How to Set Up a USB Mix Minus

by Rob Scheerbarth | Mixers & Interfaces

Mix minus is a method of describing audio output coming from a mixing console. When using this setup, the output contains everything except a single input.

Whether used through USB or more traditional options, it prevents delays, echoes, and feedback that occur during audio events. If you’ve ever heard the delay when someone calls into a radio station and they don’t turn down the volume on their receiver, a mix minus can remove this effect from a podcast.

You can also use the USB mix minus technique to eliminate those audio issues from live sound, video conferences, and telephone interviews.

How Can I Get the USB Mix Minus to Work?

When using a traditional setup, you’d need the following with an audio mixer to have the mix minus function correctly.

Digital or analog audio mixing console with a minimum of one AUX output or an FX Send.
Cables and microphones for the primary mix.
A headset adapter cable, 1/8-inch cable, and dual 1/4-inch cables.
A computer or phone for the remote guest.

You’d start by connecting the microphones to the system, then set the correct gain for the primary mix.

Your remote guest connects to the mix from their phone, laptop, or another device.

Next, the AUX output needs to get connected to the audio mixer to the equipment so that the guest can hear what comes from the mixer. Turn up the channels for each input device except for the one connected to the guest.

Once everything is ready, you can test the setup to ensure it eliminates the echoes and feedback from the audio stream. If you still get some unwanted sound, go back through the different steps to see if a loose connection is present.

What Is the Best Way to Include USB Mix Minus?

Once the RØDECaster Pro updated to its freeware version 1.1.0, selectable mix minus became available through its USB port. This feature is similar to what was already available through Bluetooth® and TRRS.

With the RØDECaster Pro’s update, the firmware now supports switchable multitrack recording. You can manage up to 14 tracks through a USB connection, and it can be either pre- or post-processing.

If you already have the RØDECaster Pro, the 1.1.0 firmware update is free.

Cleanfeed Pro, Skype, and other platforms offer an echo cancellation feature, which led some to believe that the RØDECaster Pro initially provided the same service. It didn’t until the update.

You can activate the USB mix minus option from the “Advanced” menu option.

If you activate this mode on the RØDECaster Pro, the main USB output won’t represent the entire podcast mix. Those who want to record a stereo mix to the laptop or computer and use the input for calls or similar needs will have to activate the unit’s multitrack mode. The main USB must be allocated to your communications app, then Source 1 and 2 of the multitrack device to your recording software.

How to Fix Mix Minus Issues

Although USB mix minus works well for podcasting, there can be times when the audio doesn’t seem quite right. The openness of today’s platforms makes it easier to implement this technique incorrectly, leading to a subpar result.

If your podcast audio still experiences echoes, feedback, and lag, here are some of the ways to correct the situation.

Account for Audio Variation

Some people prefer to talk right into a speaker, while others might use the speakerphone option to communicate. You can find individuals who stand far away from a microphone or place it to the side of their mouths, then others who put the equipment right up to their lips.

When using your RØDECaster Pro or another mix minus option, it helps to focus on the target’s audio level. Increase or decrease it as necessary to achieve a balanced result.

Set Permanent User Settings

If you give people control over mic levels or other remote guest functions, you’re handing over the mix minus work to someone who might not understand what needs to happen. Once you have your settings finalized, get them locked in so that they cannot be changed.

Use Automatic Settings

Gain sharing and gating are instrumental to a balanced room, especially when multiple people are recording their voices for a podcast. Mix minus uses the direct outputs to feed the matrix, so you’ll want to ensure direct outputs are set to post-gate and post-NOM. Limit the number of open mics when recording whenever possible.

A great podcast mix starts when your USB mix minus system focuses on speech clarity. You should receive natural sounds from every listening and speaking position. With this tool available, those annoying echoes and feedback sounds can disappear from your mix.

Rob Scheerbarth

Rob Scheerbarth is the owner of Podcast Rocket, the industry-leading podcast informational site. Rob has helped thousands of podcasters start and offload their podcasts, including TED speakers, Doctors, Therapists and Business owners.

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