AWS 924-948 - Solid State Logic

Analogue OperationsMonitor Level CalibrationThe monitor calibration system enables the level of any loudspeaker connected to the AWS to be trimmed by ±10dB. Notethat with the monitor gain at maximum a trim level of +10dB corresponds to unity gain through the monitor section.Do not attempt to carry out loudspeaker calibration unless you have accurately calibrated test equipment.Locate the console oscillator (above the TFT screen), press OSC ON and select the PINK ONbutton; the default level for the console’s pink noise output is +4dBu RMS. This calibrated level canbe adjusted using the ‘Pink’ trim pot below the Level control.Set the monitor level control to the position you wish to correspond to the calibrated level. A levelof 8.5 will provide 10dB of additional gain in hand.Now select the monitors to be calibrated using the LS SELECT buttons in the monitor panel.Select CAL in the first layer of MONITOR OPTIONS. Pressing either AL,AR or AC will send pink noise to the Left, Right or Centre loudspeakerrespectively.Adjust the level for the required SPL (eg. 85dBa C weighting, slow response, ona suitably calibrated dB meter), by turning the main monitor pot left or rightfrom its initial position.Now work through the rest of the speakers (see below), checking before you calibrate the LFE output whether the LFOoption (see previous page) is off or on.85dB calibrated level – please see following page.Selecting NEXT produces a second layer of calibration options:Selecting ALS, ARS or ALF allows you to trim the Left Surround, RightSurround or LFE channels respectively by ±10dB, using the method describedabove.LFG (Low Frequency Gain) allows the gain of the contribution from the fullbandwidth channels to the subwoofer output to be adjusted. Like all the speakercalibration settings it must be set for each set of speaker outputs (assumingbass management is in use):Having lined up the six main speakers, select LFG. All speakers will initially be muted, and the six monitor cut buttons willlight. Un-cut the left output and with the bass management turned on (note that the BMN selection in the BASS menuis duplicated in the CAL menu) adjust the LFG gain for a flat low end response. Cut the left output, un-cut the right outputand check this has a flat low end response. Repeat for all channels. Depending on how well matched the monitors are youmay have to adjust the LFG gain slightly.Note that when LFG is on, the LFE monitor output is always cut. This does not mute the actual subwoofer output, onlythe LFE signals feeding it. This ensures that you are only measuring the contribution from the bass management system.AWS 924-948 Owner’s Manual Page 3-19