Over the last couple of years, more and more digitally controlled amplifiers have entered the market. This concept has been around since the late '80s and early '90s-PPI had the DCX controller and a series of digitally controlled amplifiers while Rockford Fosgate offered the Symmetry controller, among others. With its introduction at the 2004 Consumer Electronic show, Kicker is now offering their SX line of amps with a digital interface that controls all of the usual amplifier functions and then some.
For the most part, the SX400.2 is your standard class AB amp, but with a powerful DSP built in. Kicker packed a ton of features into their digital signal processing by implementing features like gain, equalizer, crossover, security lockout, diagnostics (SickBay(tm)), phase and compression. What's striking about this amplifier is there are no knobs or switches; everything is controlled through the digital interface (ISIS) on top of the unit. Power output is said to be 100 watts x 2 at 4 ohms, 200 watts x 2 into 2 ohms and 400 watts x 1 at 4 ohms bridged-more on that to come.
The main component of the SX400.2's chassis is an extruded, black anodized aluminum base. Built upside down from typical amplifier construction, the heat sink resides below the PCB and rises up to include horizontal heat-sink fins on the front and back sides. A silver sheet-metal shroud covers the top and incorporates a window for the DSP control module that contains a blue VFD display and push buttons. The endplates to the chassis containing the connections are constructed of sheet metal and have been powder-coated black. Blue, cast aluminum EndKaps(tm) that bolt to the top with gothic points stretching almost to the middle of the amplifier cover the connections. This is an incredibly cool-looking amp, especially with the blue letters scrolling across the display.
Power, ground and remote enter through large gold-plated brass terminals on the left side (power and grounds will accept 2awg cable). The speaker outputs also use good-size brass terminal blocks, and get this: all of the terminal blocks and the EndKap(tm) screws use the same 3mm allen wrench! (If you don't understand the significance of this, you haven't installed enough amplifiers that require a different tool for every screw.) The RCA inputs, speaker outputs and remote level control jacks are on the end opposite the power terminals.
Circuit Design
Inside there is a fairly systematic flow to the layout, with power supplies at one end and signal path and speaker outputs at the other. There is a daughter board that contains the RCA inputs and digital signal processing. No doubt Kicker uses this board for all 2-channel digitally controlled models, simply mating it to the larger or smaller amplifier main boards of the various size amplifiers.