Crown IQSMX-6 Computerized Control and Monitoring, Automatic Mixing Features, Crown Bus Connector

AMB-5 /SMX-6IQ Mixer/Multiplexer

output channel) via RCA pin jacks. Each input en- ters the mix of the respective output channel at unity gain, and without manual or computer input control. These stack inputs allow you to multiply the number of audio inputs by stacking 2, 3, or more units to build a larger mixer. See section 5.1.4 for more infor- mation about forming larger mixers.

4.1.10 Crown Bus Connector

A4-pin removable barrier block connector is pro- vided for digital communication via the Crown Bus serial data loop to other IQ components. A ground lug is provided to connect an optional shield for the Crown Bus input.

4.1.11 Crown Bus Ground Connector

This chassis ground stud is provided to connect an optional shield for the Crown Bus cable. Only the shield of the input cable should be connected. Shielded wire will reduce the total distance a Crown Bus loop can be run, but shielding may be neces- sary to reduce interference with certain kinds of audio cables. See section 5.5 for more information about wiring the Crown Bus.

4.1.12 RS232 Serial Computer Port

A9-pin DB9 serial computer port is provided for direct communication with a computer. The mixer/ multiplexer is capable of serving as a system inter- face for up to 20 IQ mixer/multiplexers.

4.1.13 Sensing AUX Port

ATB-3M type “mini-XLR” connector is provided for AUX input and output. This port may be used to provide a control signal or sense a control signal. Pin 1 is ground reference. Pin 2 is a sensing input. A signal between +5 to +30 VDC is sensed as a logic high. Because the circuit floats, the input line must be tied to ground or a control voltage source to be used. Pin 3 is output under processor control. When on, it provides 10 VDC at 16 ma, and when off, it is effectively an open circuit (high impedance). Sec- tion 6.2 describes example applications for the AUX port.

4.2 Computerized Control and Monitoring

The following features are controlled and monitored via IQ software.

4.2.1 Manual/Auto Mode

This feature switches the mixer/multiplexer between Manual and Automatic modes. When in Manual mode, you may make changes from software that

affect VCA gain in real time. Gain may also be ma- nipulated in real time from alternate third-party con- trol systems or devices. In manual mode, once VCA gains are set via the PC (or control device) the processor maintains those settings until it receives an instruction to change.

4.2.2 Input Level Monitors

Audio level monitors are provided for each input. The level is sensed between the preamp and VCA's, with a range of –40 to +25 dBu.

4.2.3 Output Level Monitors

Audio level monitors are provided for each output. The level is sensed at each output mix bus with a range of –40 to +25 dBu.

4.2.4 Bus Output Relays

Audio bus outputs can be switched on and off with software controlled isolation relays.

4.2.5 VCA Gain Controls

Each input may be routed to either or both outputs by VCAs under processor control. The processor may, in turn, be set up to control VCAs using on board automatic intelligence or may be controlled in real time manually from software. The VCAs offer a control range of –100 to +25 dB.

Automatic Mixing Features

The following features make up the Automatic Mix- ing Feature Set, and are only functional when the mixer/multiplexer is in Auto mode. All features are common to the IQ–AMB-5 and IQ–SMX-6 unless otherwise stated.

4.2.6 Gate

The gate feature shuts off or attenuates inputs when not in use. This feature is particularly useful to pre- vent feedback caused by too many open micro- phone channels. There are four parameters which control this feature:

•Max Gain control: used to set the maximum gain for an input to one of the two outputs when Auto is turned on. The Max Gain setting has different effects when different Auto functions are active. For example, when the Gate func- tion is activated the Max Gain will be the “gate open” level. When then Input Compressor/Lim- iter function is activated, it acts as the “limit,” the upper gain achieved when no compression is taking place.* Control range is from –100 to

Page 16 IQ–AMB-5 / IQ–SMX-6 Reference Manual