macOS choose digital output of multichannel usb interface

Roon Core Machine

macOS 11.4 MacBook Air, M1, 16GB

Networking Gear & Setup Details

wired Ethernet

Connected Audio Devices

Native Instruments Komplete Audio 6
SPDIF output to Neumann KH 750 DSP

Library Size

Description of Issue

The USB interface has 6 outputs. Out 1/2 analog, Out 3/4 analog, Out 5/6 SPDIF.
Roon uses only the analog Out 1/2.
On macOS I can choose them in the Audio MIDI, but Roon don’t uses that settings.
How can I choose digital Out 5/6 in Roon ?

Hi @Karsten_Heinze and welcome to the forum.

You can try to setup a Procedural EQ in the DSP section of your zone and add a channel mixer operation:

See also:

If this doesn’t work for you, you may be stuck with your Audio MIDI Setup and have to direct Roon to use this (standard?) device as output.

I tried the Procedural EQ, but still no output signal an the SPDIF

Using the standard device as output crashes Roon.

Sorry for the delayed response here, @Karsten_Heinze

Can you share a screenshot of Device Setup?

Do get any error messages? If so can you share a screenshot?

1 Like

Just wanted to note that I had a chat with our ecosystem expert on this, and he suggested ensuring that 7.1 is selected in Device Setup. Can you confirm?

Sorry for the late reply.
In MacOS Audio Device Setup there is only Stereo, 2.0 Surround or 5.1 Surround.
In Roon Audio Setup there is only Channel layout 2.0 or 5.1.
There is no place to choose 7.1 and I don’t want any Surround, just Stereo.

Would this help? (They make a couple of other apps that might): Rogue Amoeba | Loopback: Cable-Free Audio Routing

Doesn’t help I tried their free and also bought the AirFoil software.

Hello @Karsten_Heinze,

A. Set Channel layout to 5.1.
B. Go to DSP settings.
C. Add Procedural EQ filter.
D. Add “Mix” operation.
E. Go to output channel “5”, set it to use input channel “1”.
D. Go to output channel “6”, set it tou se input channel “2”.


Did A to D, see screenshots.
Still no output on the S/PDIF 5/6.

Hello @Karsten_Heinze,

Could you provide a screenshot of the device in Audio MIDI


Screenshot 2021-07-30 at 12.55.21