Another possible approach is to use a standard 1st order microphone set in the far field and add panned in (at third order) signals from close mics from each of the instruments. These will need to be delayed to match the distance to the main POA mic. It might also be necessary to some second/third order components corresponding to early reflections but this would have to be experimented with. It won't be perfect but it will be closer to the output from a true third order mic than using Harpex - and without the processing artefacts.
Dave On 22 November 2013 22:23, Michael Chapman <s...@mchapman.com> wrote: > > �David Pickett <d...@fugato.com>�wrote: > > > > > > > >>> How does one record in third order (or indeed any order above first > >>> order)?�� > >>> What kind of microphone array does one need, for instance, for 3rd > >>> order with no height information (WXYUVPQ)?� > >>> Is there a "native format" method for HOA or is it all extended A > >>> format, with conversion through matrices? > > > > I don't dispute Eric's very short, but very full summary > but I think we may be at cross purposes. > > Richard Furse's software obviously works with a higher order microphone > (if anyone has one) but I would suggest his primary motivation was for > synthesised higher order soundfields. You can obviously create a synthetic > soundfield of any order you want. > > Michael > > > > > > All excellent questions. �It is not quite as obvious how to record any > > order of Ambisonics above first order. �It will require some sort of > > microphone array and post-processing. �One of my favorites is the array > > described by Craven, Lawe and Travis in: > > Microphone arrays using tangential velocity sensors > > P.G. Craven, C. Travis, M.J. Law > > We introduce a new class of 3D microphone arrays that use symmetrical > > arrangements of tangential velocity sensors.� Use of velocity sensors > > allows these arrays to recover spherical harmonics of a given degree with > > less low-frequency boost than when using pressure sensors only.� As an > > example we present a symmetrical array of twelve velocity sensors that > > resolves the eight harmonics of degrees 1 and 2.� A second-order > spherical > > microphone can now be constructed by combining this array with one or > more > > pressure sensors that provide the missing harmonic of degree 0. > > > http://ambisonics.iem.at/symposium2009/proceedings/ambisym09-craventravis-tangentialsphmic.pdf/at_download/file > > > > > > The other practical method for constructing an array that produces higher > > order spherical harmonic outputs is to use a group of omnidirectional > > microphones on a sphere, such as the commercially available Eigenmike: > > http://www.mhacoustics.com/products > > > > > > There are other methods. �It's still early days for this technology. > > > > Eric Benjamin > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: > > < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20131122/1436acf9/attachment.html > > > > _______________________________________________ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20131123/f50985b7/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
