Lecture 05 ambisonics and Reaper, a quickish tutorial

What follows are instructions on how to make use of Reaper and the very powerful Ambisonics tool Kit to help you to spatialize your sound. It does not advise on what might sound good in a spatial context, but gives you the building blocks to be able to construct spatial worlds and effectively bounce them to stereo, binaural, bFormat and surround.

It’s important to first setup your space so that you can monitor the effect of your work effectively.

You all now know how to build a surround rig, if in doubt, here are the  ITU guidelines on surround speakers placement and how to use your sub (though not position it) correctly.
www.itu.int/rec/R-REC-BS.775-3-201208-I/en
www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.775-3-201208-I!!PDF-E.pdf

Reaper and the ATK

It is a good idea to watch the initial tutorial videos here led by the super-helpful and impeccably clear Trond Lossius:

www.ambisonictoolkit.net/documentation/reaper/tutorials/

certainly, check this one out;

As we go on, we’ll also dip into some command line processing using SoX sox.sourceforge.net/ and we’ll pull down some nice bformat IRs from the openairlib: www.openairlib.net.

Watching the videos, use a pair of headphones to get the best effect, most of the signals coming from Reaper are binaurally decoded.

Intro video

A quick introduction. You’ll need to download and install the following if you want to follow along.

REAPER:  www.ambisonictoolkit.net

Ambisonics Took Kit (ATK for Reaper): www.ambisonictoolkit.net

CREDITS: Flute playing in videos is from a session with Richard Worth. We were in my studio in Alison House, rehearsing for a performance of gruntCount.

Ambsionics – encode Mono, decode Binaural

Ambisonics – encode Mono, decode surround

Ambisonics – create a bFormat world that you can move around

Ambisonics – create a bFormat reverb

You’ll need to download some bformat IRs from here:

www.openairlib.net/auralizationdb?keys=&field_space_cat_value=All&field_generation_value=All&field_format_value_many_to_one=B-Format+%284+Channel+Files%29

You’ll also need to paste at least this little bit of code into SoX on the command line, or to make use of your own tools for splitting and renaming soundfiles en-mass. First, open the terminal, type “cd ” then drag and drop the folder where you placed all of your bformat IR files, then run this:

for i in *wav; do echo $i; sox $i ${i%%.wav}_WX.wav remix 1 2 ; done && for i in *wav; do echo $i; sox $i ${i%%.wav}_YZ.wav remix 3 4 ; done

Ambisonics – create a bFormat reverb to send to

 

Ambsionics – rendering regions

 

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