Servo controlled speakers and subwoofers

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.

Mitch, actually, I don't use those SW-800s (Kinergetics) anymore. I use a single Martin Logan Depth and it's great (it does use a servo, BTW) Sorry about the outdated pic. That's one of my spring projects.

Most on-board sub amps are I believe Class D "switching" amps. They're designed to only drive the lowest couple of octaves. I'm not clear on why, but they don't require big power supply transformers or storage capacitors.

You still need a "regular" Class A or A-B amp for the mid/highs, although there are now some alternates to those as well.

Happy b'day Speedy!