These are the active version of the acclaimed S400 with lots of useful features. Here's a good review:
https://darko.audio/2020/09/a-long-film-about-the-buchardt-audio-a500/Helpful comparisons to LS50W and Elac ARB-51. But you really need the hub to open up all the possibilities. Wonder why the hub has 3 optical inputs, but only 1 coax, usb, HDMI (ARC), and analog (RCA) inputs? Does Fletcher-Munson loudness correction - something I've thought about for 40+ years. DSP crossover also controls the performance and "health" of each driver. The wireless connection (24 bits/96 kHz) works without a network and is WiSA certified, meaning it auto-confirms/corrects for transmission errors. And the hub also offers unique room measurement/correction.
The A500 is sealed and operates as a 3-way (for response down to 25 Hz, +/- 1.5 dB) or 2.5-way (for highest output) using what they call Master Tuning via a USB flash drive with future variations promised. Of course it offers controlled directivity. Each driver has it's own sub-enclosure and DAC. The DSP aligns the rear facing driver with the front drivers and allows the tweeter to be placed above the mid/woofer unlike the S400.
The A500 + hub cost $4400 USD (delivered) and they do have a 45 day audition (pay only 25 euro to return). Isn't the ultimate in any one attribute but very close on many and should be very domestically compatible as several boxes are eliminated. Overall a very sophisticated product.