For encoding four-channel programme material (left, centre, right, and surround) into two-channel Dolby Surround format for use on broadcasts, commercials, videos, TV productions, CDs, and video games. Used with SDU4 Dolby Surround Decoder for monitoring.

• Balanced XLR inputs for left, centre, right and surround and balanced XLR outputs for left total and right total outputs • Balanced XLR sends and returns for EPL (External Process Loop) • S:N ratio > 80dB • Frequency response 20Hz-20kHz • 1U rack-mountable