The “dedicated to 12 volt” group of folks at Cerwin-Vega Mobile recently dropped off a new toy for me to have a look at. When the name Cerwin-Vega comes up, most of us think huge monster woofers, and multi kilowatt amplifiers, so what they brought me came as a surprise. The amplifier that company president and certified car nut Mike Morris handed me was, in a word, small. Not exactly what I expected from a company that has a reputation for being loud, proud and in your face.
Mr. Morris informed me that this was a new amplifier from their soon to be released Stealth Series of amplifiers, and would be joined in the lineup by a 220 watt, two channel model and a 500 watt monoblock. He went on to explain that while the company’s philosophy hasn’t changed, the expectations and requirements of the average customer have, and the Stealth Series of products are meant to fit the needs of the modern enthusiast by reducing size without compromising the performance. To accomplish this, the Stealth amplifiers utilize the very latest in full range Class D technology. But, before the amps could be released, they had to undergo extensive and time consuming tweaking and listening tests before they were considered good enough to earn the Cerwin-Vega Mobile badge.
The amplifier I got for evaluation is the new four channel Stealth 440.4, and it’s rated at 65 x 4 at 4 ohms, or 110 x 4 at 2 ohms. It has fully independent front and rear crossovers, and bridgeable stereo channels, so it could readily be used to drive a subwoofer system and a pair of components. Bridged power is rated at 220 watts at 4 ohms.
In a departure from their other products, this amplifier does indeed use full range Class D as its topology. Because of the high power efficiency of the Class D design, the amplifier can have a much smaller heatsink for a given amount of power. And this amp is indeed small, measuring 10.5” long (including terminals) by 7” wide and only 1.75” tall. On one end of the amplifier you’ll find the power and speaker connections. These are fully insulated set screw type designs, with 3.0 and 2.5mm hex head set screws. The power connectors will accommodate 4 gauge cables, and you can run up to 8 gauge speaker cables. A pair of 20A ATC style fuses plug into chassis mounted sockets. The other end of the amplifier is all about signal connection and control. The RCA connectors are rugged looking nickel plated panel mounts, and they’re color coded for quick Left/Right identification. Gain is adjusted using a single pot for each pair of channels. The crossover section is identical for front and rear channels, and includes separate pots for high pass and low pass, each with an adjustment range from 50 to 250Hz. Bass equalization is included for all four channels, with the “Vega Bass” control adjustable from 0 to +12dB of boost at 45Hz. A small blue power LED rounds out the features on this end of the amp. When he brought the amplifier to me, Mr. Morris mentioned that part of the “tweaking” process was ensuring that the gain pots tracked evenly left to right at all positions, and that the crossover filters were indeed true 12dB Butterworth alignments.
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