DIRECTOR - the Modular Surround Controller System

Volume and Matrix Control Unit Top PlateInput Selector, PFL and DIM Control - Top PlateDown Mix Matrix

The down mix matrix is inserted between the optional cut solo circuit and the optional filter. A 4-channel (quad surround), a stereo or mono down mix can all be procued from 6 input channels

Each format is produced from the format withe the next highest channel count (mono from stereo, stereo from 4-channel, etc.). Four switches (DECODER, SRD, STEREO and MONO) are used to determine the desired format, with 5.1 being the default of the Director surround controller system.

The Surround Matrix

A 4-channel (LCRS) signal is produced by the 5.1 surround matrix. The LFE channel is processed with a low-pass filter and is mixed to the 3 front channels. The frequency of the low-pass filter (normally 80 Hz) and the attenuation (normally -6 dB) are adjustable by trim-pots. A matrix adds both surround channels LS and RS to a mono surround signal. If SRD is selected, the LFE is switched off. The mono surround channel S is fed to both surround outputs in parallel. The surround matrix serves, first of all, for the control of the signal changes caused by the encoder/decoder system.

SBlock Diagram Control Room PFL Section and Filters in Surround Controllertereo Downmix

The stereo matrix treats the LFE in the same way as the surround matrix. The surround channels LS and RS are added to the L and R channels respectively. In addition, the center channel with the same level is added to the L and R channels. The level relations of these interventions are determined by the positions of two stepper switches. The attenuations 0 dB, - 3 dB, -4.5 dB and -6 dB are selectable for the addition of the center channel to left and right. 0 dB, -3 dB, -6 dB and off can be selected for the addition of the surround channels to the respective front channels.


The mono matrix adds both outputs of the stereo downmix matrix to form a mono signal. This matrix can operate with - 3 dB or - 6 dB attenuation and defaults to - 6 dB. The configuration is made by a jumper on the pcb.


The PFL signal is inserted after the output of the matrix. The PFL audio input is switched to the control room section and/or the meters respectively by the switches PFL SPK and PFL METER. Remote control inputs are available for both functions. The stereo input for PFL is balanced and operates on nominal level. The control input is separated by an opto coupler. Voltages from 5 Volts to 30 Volts can be used. When PFL is selected either by the local switches or by the remote control, the input signal with its original level is switched to the mters while the level of the speakers is controlled by a rotary pot. A coding switch determines the disrtribution of the PFL input to the output channels. Each channel can be configured to monitor either the left or right PFL channel. All channels that are not assigned to PFL are automatically muted. The LFE output cannot be selected as PFL monitor. Activation of PFL from the remote port is indicated by the light in the respective PFL switch in the remote unit.

When the DIM switch is activated, the levels of all the loudspeaker outputs in the system are attenuated. The DIM level pot with a range from 0 dB to 30 dB determines the attenuation value. The regulation law is linear in dB. Like PFL, DIM can also be controlled by a remote input with a voltage between 5 Volts and 30 Volts just as described above for the PFL function.

The optional Filter

An optional filter can be inserted after the PFL switching. This filter can be used to insert equalizing into the speaker output channels. We offer a version is an X curve characteristic and another version with an inversed X curve characteristik. With this filter, the monitoring system can be switched between film sound operation and linear operation. The switch FILT inserts the filter into all 6 channels of the aufio chain. The filter itself is a plug in board that is installed in the main frame. Custom characteristics of the filter can be provided, pleas ask.

input circuit of the monitor rail can either be electronically balanced or balanced and floating. A meter tap is located at the output of the input selector. There 8 meter outputs for the channels L, C, R, LS, RS, LFE, LT, and RT. A coding switch allows the configuration of the meters L, R, LFE, LT and RT for automated switching to the PFL signal. There are no standard metering systems supplied with the Director surround controller. However, and adt-audio 5MT meter bridge with an 8-channel meter block type S-LED can be installed with an adapter cable. Of course, any other meter can be installed as well.