood).

 

[Stevec717]

Some simple automotive electronic math - If your amplifiers are drawing a true 1200 watts And remember, input will be higher than output due to efficiency losses, i.e. a 1000w output amp might use 1200w input power. And you need to look at average (not peak power). So maybe a big system draws 600W continuous. 600W @ 12volts = 50 amps. 50 AMPS :awais:

That's a lot of current! That needs 10 ga or heavier wire just to carry it. And while that's well within the capacity of even a stock alternator (most are 80-120 amp) by the time you add headlamps and the rest of the electical system, you could be starting to get close to capacity.

A good trst might be to see if with engine at 2000 RPM (cruise) headlamps on and stereo ripped, does battery voltage drop below 14V? Is so, alternator might not be keeping up with load.

 

[Clemsonfan15]

Some simple automotive electronic math - If your amplifiers are drawing a true 1200 watts And remember, input will be higher than output due to efficiency losses, i.e. a 1000w output amp might use 1200w input power. And you need to look at average (not peak power). So maybe a big system draws 600W continuous. 600W @ 12volts = 50 amps. 50 AMPS :awais:

That's a lot of current! That needs 10 ga or heavier wire just to carry it. And while that's well within the capacity of even a stock alternator (most are 80-120 amp) by the time you add headlamps and the rest of the electical system, you could be starting to get close to capacity.

A good trst might be to see if with engine at 2000 RPM (cruise) headlamps on and stereo ripped, does battery voltage drop below 14V? Is so, alternator might not be keeping up with load.

Most of the above is true, but I would like to clear a few things up.

I am running 1,100 watts without any diming (this is with lights and A/C on). This is not the rms of the amp, this is what I am auctually pulling. The amp is rated at 1400 RMS, so with efficiency and such it drops to about 1,100.

When you go to buy your power cable and ground cable get 0 gauge. You should also do the Big 3. It's very simple, but can make a big difference.