Detailed Information

The conventional way to get high power in a car amplifier is to use a switching power supply. This increases the battery voltage from its nominal 12V to something higher–the more powerful the amplifier, the greater the required voltage. This power conversion is never perfectly efficient–about 10% of what goes into the amplifier is wasted and ends up dissipating into heat.

JL Audio's Direct Conversion Class-D Technology (DCD™) innovates by eliminating the need for this power conversion step entirely. Because we are still bound by the laws of physics, the lack of a step-up power supply means we have to extract as much power as possible from the vehicle's 12V supply. If we were to connect a DCD™ amplifier to a conventional 4-ohm subwoofer with this limitation in place, we would only achieve about 25 watts, and we all know that powering a subwoofer requires a lot more power than this.

To overcome this obstacle, the DCD™ amplifiers have been designed to drive extremely low impedance speaker loads–as low as 1/4-ohm (0.25 ohm)! With these very low impedance loads, we can deliver up to 500 watts of clean power, subwoofer power. Those who know Ohm's law and that nothing is free realize that this will require a lot of current to flow, and that's exactly what DCD™ is engineered to deliver...over 50 Amps peak into a speaker!

To deal with these high current amounts, the special, very low-impedance JL Audio Subwoofers used with DCD™ amplifiers are engineered with unique voice coils and tinsel leads. Connections between the amplifier and speaker are made using special heavy gauge speaker cable, with special attention paid to connection integrity to deal with the high current output.

The benefit of all this effort is that DCD™ amplifiers completely avoid the losses associated with a switching power supply, allowing the entire amplifier to achieve total power efficiencies in the 91-94% range. This is very close to the theoretical limit for Class-D efficiency and results in very little heat being generated. All of this allows for a very compact, powerful amplifier that can fit in some of our most space-efficient enclosed systems.