1. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 1/1/ Hybrid Higher-order Ambisonic Recording Jörn Nettingsmeier Freelance audio engineer Essen, Germany nettings@stackingdwarves.net http://stackingdwarves.net

2. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 2/2/ Overview ● Quick introduction to Higher-order Ambisonics ● The problem with native HOA microphones ● Hybrid (mixed-order) recording approach

3. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 3/3/ What's wrong with first-order Ambisonics? Low angular resolution: slow off-axis roll-off.

4. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 4/4/ What's wrong with first-order Ambisonics? In practice, this means instability and a small sweet spot (= listening area)

5. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 5/5/ Higher-order Ambisonics 0 th order 1 st 2 nd 3 rd 4 th channels: 1 4 9 16 25

6. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 6/6/ Ambisonic panning

7. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 7/7/ Native HOA Microphones ● They exist. ● They work. Kind of. ● They need lots of very messy signal processing. ● They have noise and timbral issues. ● Bottomline: Ok as a shotgun replacement for dialog or maybe atmo recording, not too good as a classical main microphone.

8. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 8/8/ What to do while we wait for the perfect HOA microphone? Let's combine a first-order main microphone with spot mics panned in higher order. Main mic provides nice, coherent ambience (placed at the “best seat in the auditorium”). Spots provide HOA sharpness, stability of localisation, and enlarged listening area.

9. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 9/9/ Hybrid HOA miking ● Differs from stereo spot-miking: each instrument or “localisable unit” gets their own spot, regardless of loudness balance. ● Spots must be carefully time-aligned to the main mic. ● Spots should be highly directional, to avoid echo problems. Patterns chosen to suppress other instruments as best as possible. ● Mixing automation must be used to turn down spots selectively at dangerous moments.

10. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 10 / Hybrid HOA miking ● Worst-case situation: everyone is playing some subtle pp stuff, and a single trumpet has a sfffz. ● → Trumpet echoes all over the place, in every single spot mic. Worse the larger the area is. ● → Trumpet excites the room, each spot mike picks up reflections, which ruin the ambience image. ● Dipping the spots with automation can help. But hey, it's real life: you can't always win. Sometimes, the artifacts sound really cool. Sometimes, they don't.

11. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 11 / HOA Pop/Jazz Production

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15. (S)PACE Symposium, May 4 th Jörn Nettingsmeier 15 /