Neat. What is the display on the top left box saying?
The top silver box is a custom home theater PC. A-Tech Fabrication built the beautiful chassis for me, and I put the PC together, wrote a module to display stuff from JRiver on the VFD you are asking about, wrote a module to control and display volume, etc...
Xilica is good stuff. I assume you have a fully active setup. More details please.
Correct, I completely removed the passive XOs from the speakers. The high-med-low filters are all FIR (main benefit of the XD series over the XP series), and the woofers also cross (low order bessel filter to minimize any impact on phase) to 5 time aligned and level matched subwoofers to even further lower distortion. Five subs are not for more SPL, but to further lower distortion caused by room effects (such as ringing and any nulls below about 200Hz). Minimizing room issues allowed me to have a response like this without any EQ (no kidding), and a LF decay time that is world class (as in very tactile and realistic). It seems very few people can setup subwoofers to sound good, but no worries, I use REW (Room EQ Wizard) and do it correctly. The five subs are also elevated off the floor so as to improve the waterfall plot even more.
You can see a sample of the THD measurements here (measured acoustically at the main listening position). Even very low frequencies remain well below 1% (20Hz is close to .44%), with 80Hz at .23%. Most of the mid-range is below .1% at 90dB. If you are used to electrically measured THD this sounds high, but remember it includes the room impact too so it is actually very impressive.
The volume is handled via an RME HDSPe 16in/out AES PCI-e card and the wonderful RME Totalmix application using RME's ASIO driver for Windows 10, and it uses an internal 42 bit DSP on the RME card! Volume is controlled and displayed by my home automation server over the network by talking to the RME Totalmix application.
http://www.rme-audio.de/en/products/hdspe_aes.php
Right now, I am using 6 channels from the RME PCI-E card that feeds the Xilica XD4080s using AES (to minimize any unnecessary D/A and A/D conversions). The 5 of the 6 channels feed 5 speakers that are each actively tri-amped (so 10 amps were needed), and the other channel is a mono signal that gets split to 5 outputs, then delayed and level matched appropriately for each of the five subs. This took 3 Xilica 4x8 units, the one rack just shows two. There is a rear rack for the rear speakers that has a third XD4080.
Of course the PC is optimized to lower latency, and I'm using Windows 10 LTSB addition to get rid of the stuff MS puts that no one wants. All connections are made using custom length cables I made using Canare Star-Quad cable and are housed in custom racks I built. Even the power cables were cut to minimize length and keep things tidy.
The PC can also do UHD playback (I use JRiver and MadVR for video rendering). It just can't decode Atmos, but hopefully someday there will be a software based Atmos and DTS-X decoder.