Hi Richard,
The only problem I see is that straight first order decoding generally
has a different ratio of W to XYZ components that that used for third
order, which ideally should be corrected before feeding first order
material to a third order decoder, otherwise the first order material in
the mix won't be decoded optimally. Unfortunately, of course, correcting
this on the first order material in the mix (so that it is right on TOA
decoders) means that if it is then decoded at first order (say, with an
older decoder) the decode will be wrong - and unfixable, as we've discussed
before on this forum. The only full solution is to keep first order only
material completely separate from third order so that it can be handled
separately at the decoder - or, alternatively, say it has to be 3rd order
always, though I am not sure how this would work out with decoders to small
numbers of speakers.
Dave
On 22 November 2013 17:12, Richard Furse <rich...@muse440.com> wrote:
> Yes - there basically aren't any problems applying the processing
> operations
> to material that is only first order. Feeding first order material to a
> third order decoder raises more subtle issues.
>
>
> If you're working with first order material, we'd normally recommend you
> still work at third order within Reaper, i.e. set all your track channel
> counts to 16. If you force first order by setting your channel counts to 4
> then everything will work, but you won't save much CPU and you'll lose
> spatial accuracy in scenarios where intermediate processing uses second or
> third order components. When you get to your output stage, if there isn't
> any second or third order detail that you want, you can always export at
> first order by simply taking only the first four channels from the TOA mix.
>
>
> On decoding, I should start by saying we typically get good results feeding
> first order material directly into our third order decoders. We wondered
> about including an order switch here, and have done exactly that for the
> Rapture3D "Advanced" decoder plugins. However, for the normal TOA Decoding
> plugins we decided it would be better to focus on making everything work
> cleanly at third order, and encourage treatment of first order material if
> it's really needed (and IMHO it generally isn't) as folk are inevitably
> going to want to add first order recordings into third order mixes.
>
> There's a "First Order Injector" in the Upmixers library that provides a
> couple of such treatments, and an equivalent result can be achieved using
> the "Order Amplifier" and/or "Diffuser" plugins in the Manipulators
> library.
> These treatments don't attempt to sharpen the image. In contrast, you
> should
> also be able to upsample to third order using Svein's excellent HARPEX-B
> plugin, although the public version of that currently generates only
> horizontal components at third order (for compatibility with channel count
> limits in other hosts).
>
> That all said, first order material added directly to a third order mix and
> then decoded at third order is generally just "blurrier" or less sharp than
> real third order material (as one would expect!) but hopefully that's fine
> for most scenarios.
>
>
> Best wishes,
>
> --Richard
>
> > -----Original Message-----
> > From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of
> > Dave Malham
> > Sent: 22 November 2013 13:42
> > To: Surround Sound discussion group
> > Subject: Re: [Sursound] New Ambisonic VST Plugins
> >
> > Shouldn't be any problems with any of the processing operations
> (Richard?)
> > but the decoding will need to set at 1st order.
> >
> > Dave
> >
> >
> > On 22 November 2013 07:40, Bo-Erik Sandholm
> > <bo-erik.sandh...@ericsson.com>wrote:
> >
> > > Hi
> > > Is there any technical problems in using third order processing with
> only
> > > first order data ?
> > > If I remember correctly it should not be a problem?
> > > Only the overhead of having 12 unused tracks in the reaper layout?
> > >
> > > Nice of you to promote Ambisonics by offering the basic plugins for
> free.
> > > Thank you
> > > Bo-Erik Sandholm
> > > Sweden
> > >
> > > -----Original Message-----
> > > From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of
> > > Richard Furse
> > > Sent: den 21 november 2013 14:14
> > > To: Surround Sound discussion group
> > > Subject: [Sursound] New Ambisonic VST Plugins
> > >
> > > Hi there!
> > >
> > > In case folk aren't aware, the TOA ("Third Order Ambisonic") VST
> plugins
> > > from Blue Ripple Sound have been released, along with some other bits
> > and
> > > pieces. They are intended primarily for use with Reaper (Cubase/Nuendo
> > > currently can't host them).
> > >
> > > More details can be found at
> > > http://www.blueripplesound.com/story/new-toa-plugins.
> > >
> > > Best wishes,
> > >
> > > --Richard
> > >
> > >
> > > _______________________________________________
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> > > Sursound@music.vt.edu
> > > https://mail.music.vt.edu/mailman/listinfo/sursound
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> > > Sursound mailing list
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> > > 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'
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--
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'
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