Equipment Required
•AC voltmeter
•Signal Generator capable of outputting a sine wave up to 2V RMS
•Flat bladed screwdriver to adjust the rotary controls of the CT8 XO
And to adjust the equalisers to optimise the
•Laptop PC with WinMLS 2004 (or later version) software installed
•External sound card
•Measuring microphone
WinMLS may be purchased directly from the software supplier, in which case it should be WinMLS 2004 or later and be to level 3 license. It should also include the specially created “B&W CT800” measurement module. Early versions of the software did not include this module, but the latest version may be downloaded from www.winmls.com.
However, a special package that includes a suitable microphone, USB sound card and a cut- down version of the software that includes everything required for tuning a CT800 system may be obtained directly from B&W. Contact your country distributor for details.
Ths illustrations on the following pages refer to the B&W version of the software. The standard version will differ slightly.
Configure the CT800 XO to the speaker
Set Bank 1 Switches 2 & 3 to the type of speaker.
Set Bank 4 Switches 1, 3 & 4 according to the number of subwoofers attached. The conditions of Switches 3 & 4 are irrelevant if Switch 1 is set to ON.
Configure the unit to the gain of each power amplifier
The reference gain is that of the power amplifier feeding the MF/HF drive units. If using the same type or even the same gain of power amplifier throughout, simply set Bank 2 Switch 1 and Bank 4 Switch 2 both to ON.
If the power amplifier gains are different, you will need a sine wave oscillator and AC voltage meter to set the correct compensation gain in the unit.
During this process, the parametric equalisers should be bypassed by setting DIP switches 2 and 3 in bank 2 to OFF and the contour controls (C1 & C2) set to zero.
Setting the LF gain
Disconnect the speakers from the power amplifiers.
Connect the MF/HF power amplifier to the LF output of the unit.
Set the output level of the oscillator to zero and connect it to the appropriate test input socket.
Set the oscillator frequency to 100Hz.
Set Bank 1 Switch 1 to ON.
Set Bank 2 Switch 1 to ON.
Set Bank 2 Switches 2 & 3 to OFF.
Connect the AC voltmeter to the output terminals of the MF/HF amplifier.
Raise the output level of the oscillator until the meter reads 2 volts.
Substitute the LF power amplifier for the MF/HF power amplifier. Do not alter the output setting of the oscillator.
Set Bank 2 Switch 1 to OFF.
Adjust the LF output gain control (C13) until the meter again reads 2 volts.
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