QSC Audio SC28 Audio Inputs, Audio Outputs, XLR Connector Pinout, OUTPUT 1- Subwoofer Output

Audio Inputs

On the rear panel, there are two female XLR line-level inputs marked INPUTS below the connectors and designated A and B above the connectors. Connect the line-level analog audio inputs to these connectors. Input sensitivity can be selected from the Setup Menu; selections are 1.5 Vrms/6 dBu, 3 Vrms/12 dBu, 9 Vrms/21 dBu, or 18 Vrms/ 27 dBu. These values correspond to the maximum input signal level that can be applied to the inputs without clipping. The signal's source impedance should be less than 600 ohms.

We recommend balanced connections be used. Balanced connections will reduce AC hum and interference, especially with long cable runs. Unbalanced connections may be suitable for short cables. The input impedance is 11k ohm for balanced connections or 69k ohm for unbalanced connections.

Audio Outputs

There are two sets of line-level outputs on the rear panel grouped as A OUTPUTS and B OUTPUTS. Each group has four male XLR connectors numbered 1, 2, 3, and 4. They are “mapped” with the following general convention:

OUTPUT 1- Subwoofer Output

OUTPUT 2- Low Frequency 1 Output

OUTPUT 3- Low Frequency 2 Output

OUTPUT 4- High Frequency Output

There are two Low Frequency outputs (OUTPUT 2 and OUTPUT 3) to allow for low fre- quency shading requirements of line arrays when operated in triamp mode. If the shading network of the loudspeaker is used, OUTPUT 2 is not utilized and the amplifiers are operated in biamp mode.

Input connectors

Output connectors

Pinout label on rear panel

XLR Connector Pinout

Shown are the pinouts for the XLR connectors. Male connectors shown, pinout is the same for female connectors. We recommend balanced connections be used. Balanced connections will reduce AC hum and interference, especially with long cable runs.

Unbalanced connections may be suitable for short cables. The input impedance is 11k ohm for balanced connections or 69k ohm for unbalanced connections.

Balanced connection pinout

1= shield (ground) 3= minus (-)

2= plus (+)

Unbalanced connection pinout

1= shield (ground) 3= jumper to pin 1 2= plus (+)

5