ECHO project - Penta Sphere

ECHO project - Penta Sphere

This is another microphone array of the ECHO project. It has been invented by Anthony Caruso & Kellogg Boynton from the PlayStation Studios.

It can be used as "right in the middle" recording system or "in front of the sound source" as well.
The "Penta Sphere" has a radius around 1.3m. This should provide a great coherence with spherical HRTFs.

When capturing sounds in a circular layout, the focus of the array may be rotated so that any triplet of mics can become LCR for the image, with the option of using opposing top layer mics as a .2 for Atmos mixing.

If your sounds are coming from a certain direction, you may use cardioids as Ls and Rs.

Usually one would use a solid stand and a round plate in the middle with threads at every 72°. Unfortunately, these aren’t available everywhere, but if you know a metal workshop, they shouldn’t be too difficult to make.
We also recommend a 3/8" threaded hole on the top. You can screw a 26 cm long rod, a male/male 3/8" thread adapter and a red ball onto it.
This allows you to set up strain relief for the microphones using nylon strings—just in case the microphones you’re using are quite heavy. 
We always use strain relief to protect our equipment. But opinions on this vary widely.

In the upcoming tutorial, we will show you how to set up this interesting microphone array using commonly available equipment. It's not too easy, but it's also not too complicated. As always there will be a shopping-list available soon.