Servo controlled speakers and subwoofers

What they call "servo" control is actually an accelerometer on the woofer's cone that reports back the movement of the cone. The servo box compares the report from the accelerometer to the actual signal and corrects the differences.

Problem is with long control cable is the woofers tend to be slow in relation to the music. The Infinity IRS Beta suffered from this especially. Newer and faster designs are out there in most of the newer servo subs/woofer/speakers.

The "servo control" is in addition to an amplifier. A "regular" amplifier is still powering the woofer.

Best,

Paul :-)

A servo involves a sensor on the controlled device (in our case a small accelerometer on the woofer cone) which measures movement of the cone. With a non-servo system the power amp puts out a voltage according to the input signal. The voltage is applied to the driver, but how the cone moves depends on the driver characteristics, and no driver is perfect. With a servo system, if the driver fails to move exactly in accordance with the input signal the error is measured, and the power amp output is modified to correct it.

Beemer is exactly correct, and thus unfortunatley has to reveal he's over 60? if he remembers the IRD Beta problems. I even remember the Infinity Servo-Static! which had similar problems, but was a 'killer' product in its time!

Today, the long control cord problem has been solved by simply including a dedicated SS amp within the sub. Personally, I wouldn't buy a sub without a servo (accelerometer) it solves so many problems, though not a substitute for cheap construction/drivers.