This is the first didgeridoo related post on my website that is written by a guest author. I invited my colleague Nuno Pinto de Carvalho to write something about recording long didgeridoos after hearing his song on a 4.5meter didgeridoo. I had a wish to publish Nuno’s thoughts on this subject as it could give you somewhat (slightly) different angle of approach, also probably with more accessible tools. It is an easy and enjoyable reading for a didgeridoo player, but if you have any questions, please ask below in the comments. Enjoy! -Du
I am Nuno Pinto de Carvalho, a Portuguese multi-instrumentalist musician. I play didgeridoo for some time now, and lately I’ve been experimenting with long PVC didgeridoos. The reason for the use of PVC, instead of actual wood, is because it is easier to cut, modify and assemble. The PVC pipe also allows the air to flow quicker, giving a better response for the kick-didge technique (thanks to Du for his technique and help 😉 ). 
Here is a sample of the 4.5m didgeridoo sound : (problems with the audio? listen here)
Recording
For the recording I used:
- 2x Behringer-C4 microphones,
- a mixing desk with USB output (for recording directly onto my computer),
- a PC and some audio software that I will discuss later.
The best placement of the mics depends on the presence/power of the didgeridoo. For this didgeridoo I placed the mic 1 at 8-10cm from the didgeridoo opening. I used a windshield in the mic1 because of the strong air projection. (The C4-mics easily reach the peak without this protection). The mic2 was placed 50cm from the mouthpiece, to capture the breathing and throat sounds. Both C4 mics were connected to the mixing desk. Then, I calibrated the gain for each microphone so it never reaches the peak. The mixing desk was connected to the PC using an USB cable. Finally I recorded the song, through USB audio, using Ableton Live 8.
Mastering
In this section I will discuss the best configuration for my audio sample. I believe for other didgeridoos it may not be the same… Each player has to try different presets for EQ and see what is best for him. I use Ableton Live 8 because it has a very good variety of compressors, equalizers and is compatible with a lot of VST-plugins, like iZotope Ozone. First of all, I listen to the raw recording to see how it sounds. My first impression of the audio is very important, because it will “tell” me if it is well balanced and if it needs some big modifications or not. (This depends on the quality of the mics used for rec.) Remember that most people will hear your song only once. If the recording is bad they will not hear-it again, unless they are true didge lovers 😀 . Sometimes I use iZotope RX 2 Advanced to clean the audio of noise/glitches, before the mastering process.
Overview and EQ
I use Ozone’s paragraphic equalizer to analyze and adjust the frequencies, in order to obtain a “hot” sound. In the kick-didge technique, the low sounds are as important as the high sounds, to obtain a “punchy” kick. The dynamics of the kick is only noticeable if it can be distinguished from the rest of the drone frequency. If we only have low sounds, the kick will become too “bassy”, and the “punchy” effect is lost (in this case there is no contrast between the highs and lows). In Live 8 we have the recording/didge track (mic1), recording/breathe track (mic2), two empty return tracks (A Return, B Return), and the master track, with no plugins attached to it. In the two recording-tracks (mic1 and mic2) I added a simple compressor (with slow attack/release, ratio 1.5, Threshold/Ceiling level a little bellow the input), and a reverb plugin (type hall, very subtle).
Effects
The return tracks will contain the delay/reverb effects. The audio that comes from the recording-tracks (mic1 and mic2) goes to the master track and to the A&B Return tracks (and from the Return tracks to the master track also). In the A Return I added a simple delay effect, and in the B Return track I added compressor and reverb effects.
The compressor in B Return is in side-chain mode with the didgeridoo track. Side-chain mode means that the compressor (in B Return) reads the signal coming from the didgeridoo track, but applies compression to the B Return track (i.e. reverb). Compressor configuration for reverb: high-attack, slow-release, ratio 5. The Threshold level must be right bellow the input* in the more dense parts of the audio, like the drone, compressing the reverb a lot, but, at the same time, must be a little higher than the volume low sounds, like the “mouth beats” (we want no compression here). (*compressor input: part of the sound coming from the didgeridoo track, entering in B Return, passing through the reverb plug-in, and going to the Compressor) This way, the reverb effect is more noticeable when I’m playing with simple “mouth beats” (volume low sounds), and less noticeable when I’m doing the drone. (i.e. if the drone fills the sound, the compressor lowers the volume of the effects.) 
Conclusion: the overall sound is never too saturated with effects, and the audio can “breathe” (more dynamics). In the master track I added a new instance of iZotope Ozone for minor adjustments to the audio, and exported the normalized mastered audio in 32bit quality to wave file.
Post-Production
The post-production gives a bit of presence and power to the master recording, and also deals with some problems related to the Dithering, when converting from 32bit to 16bit audio, for CD production. In a new session of Live, I imported the mastered 32bit audio and opened an instance of iZotope Ozone in the master track. This time I used one of the presets available in Ozone: “General Purpose Master” and modified a little (including the Dithering option). The audio is finally ready for CD production/recording or mp3 conversion.
Thanks for reading. I hope these tips were helpful to you!
Nuno Pinto de Carvalho www.nunopintodecarvalho.com