Originally Posted by
EarmarkMarine
I'm an advocate of Class D amplifiers. Kicker has fullrange Class D, so does Alpine and so does JL Audio. You can drive a single pair of KM6500.2 for as little as $250 with Class D power. Here are a few of the advantages.
A Class D amplifier is 60 percent more efficient than a Class AB amplifier. To put that into a little perspective consider this.
A Class AB amplifier will typically generate 250 percent more heat from the same supply current as compared to a Class D. And, a Class AB will typically generate 400 percent more heat relating to the identical output power as compared to a Class D.
A Class D amplifier will produce 60 percent more output power than a Class AB amplifier with the same available current.
A Class D amplifier will deliver 60 percent more play time at rest over a Class AB amplifier at the same output power with the same battery reserves. Or, the Class D amplifier will not cycle the batteries as deeply as a Class AB amplifier at the same output over the same duration. Shallower cycles promote extended battery longevity, even for deep cycle batteries.
Class AB amplifiers directly increase the current draw on the alternator and additionally increase the alternator draw due to the greater depletion of the batteries. A greater current draw on the alternator results in more internal alternator resistance which commands more horsepower. Alternators also run hotter with a full system of Class AB amplifiers than a full system of Class D amplifiers.
Class AB amplifiers consume substantially more current resulting in an increased voltage sag. Unregulated amplifiers drop in output power as the voltage decreases. For example, an unregulated amplifier that is rated at 14.4volts may drop 25 percent of its power as the voltage supply drops to 12.5 volts and the power loss increases as the voltage continues to fall.
Makes the small increase in admission cost of Class D seem minor for all the energy efficiency and performance advantages. Lower battery costs. Less fuel consumption. No need for alternator upgrades even on large systems. MUCH less waste do to heat generation. Higher power levels under adverse conditions. Better audio performance with less voltage sag. Longer play time at rest. Friendlier to the boat electronics.
David
Earmark Marine