> Thank you Michael and Richard. It's now beginning to make more practical
> sense to me!
>
> 1. Just out of interest, when you "upsample" to Third Order Ambisonics,
> does that mean simulating the missing information?

I suppose so, but there are people on this list who could give a better
verb than 'simulate' ...

> Is it possible to
> record directly in TOA?
>
Various expt'l and less so (see (?sp)Eigenmic) methods,
but the practical answer is "No it is not possible."

> 2. Richard, you mention using the TOA Harpex VST plugin to create full 3D
> 16 channel TOA. Excuse my ignorance, but does 16 channels equate to 16
> speakers? And does this equate to 16 different speaker positions? (e.g.
> placed on the surfaces of a dodecahedron, but not on the nodes).
>
Ambisonic B-format has (2n+1) channels for pantophony (2D) and ((n+1)^2)
channels for periphony (3D).
Thus Third Order Ambisonics (TOA) has ((3+1)^2) = 4^2 = 16 channels.

B-format (storage/distribution) is not D-format (speaker feeds).
B-format
--has the minimum number of channels (useful for storage/distribution)
--can be decoded to 'any' speaker configuration (again 'useful')

First order horizontal-only B-format has 3 channels.
You will need at least a square rig (4 speakers) to reproduce it. Many
would say it would be improved by using a hexagon (6).


> 3. Do I require Jack if I am using a Blue Ripple Sound filter?
>
Leave that to Richard ... but I doubt it (not least as BR works on
Windows;-)>

> 4. Are AmbDec and Rapture 3D Advanced equivalent?
>
Totally ... holding breath for polite correction from Richard ;-)>
Seriously, of course not !

> 5. Do the speakers feed directly into the Motu Traveler (or equivalent)?
> In other words, if I hypothetically wanted to use 16 speakers (as in
> question 2), would I need something capable of having more speakers
> attached?
>
You need a soundcard with 16 'outs'.
IIRC the Traveller has
8 normal analogue outs
2 headphone outs ('L&R')
2 EBU outs ('L&R')
8 ADAT outs
The first ten are analogue, so easy.
Decoding EBU, no idea.
ADAT can be done with a ?150 / ?200 euro box.

Other Motus, you'll have to do your own research.

Ditto other multichannel soundcards.

But _if_ your 'repertoire' is fixed then a couple of Waveplayers might be
a lot cheaper ???

However TOA will need >>16 speakers ...  (so if you are going down that
path (do you need TOA?)) then you will be chaining Motus ( 1.5 to 2K
budget?) or using some other soundcard (suspect at least as much) or
cheating with 3 Waveplayers (c.700).
(BTW, don't think anyone on here has chained Waveplayers, but that it is
possible was the anglo-german consensus of reading the manuals ... the
manufacturer does answer English emails ... )

Good luck,

M


> Thanks for clarifying things for me.
>
> PS Michael, thank you for your suggestion about getting in touch with
> Eric. I will look up his posts later today.
>
>
> On 9 Jun 2014, at 12:15, Richard Furse <rich...@muse440.com> wrote:
>
>>> -----Original Message-----
>>> From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of
>>> Michael Chapman
>>> Sent: 08 June 2014 15:58
>>> To: Surround Sound discussion group
>>> Subject: Re: [Sursound] Advice on Setting up a Listening Room
>>>
>>> [...]
>>>> 4. I don't know whether I need to consider placing speakers above (and
>>>> below) the horizontal plane for the purposes I described above. It
>>>> would
>>>> obviously be more realistic, but noticeably so? If so, how many?
>>> If you want 3-D you will have to.
>>>
>>> Minimum for first order is 8 in a cube.
>>> First order may not be precise enough for you.
>>> On the other hand with a TetraMic you will only get first order.
>>> However you can massage first order to higher order (?Harpex ... but
>>> IIRC
>>> only horizontal).
>>
>> There's now also the "TOA Harpex" VST plugin, which upsamples from first
>> order B-Format to full 3D 16-channel TOA.
>>
>>>> 7. I was planning on recording listening situations using a TetraMic.
>>>> From
>>>> what I understand, I would use something like a Motu 4Pre to get the
>>> sound
>>>> into a MacBook Pro (although that all sounds not very portable),
>>> ?Tascam DR-680 Eight Channel Portable Digital Audio Recorder
>>> see the TetraMic site ...
>>>
>>>> then use
>>>> software such as Reaper with ambisonics plugins (Blue Ripple Sound?)
>>>> to
>>>> create sound files with the correct encoding on. But then I'm stuck�
>>>> do I
>>>> play those sound files through special software, or do I play them
>>>> through
>>>> something like iTunes?
>>>
>>> You need to decode them to speaker feeds
>>> IMHO on Mac, Fons' AmbDec is your friend.
>>>
>>> You can feed the output direct (via Jack) to your speakers ... or you
>>> can
>>> save it to a multi-channel file and play it back how you like.
>>> [...]
>>
>> To give you some more options: with our (Blue Ripple Sound's) VST
>> plugins you can produce (and play) speaker feeds using decoders inside
>> Reaper. You'd need "Rapture3D Advanced" for a non-standard/irregular
>> speaker layout - "TOA Decoding" targets standard layouts only.
>> Alternatively, the Rapture3D Player can be used for stand-alone TOA
>> playback. Currently you can't use iTunes to play ambisonics directly
>> AFAIK.
>>
>> Best wishes,
>>
>> --Richard
>>
>>
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