WM8 "BASSIS" Bass Correction Equalizer
Adaptable to all acoustic-suspension speakers.
Adjustable bass boost and damping.
20 Hz subsonic filter.
The BASSIS is a specialized parametric equalizer
with two purposes: (1)
to correct the irregular bass response of many acoustic-suspension
loudspeakers; (2) to extend the bass response as much as two octaves
The damping (Q) of the new bass cutoff can be adjusted according to the
listening room acoustics and the user's tastes. In consequence, any
can be corrected to obtain deep yet well controlled bass, providing
with a greater sense of impact and "openness".
of the bass response of a typical "boomy" speaker,
with bass falling off below 60 Hz. By adjusting the BASSIS, its own
response (curve B) may be made the inverse of the speakers curve, down
15 Hz. The combination of the equalizer and speaker is shown in curve
C, with a smooth response and a -3dB point at 15 Hz. Note that it is
generally not possible to perform this sort of correction with
a conventional graphic equalizer, due to the spacing of the frequency
bands of the sliders.
The BASSIS can also reduce the "boominess" of poorly-tuned vented loudspeakers; or the vent can be plugged for use with the full range of equalizer options.
The BASSIS employs a 4 amplifier bi-quadratic filter, with additional op-amps to allow independent adjustment of the various parameters, and to ensure system compatibility. The circuit contains high-speed op-amps,film capacitors and metal film resistors. Four rotary controls are provided for each channel, to match the cutoff frequency and damping of any acoustic-suspension speaker and to set the bass boost and net damping. A 20Hz high-pass filter (subsonic filter) can be switched in from the front panel to eliminate unwanted subsonics.
SPECIFICATIONS Frequency response: 2Hz to 100 KHz, + 0.2 dB/ -3 dB Harmonic distortion: less than 0.01% (at 1 KHz) Signal to noise ratio: better than 110dB Input impedance: 100K Output load capability: 100 Ohm min Output impedance: 10 Ohm typ Maximum input voltage: 25 V peak-peak (8.8 V RMS) Maximum output voltage: 25 V peak-peak (8.8 V RMS) Power supply requirement:120 VAC, 60Hz, 10W Dimensions: 17"W X 10"D X 3.5"H Construction: All metal cabinet, black with white legend FRONT PANEL CONTROLS and READOUTS Bass boost range: 0-24 dB Net Q range: .25 to 1.0 Speaker resonance range: 30 Hz to 130 Hz Speaker Q range: -4dB to +6 dB at Xover frequ. 20 Hz Cut: on/off Bypass: on/off Power switch: on/off REAR PANEL CONNECTORS Input, output: RCA phono (2 each) Line power fower fuse: 1 Amp Power: IEC connector for linecord ORDERING INFORMATION WM8-KK Kit with manual and all parts WM8-C Custom cabinet only WM8-AA Fully assembled and tested WM8-B Single channel bare board with manual WM8-K Single channel board kit (parts & manual) WM8-A Single channel board assembledFor free manuals download go here.