Sennheiser Ambeo and Harpex in Nuendo 8

Hi there!

Does anyone have experience using Sennheiser Ambeo mic’s A-format audiofiles and converting them in Nuendo 8
to standard formats (st, quad, 5.1…) using the Harpex convertor as VST-plugin?

Been running some tests and all went smoothly, except when decoding a test-recording in A-format to standard
surround, where I am not entirely sure if I routed things correctly as a) the resulting surround image sounded awkward
and b) the Harpex’ input only showed two of the four channels receiving signal.

So please allow me to explain my steps:

-inserted quad-file with Ambisonic recording in A-Format to a quad track.

-routed quad track to 5.1 group track.

-inserted Harpex plugin to that 5.1 group track.

-In Harpex: Input mode: Ambeo / Output mode: surround / Preset: L,R,C,Lfe,Ls,Rs

This 5.1 group track then gets routed to the 5.1 main out and this should give us the correct 5.1 conversion,
unless I overlooked something.

Any input would be greatly appreciated, if only to confirm that my routing is right or wrong.

Big thanks in advance,



  1. add one Quad audio track for the WXYZ source audio.
    2)add one 5.1 group track - add quad child track to that group in VST connections
  2. insert your WXYZ decoder on that 5.1 group (same for if you like to break it out into a 7.1 )
  3. bus your source WXYZ track to the quad child bus input of that 5.1 group track and that’s all you would need to do.
    either send you 5.1 group to a 5.1 record track or bounce it out

    Screen Shot 2018-01-18 at 11.01.16 AM.png

Hi there, thank you very much for your clear explanation! I tried it out, following your guidelines, but unfortunately
it did not work correctly with this signal. The Harpex (on the 5.1 group track with the 4.0 childbus inserted as you suggested) showed only two
signals in its Input channel display, while it should be four. Unless I misunderstood something, of course.
On the other hand, the people at Harpex told me to just insert the quad audiofile (with the WXYZ source audio) onto a 5.1 track which had the
Harpex inserted. I tried that, and it worked! I am not technical enough however to understand the logic behind this, I readily admit…
But cheers anyway!