Mixers with Stereo USB Interfaces

[RexBeckett]

The USB connection on most of Behringer’s range of small analogue mixers provides a stereo bi-directional audio interface. The USB Send (for recording) is taken from the mixer’s Main mix. It does not allow recording of individual inputs/channels – other than by panning them to extreme left or right. On most small mixer models, the USB Return (playback) can be routed to either the Main mix or Control Room outputs.

If the USB/2-TR to Main Mix button is pressed, the USB Return is added to the Main mix. The USB Send is muted to avoid the possibility of digital feedback.

If the USB/2-TR to Control Room/Phones button is pressed, the USB Return is routed to the Control Room and Phones outputs replacing the normal monitoring feed. The USB Send is not muted.

This arrangement works quite well for simple recording and playback tasks but is not so suitable if you need to monitor a mix of playback and live inputs. This is essential for over-dubbing and may be required for some streaming applications. Here are three possible solutions:

Use a headphone amp or monitor speaker that has dual inputs. Connect the mixer’s Main output to one input and the Control Room outputs to the other. Press the USB/2-TR to Control Room/Phones button on the mixer.

Use a UMC204HD or UMC404HD USB audio interface instead of the one built in to the mixer. Connect the mixer Main outputs to the interface line inputs. These interfaces have a monitor mix control that allows adjustment of the relative levels of playback and live levels. The UMC HD interfaces also have dedicated drivers that provide ASIO support which can reduce latency with most DAW software.

On the mixer, connect the 2-Track Input to the 2-Track Output using a pair of short RCA/RCA cables. Press the USB/2-TR to Control Room/Phones button on the mixer. The mixer sums the 2-Track input with the USB Return and sends the result to the Control Room and Phones outputs. It will be necessary to use the PC level controls to adjust the volume of the USB playback relative to that of the Main mix.