Hey forum,

Does anybody know of good ambisonics extensions for Pure Data?

I'm trying to setup some ambisonics examples for students in a small studio (8 speaker cube), so a simple 1st order panner and decoder object should be fine.

It seems like there are ambisonics libraries available in pd-extended, but I can't see how they actually work - i.e. where is the b-format encoder and decoder objects?

PS, I've also asked this question on SO:
http://stackoverflow.com/questions/22705140/finding-good-ambisonics-objects-for-pure-data

--C.

Hey guys,

I've written an article about my ongoing research in using Pd to analyse sound from myself playing vibraphone and create a complimentary performance.

The article is here:
http://cmpercussion.blogspot.com/2008/10/duet-for-vibraphone-and-computer.html

Here's a piece that I created using these techniques:
http://www.epmartin.com/cmpercussion/DuetVibraphoneComputer.mp3

I performed this piece at the Street Theatre in Canberra as part of a larger cross-media performance involving several local artists.

I'd love to hear comments that anybody has!

--Charles Martin

Hi guys,

When I open pd-extended 0.40.3 under OS X 10.5.5 Gem is not immediately available. Is there anything I need to do to have Gem loaded by default?

Bizarrely, I have been able to convince it to load Gem by trying to create a [gem] object (not a real object) which then seems to cause the libraries to load so that real Gem objects can be loaded.

I'm using Gem to create a simple tool for displaying images of musical notation with page turns controlled by midi. The program is working really well so once I get Gem loading automatically and some kinks sorted out I hope to publish the code for everybody to enjoy!

--Charles Martin.
www.charlesmartin.com.au
cmpercussion.blogspot.com

Thanks Emacpher! That's very helpful.

Not getting anywhere with Ambilib, wrote my own bad and possibly broken objects: https://github.com/cpmpercussion/SimpleAmbisonics maybe will be sufficient!

`hoalibrary` is awesome but only for 2D speaker arrays - checking out Ambilib now: http://www.york.ac.uk/music/mrc/software/objects/

hey, I've been trying to use broadcast with netsend, but it doesn't seem to be working... does it really work?

--Charles.

well, for this particular piece I use the fiddle~ output to look for notes being played in 10 zones on the vibraphone keyboard (3 or 4 notes each). That's coarse enough to stop accuracy being a problem.

Response time would be bad if it was triggering a synth but ok for triggering complementary samples.

Actually when I perform the piece live, fiddle~ starts to react to the sound coming from the speakers and the piece starts to play itself, but I found that in the context this wasn't such a bad thing. The best solution would be to use a vibes with pickups but If I point the speakers away and have the threshold on triggering notes in the right place it can work more accurately.

I'm now trying to generalise this and use fiddle~ to listen to all 37 notes individually but it's tricky to combine an accurate pitch detection with timely attack detection (bonk is better...) as well as velocity. Then there is a problem with turning notes off.

Anyway, that's what research is for right? Solving hard problems.

Also... I've noticed midi jitter on iac bus. My solution is to be artful about what parameters I control in live so that it isn't a problem...

--Charles.

The real problem with using noteout is that notes will ring forever! you need to send notes with velocity zero (I think) to stop them.

This is why this is hard, even on a monophonic instrument. After some small delay we know the pitch and amplitude to some degree of accuracy. We also know about attacks (either from fiddle~ or bonk~), but it's hard to manage the data in such a way that when an attack occurs, significant pitch and amplitude information is send to noteout.

But what about a nonattack? how do we know when to turn notes off? You could say that if amplitude dies away the note ends, but what if you're playing legato on violin and there are several notes that occur before the amplitude dies away.

All these problems are possible to overcome, but it takes time and work.

--Charles

alright - I tried installing the same version of pd-extended on a power-pc machine and all of the paths and startup options were already filled in! Maybe something is wrong with the pd-extended intel installer? or my machine?

who knows.