I get a lot of questions about the system. I’ll attempt to answer the basics here.
Main Control System
We currently use a QSC Core 110f DSP system. It’s an 8 (in) x 8 (out) x 8 (in or out) DSP frequently used in commercial AV deployments. Its tremendous flexibility, power, IO capabilities and scripting ability has enabled us to push it well beyond the bounds of just an audio processor.
The control schematic is incredibly complex and beyond the scope of this page. It also has thousands of lines of LUA script to make it do all sorts of things we never dreamed of.
We also recently acquired a (discontinued) AtteroTech unD32 – a 32 channel Dante / AES67 break out box. So at some point I will be able to expand the unit to a (theoretical) 40 channels.
I Can’t Hear You
I went looking for a 24 channel amplifier. Yes, they exist – from the basics like this Apart through to the amazing d:24 but these weren’t affordable.
So someone (looking at you Grant) stupidly suggested we should build one. So we did. I sourced a box of TPA3116D2 amplifier modules and slotted them in a rack enclosure on a couple of decent switch mode supplies. Sure was a hell of a lot of loom wiring. Pulls about 20A (24V) peak when the Tree is at full swing.
Speakers
These are generic transparent Mylar speakers. The initial version had two LEDs in reverse parallel wired across them and a holographic sticker to catch the light.
Version 3 (currently in production) has a custom PCB to house double the number (front and back) of SMD LEDs along with a better current limiting system and an additional “pad” to reduce the impedance of the speaker (they are too efficient and we need to increase the voltage from the amplifier to drive the LEDs without blasting the speakers).
Sensors
Interaction is a big part of the system. This was achieved by using a handful of small PIR sensors mounted in electronic enclosures and then interfaced with the QSC Core GPIO (and some more code).
Power
Site power has proven to be one of the biggest issues to date. From faulty generators, missing trenches to stolen gear.
From 2023 it is our plan to build “The Ra Accumulator” – a scalable solar system specifically for our art installations.