deafwish wrote:
I'm sure you are aware that an amp' will VERY rarely supply anywhere near it's full capacity of wattage, while playing music?!
Get your hands on a clamp meter and test the current draw when your sound system is up loud.
You will be very surprised at how little it will draw.
p.s. The amount of speakers has nothing to do with current draw. Impedance has everything to do with current draw. Google it.
1400 watts is 1400 watts no matter how you look at it. Being class D it's near 90% efficient in turning that 14.5v into speaker noise, but power doesn't come out of thin air. In fact, class D amps only become 90% efficient at near max levels. At low volumes at like let's say something you can talk over... 500w output, it might only be 50% efficient, so you're still using 1000w of power. At ear bleeding volumes it might be using 1600w. At whisper levels (200w output) it's even worse, so you might be drawing a total of 500w. So times that by two you're still over 1000w, or 50a draw. Lower the voltage to 12v when the engine isn't running it's even worse. That number might go up to 55-60a draw for two 1400w amps at quiet levels. Or under 30 minutes of radio.
I'm sure it will sound awesome for a few minutes. Awesome project but it doesn't have the power supply to run it. This wouldn't even work in a car without a massive alternator upgrade. In the car world it's easy... just buy a higher rated one like 200a... but I have yet to find a marine rated 200-250a Alternator.