I liked the single XLR subwoofer output--you can set up linking the Sub with the Main and/or either of the Alternate outputs. There are seven stereo input sources: three analog XLR line-level inputs, both AES and USB digital inputs, and plus a Bluetooth receiver input that is paralleled using 1/8-inch mini unbalanced analog jacks front and back panels.

Bluetooth connectivity is very handy for quickly playing music directly from cell phones. Artists and producers love this capability just to play ideas right from their phone--less work too--no importing audio files required.

All analog inputs use API 2510 op amps and the stereo outputs include full mute, mono, and dim functions. There are two stereo headphone outputs switchable between the Control Room (C/R) and a Cue Source selectable from any of five inputs.

The nice looking API lighted push buttons are easy to see as is the large 18-segment LED stereo monitoring meter and the API 41-detent Control Room Knob right in the middle of the action. All connections are on the rear panel of the MC531 that's all powered by an external multi-voltage power supply.

The API MC531 will bump up your current monitoring accuracy and studio to a professional level and is backed by a five-year warranty. It sells for $2,495 MSRP.

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