Amp Efficiency and wiring

[n2audio 5,000+ posts]

on 1300 watt rms d class amp average amp draw is going to be more like 65 - 70 amps. and yes, he way overstated when he said you can run a 4000 watt amp on most stock alts. it might run for a while but when the voltage drops below 9.5 volts for long period of time "poof goes the amp" and may take out some subs at the same time. if you run a d class amp at very low voltage it will clip. i would rather overbuild the electrical than take a chance. too much won't hurt a bit(in fact you get alot more out of the system) but, not enough will cost you more in the long run.

Sorry pawn, just not buying much of what you have to say.

65-70A RMS at 1300w??

I just don't think you understand how much current 60 "continuous, long term" amps is. For 1300w to reqire that much current it would have to play at full volume, bass heavy, and heavily clipped ALL the time. Very few stock charging systems that I know of could BEGIN to stand up to that, and I know of a LOT of people running 1200-1500w on stock alts and single batteries. RC meant it when he said it is a RARE system that requires 50 continuous long term amps.

If a car's voltage drops to 9.5 there would be a lot more problems than the sound system. A battery is considered dead at 10v. At 9.5 I would expect the ignition system would be unable to generate enough spark for the engine to run. Besides, most good amps will have low voltage protection at 10v or so.

And blowing subs due to low voltage?? So you're saying less power means dead speakers? Is that logical?

Why would an amp clip simply because of low voltage? If voltage sags and the amp is unregulated output will sag accordingly. Unless the user responds by cranking up the gain clipping isn't part of the equation.

In regulated amps the power supply will respond to low supply voltage by increasing the pulse widths and actually run more efficiently up to the point that the voltage gets TOO low, the PS can't keep up and protection kicks in.

Clipped or unclipped - if power declines so do the odds of damaging a speaker.