As in all PSB SubSeries models, this subwoofer utilizes a high efficiency high power Class H power amp. Class H is a special high efficiency amplifier design. Briefly, audio amplifiers are inherently inefficient because they are designed to have the capability of delivering great output power yet spend most of their life delivering fairly low power. Their output devices must deliver current while  withstanding the high power supply “rail” voltages needed for peak outputs. With a Class H design the rail voltages are not constant. They swing high when the music demands it and stay low during quiet passages. This is achieved by a sophisticated high frequency switching power supply. Power dissipated as heat is greatly reduced and more power is available. A second benefi t is that they tend to have high peak power relative to their steady state power.

The SubSeries 500, for example, has 500 watts continuous power and is capable of over 1500 watt peaks. The result is a subwoofer capable of the great transients required by dynamic music and explosive sound effects. The SubSeries 500 offers the latest most effi cient implementation of this special Class H technology.

There are a few other parameters that we feel are very important in the design of a subwoofer. The most important of these is that a PSB subwoofer be musical. In an era of home theatre this might at first seem out of step, but we believe that a musical subwoofer will also sound the most natural when playing movie soundtracks. An ideal subwoofer should have the ability to play musically even under conditions of overload or stress. Whatever the size no subwoofer is immune from being overloaded, especially with modern movie soundtracks. For this reason PSB subwoofers incorporate very intelligently applied proprietary limiting circuitry to prevent audible overload.

The SubSeries 500 is constructed from thick MDF and aluminum extrusions forming an extremely rigid cabinet free of any audible resonances due to panel or brace movement. Large elliptical ports with large radius flanges drastically reduce port noise to inaudible levels while minimizing acoustic compression common to smaller diameter port designs. Air will create noise whenever it comes into contact with a hard surface. Minimizing the area of the surface that the air actually comes in contact with reduces this noise. A severe duty aluminum cast basket, very large magnet structure and high powered voice coil allow the SubSeries 500 to effortlessly churn out low frequencies at foundation shaking levels.