Class X amps

The Class X amp is a new class of amplifiers that many of the manufacturer's are coming out with now. This is a claim from one of the companies:

" Class X Mono Amplifiers exclusively for subwoofer use, are as much as 3 times more efficient than Class AB amplifiers. With efficiency ratings near 90%, they make the most of the power you give them to produce the most bass possible. This means that 90% of the power supplied to a Class X amp will be converted to MUSIC, not heat. As compared to a Class AB amp, which may convert as low as 30% to music, and 70% to HEAT! "

Hey Big Purds, I think your right about the Class X and the fact that it's a gimmick for the lower end or beginner companies to ride the Class D wagon in their own little niche. The companies that I have researched for these " Class X " amplifiers are mostly the high volume, low end companies ( not saying that they are not good, but not as good a reputation as some of the more main stream companies ).

Companies with Class X amplifier: Visonik, Farenheit, MA Audio , Autotek

From What I know there is Class E thru H, and Class-T (Tri-Path). Nverhad I heard about Class X, Sounds like a Model line mname or Marketing VoDoo or Snake Oil.

Class E operation involves amplifiers designed for rectangular input pulses, not sinusoidal audio waveforms. The output load is a tuned circuit, with the output voltage resembling a damped single pulse.

Class F are similar t Class E  yet use more complex output tuned, output. circuits. Class C,E, and F are more commonly used in Communications applications.

Class G operation involves changing the power supply voltage from a lower level to a higher level when larger output swings are required. There have been several ways to do this. The simplest involves a single class AB output stage that is connected to two power supply rails by a diode, or a transistor switch. The design is such that for most musical program material, the output stage is connected to the lower supply voltage, and automatically switches to the higher rails for large signal peaks [ thus the nickname rail-switcher]. Another approach uses two class AB output stages, each connected to a different power supply voltage, with the magnitude of the input signal determining the signal path. Using two power supplies improves efficiency enough to allow significantly more power for a given size and weight. Class G is becoming common for pro audio designs. [Historical note: Hitachi is credited with pioneering class G designs with their 1977 Dynaharmony HMA 8300 power amplifier.]

Class H operation takes the class G design one step further and actually modulates the higher power supply voltage by the input signal. This allows the power supply to track the audio input and provide just enough voltage for optimum operation of the output devices [thus the nickname rail-tracker]. The efficiency of class H is comparable to class G designs. [Historical note: Soundcraftsmen is credited with pioneering class H designs with their 1977 Vari-proportional MA5002 power a mplifier.]