Actio = Reactio

Isaac Newton 1726

Physical basics

According to Newton's 3rd law, each force also generates a counterforce in the opposite direction. An indispensable physical effect for rocket technology. With loudspeakers, however, this counterforce is a problem and undesirable, since the reaction force must be derived from the cabinet and the coupled environment. The vibrations of the cabinet are excited and mixed with the original signal of the sound generator. They become audible as disturbing and distorting components in the wanted signal.

If the generated motion impulses are considered, they cancel each other out. Hence the name impulse compensation.

Application

Pulse compensation is successfully applied to woofers with a frequency range below 150 Hz. Two mechanically directly connected bass loudspeakers are mounted on the opposite sides of the loudspeaker cabinet. They radiate in the same plane and no unwanted runtime effects occur. Since these mirror-image loudspeakers oscillate in the opposite direction, the reaction forces act in the opposite direction and compensate each other.

Without these reaction forces, significantly fewer undesirable oscillation states or resonances are excited at the housing, so that the disturbing sound components in the useful signal decrease. As a result, the housing is a magnitude (factor 10 and greater) quieter in the room. Not to forget is the faster transient response to changes in signal strength in the low-frequency range. The dynamics of the reproduction increase.

No unwanted runtime effects
Significantly less resonances
Decrease of disturbing sound rates
Faster transient response