Large white servo subwoofer from the famous, but now defunct, a/d/s company.
"It is servo controlled, which means that there is an accelerometer
attached to the cone of the woofer measuring its actual movement and
comparing it with the original input signal and making necessary
corrections. The result is ultra low distortion. Further, this sub is
rated to play down to 17 Hz! below the threshold of human hearing, where
most subwoofers fall short."
Features and Specs (taken from another site):
- Driver: Long excursion 300mm/12" Stifflite cone driver w/ 2" edge wound single layer voice coil
- Magnetically shielded
- Electronic servo control
Cabinet: Computer optimized and equalized 4th order bandpass design
with LamflowTM dual port technology - laminar flow reduces "chuffing",
or port turbulence: the unwanted sound of air moving in and out of the
- Amplifier power: 250 Watts RMS/continuous, 20 Hz -100 Hz
- Frequency response: 17-100 Hz
- Maximum output: 110 dB!
- Crossover slopes: 24 dB/octave, 4th order Linkwitz-Riley characteristic
- High pass crossover: 60 Hz, 80 Hz, or 100 Hz
- Low pass crossover: 45 - 170 Hz, continuously variable
- Subwoofer level: off to +6dB, continuously variable
- Satellite output: Low level input - unity gain
- High level input -20dB
- System distortion: <1% THD!
- Input sensitivity: Low level input - 150mV
- High level input - 1.5V
- Input impedance: Low level input ->=20K Ohms
- High level input - 2.2K Ohms
- Output impedance: <=150 Ohms
- Line voltage: 115VAC, 60Hz
- Line current: 400 Watts, maximum
- Dimensions: 20" H x 20" W x 20" D