[OT] immersive - surround vs. multichannel vs. quad

Hello,

Though I mostly do 2-track music today, I have worked in this field some time ago but be warned, my thinking of the problem is quite different to what you hear usually ...

Doing what you want quickly and without spending too much is really possible. For example, you can buy a M-Audio Delta 44 (about 155 euros) audio interface and connect it to four cheap small powered speakers, this will work at home or for "chamber music".
You can also find some cheaper multichannel sound cards, like the ones used by the gamers. I have met a sound engineer that knows how to use such interface with Reaper for doing multichannel audio mixing sessions.
If you buy new speakers, the cheapest look like being the Behringer MS-16 (48 euros each) but I don't know how they sound.

When it comes to positionning the speakers, there are some things to consider:

1. Some international standards exist for placing the speakers. When it comes to stereophony, only two of them are widely used: two speakers (2/0/0) and six speakers (3/2/1), this one often being called "5.1 surround". Respecting these standards help you playing back your music on common speaker systems ... If you have 4 speakers, for example, you can place them like the L, R, LS and RS speakers of a 5.1 surround array, so your 4-track music will sound equally good on standard 6-speaker arrays.

2. During a performance or an installation, you are free to place the speakers where you want, as it's part of the composition. In this case, there is no rule but then it's often impossible to play back your music later on common systems if you don't take some special precautions about it (like defining a downmix method when composing the track).

3. I personaly don't like big circles of 6 speakers or more, for these reasons:

- everybody is just doing this, often without having any reflection about speaker position as a part of the composition
- I prefer to put at least one speaker in the centre of the circle (for example, you can take the "C" speaker of a 5.1 system and put it in the centre of the speaker circle), as it allows far more spatial effects than a single circle
- When you really have many speakers you can think of putting them at different heights too.

4. Even if there is a subwoofer, all other speakers should be broadband for better immersion.
But these tiny satellite / big sub systems have the advantage of being very compact.

5. In non standard setups, you can use speakers that are not all the same (and it helps findong more speakers).

6. There are a lot of spatialisation approaches (panning, ambisonics, Ircam, micro-time decorrellation, etc). Don't hesitate to investigate several techniques.

Regards,
-j

PS - about "3) just use four speakers for output and process the mono source material spacially (binaural)."
Binaural processing is mostly good for headphones and it's two-track anyway. "Transaural" processings transform a binaural recording to something you can play on speakers with a similar effect, but only at a very small sweet spot in the room ...

Quote: johnhudak@gmail.com wrote on Wed, 17 September 2008 05:30
----------------------------------------------------

> i am basically questioning the immersive idea though...whether it is
> possible to do it cheaply and quickly.
>

I'd have a look at ambisonics, like so:

http://www.icst.net/index.php?show=137

If you could set-up speakers at the corners of a cube (six channels), you can get a really nice result. Julien mentioned some cheap gear; borrowing gear is even cheaper.

You could also have a look at VBAP, search maxobjects.com.

I also agree with Julien that installations are an opportunity to create your own, site-specific speaker arrangement. The speakers don't need to match, or even be "good" by audiophile standards.

mz

Thanks everyone so far for the great information! After I posted this, I
realized that I might get my head chewed off for not doing a thorough search
through the archives; but after doing a search, I found that I didn't get
the particular answers I wanted from the search.

So I found that this museum that is going to sponsor the installation has a
bunch of 5.1 DVD players, so this makes it a little bit easier in choosing
what to use for playback. So I discovered that Final Cut Pro can actually
burn 5.1 DVDs, and the people I'm working with have a 5.1 DVD player as
well. So all I have to do is figure out how to make the sound spin around
the 5.1 space with a particular MaxMSP patch that I don't know yet, and then
how to output the 5.1 audiofiles into separate tracks. Can MaxMSP do
multichannel recording? Maybe I could send the output to Soundflower and
then take it back into Ableton Live to record? Has anyone done this
before? The spinning sound around the speakers must almost be a cliche by
now.

It turns out that I have stereo recordings to work with as well as
mono...these are old cylinder recordings, so I can't really go back and
re-record them, although that would be an interesting task.

Thank you all for the continued ideas!

Best,
John

--
http://www.johnhudak.net

Birds and insects huh?

Well, conceptually you could do worse than spatializing with some sort
of flocking algorithm. Search list for "Boids".

In answer to your second paragraph, you don't really need any software
besides Max to do everything except burning the DVD. It's just
learning how to do it. I don't know what your time constraints are
like, but if you are asking things about Max's capabilities for
multitrack recording I might suggest getting some programming
assistance if this thing is coming up quickly.

Making spatialization sound good is a multifaceted task and takes good
ears and deft programming to not sound lame. For a natural sound
things like air absorption and elegant reverberation can be key. The
multichannel backbone is the easy part.

bt

barry threw
Media Art and Technology

San Francisco, CA
Work: 857-544-3967
Email: bthrew (at) gmail (dot) com
Web: www.barrythrew.com

On Sep 17, 2008, at 6:23 PM, John Hudak wrote:

> Thanks everyone so far for the great information! After I posted
> this, I realized that I might get my head chewed off for not doing a
> thorough search through the archives; but after doing a search, I
> found that I didn't get the particular answers I wanted from the
> search.
>
> So I found that this museum that is going to sponsor the
> installation has a bunch of 5.1 DVD players, so this makes it a
> little bit easier in choosing what to use for playback. So I
> discovered that Final Cut Pro can actually burn 5.1 DVDs, and the
> people I'm working with have a 5.1 DVD player as well. So all I
> have to do is figure out how to make the sound spin around the 5.1
> space with a particular MaxMSP patch that I don't know yet, and then
> how to output the 5.1 audiofiles into separate tracks. Can MaxMSP
> do multichannel recording? Maybe I could send the output to
> Soundflower and then take it back into Ableton Live to record? Has
> anyone done this before? The spinning sound around the speakers
> must almost be a cliche by now.
>
> It turns out that I have stereo recordings to work with as well as
> mono...these are old cylinder recordings, so I can't really go back
> and re-record them, although that would be an interesting task.
>
> Thank you all for the continued ideas!
>
> Best,
> John
>
>
> --
> http://www.johnhudak.net

Hi,

why do you output the resulting sound via Soundflower to Live ?

You can record a multichannel file inside Max/Msp using QuickRecord
under the Extras Menu.

All the best

--
Alessandro Fogar

http://www.fogar.it

2008/9/18 John Hudak :
> Thank you Hans!
>
> And again, thanks to all of you who answered my questions!
>
> I came upon one solution, that may work for my particular situation:
>
> http://cnmat.berkeley.edu/library/max_msp_jitter_depot/
>
> panhandler~ does a perfect job of spinning the sound around 4 to 8 speakers,
> with adjustments for speed and direction.
>
> With Soundflower, I can route the speaker outputs through to Ableton Live,
> and record the result in separate channels. With the separate recordings, I
> can drop them into Soundtrack Pro/Final Cut Pro/Compressor; and, if the
> documentation is correct, burn a 5.1 DVD playable on most current DVD
> players. The only problem I have is monitoring the spinning around the
> speakers, as I don't have a multichannel interface, nor a 5.1 speaker
> setup. I can listen to it after it is burned onto DVD through a DVD player
> that has 5.1, so I'll have to do various tests to get it right. Also,
> panhandler~ doesn't, of course, take into account the subwoofer in a 5.1
> setup, so I'm assuming I can just play the unaltered soundfile through the
> subwoofer whilst the other 5 speakers are spinning (i.e. output 5 channels
> to Ableton, and use the original file for the subwoofer channel). [note:
> cnmat also has an 8 track recorder module that may allow recording from the
> panhandler~ patch right into the 8 track recorder patch...if one doesn't
> have Ableton, that would be a great solution]
>
> Again, the friend I'm helping out wants the spinning effect, but I'm sure
> after he hears it, he will be convinced it is much too much of an "effect";
> but, who knows.
>
> From the cnmat website, there is a page for "third party externals," where
> one needs to follow the link to get the VBAP externals that are needed to
> run panhandler~
>
> panhandler~ could also work directly through a computer multichannel
> interface if it is available, and I'm sure it would work fine. Previously
> in this thread, a 4 channel M-Audio interface was recommended. Does anyone
> else have any recommendations for other interfaces? I've seen people using
> the MOTU interfaces, but have never used one myself. It used to be they
> were rather expensive, and probably are still quite expensive; so if someone
> knows of any affordable 6-8 channel interfaces, please let me know.
>
> Best,
> John
>
> P.S. I'll have to check out the 4.6 examples folder...5-point-1-fun may
> prove to be just as handy.
>
> On Thu, Sep 18, 2008 at 2:48 AM, hans w. koch wrote:
>>
>> in max 4.6 there was a folder called "5-point-1-fun" in the examples
>> folder.
>> don´t know about max 5 (yet)
>>
>> h
>>
>> www.hans-w-koch.net
>>
>>
>
>
> --
> http://www.johnhudak.net
>
>
>

a couple of thoughts...

1. sound cards:

Presonus make some good cards that are reasonably priced. my experience with m-audio drivers has generally been pretty bad, but YMMV. MOTU is probably better in terms of sound quality, but more expensive.

2. recording multi channel files:

this is easily done in msp using sfrecord~, although you could do this with buffer~ but it would eat lots of RAM. create an sfrecord~ with an argument to determine the number of channels you need, then you route all the outputs of your panning algorithm to the appropriate inlets. hit record and save as a multichannel wave / aiff file, bear in mind the limit is 16 channels (i think!). Then you can open the file directly in sound track pro and export via compressor for DVD (ac3 format)

this method avoids using soundflower / live which can cause latency problems.

hth,

j