New to Nuendo, having an issue with routing third-order ambisonics (“3oa”) to stereo.
Specifically, I use a third-party plugin to downmix HOA ambisonics to stereo. Nuendo ships with the VST AmbiDecoder, which has similar uses and can be used as a plugin or as a channel panner, but I want to use my plugin instead for its variety of advanced options.
I have to run this plugin on a 3oa track, 3oa group or 3oa FX bus. (If I place it on a stereo stream, it obviously does not receive multichannel ambisonics input.) When I route the “stereo” output of my plugin to any form of stereo group or output, Nuendo adds VST AmbiDecoder as a channel panner, double-processing and mangling the output, and I cannot bypass this channel panner.
When the plugin is on a 3oa track, group or FX bus, it receives its 16-channel ambisonics input, and outputs 16 channels, with channels 0–1 containing my preferred L/R stereo downmix as expected, and with channels 2–15 silent. But as far as Nuendo is concerned, this is still a 3oa datastream.
If I then route the output of this track, group or FX bus to a stereo group or output, Nuendo adds a VST AmbiDecoder channel panner, which treats my two stereo channels as AmbiX 1-2 (W-Z) and double-processes them, breaking my downmix.
Naturally I tried to bypass the AmbiDecoder channel panner. When I turn on “bypass”, the panner displays as yellow on the channel strip, but it remains active and continues to double-process my sound. So the bypass has no effect.
I tried using Direct Routing slot #2 to send to my stereo output instead (main output routing using either “No Bus” or a throwaway 3oa bus), but in that case nothing goes to the stereo output at all. I tried using a Send to a stereo group, but the result still appears to be a double-processed signal.
I tried different channel panners (only other choices for 3oa-to-stereo routing were Anymix Pro and MixConvert V6) but none would work.
Ideally, my third-party plugin would be usable directly as a channel panner in Nuendo, as in this case it is serving that very function. Unfortunately, this is not an option.
It should be fundamentally simple for a DAW to take a 16-channel stream and route channels 0–1 to channels 0–1 of a 2-channel stream (would be easy in Reaper), but I can’t figure out how to do it in Nuendo. So I have to assume I’m missing something easy and obvious.
Is there a best practice here? Or a workaround? Is there a third-party channel panner that can treat 3oa as generic 16-channel audio and do custom channel mapping/mixing (0=0, 1=1) or just a 1-1 mapping with truncation?
I raised this matter with Steinberg, and they said they do not provide technical support for Ambisonics routing, suggesting I ask here. I saw a similar topic about third-party ambisonic plugins, but it seemed to be a different issue.