Mackie M1400/M1400i Owner's Manual - Page 17

When connecting a balanced signal using the XLR or 1/4" jacks, they're wired thusly, per AES (Audio Engineering Society) standards: Hot (+) Cold (-) Shield (Ground) XLR Pin 2 Pin 3 Pin 1 TRS Tip Ring Shield Unbalanced TS (tip-sleeve) lines can be accommodated via the TRS jack. Make sure the cord terminates with a TS plug (like a guitar plug), or if it's a TRS plug (like a headphone plug), make sure the ring is tied to the shield, preferably at the source. SLEEVE SLEEVE TIP SHIELD 2 HOT COLD 3 1 SHIELD 1 TIP Unbalanced 1/4" TS Plug RING (COLD) TIP (HOT) SLEEVE (SHIELD) COLD 3 2 HOT 1 3 2 SHIELD COLD HOT Balanced XLR Connectors RING SLEEVE SLEEVE RING TIP TIP Balanced 1⁄4" TRS Plug RING (COLD) TIP (HOT) SLEEVE (SHIELD) You can connect an unbalanced XLR cable to the M•1400/M•1400i, although this would be unusual - as unusual as an unbalanced XLR output. The M•1400/M•1400i amp expects to see a nominal signal level anywhere between the -10dBV "semipro" and +4 dBu "pro" standards, meaning almost any line-level mixer or other device can be plugged into the amp's INPUTs. Use the GAIN controls to adjust the gain of the amplifier to match the signal level you're using. If you set the AMP MODE switch in MONO or BRIDGE, use the CHANNEL 1 inputs only - the CHANNEL 2 inputs are disabled in this case. 1 CHANNEL / BRIDGE / MONO LOW CUT INPUT FILTER TYPICAL 35 Hz BALANCED OR UNBALANCED STAGE MONITOR 100 Hz OFF 170 Hz CONSTANT DIRECTIVITY HORN EQ /AIR EQ 4.5 kHz ON 2k Hz 6k Hz AIR EQ OFF TYPICAL THRU AMP MODE STEREO MONO BRIDGE TYPICAL (CHS SUMMED) OUTPUT APPLICATION FULL RANGE LIMITER (CH1 & CH2) STEREO TYPICAL SUB WOOFER FREQUENCY 125Hz ON OFF 63Hz INPUT BALANCED OR UNBALANCED 2 CHANNEL LOW CUT FILTER TYPICAL 35 Hz STAGE MONITOR 100 Hz OFF 170 Hz CONSTANT DIRECTIVITY HORN EQ /AIR EQ ON 4.5k Hz THRU OFF TYPICAL 2k Hz 6k Hz AIR EQ 17