To top off the "discussion" I took the liberty to confirm with Daniele on some aspects of what I have been writing:
First of all the room is going to completely dominate bass performance and extension. With that said The Caravaggio is flat to 20Hz, 10Hz is ~18dB down. What you need for significant output at very low frequencies is just move massive amounts of air. Daniele has never managed to break a ribbon even with driving amplifiers into clipping.
From my POV:
With subwoofers, to get flat response down to 10Hz or even lower you really need EQ with lots of power. You need to drive a driver to large excursion working against the enclosure air volume. You could also design a port with say a 10Hz resonance. In case of planars there is no enclosure which probably makes a difference. My Rel subs only allowed to set a crossover point, so I would set these at a low frequency, reducing their upper bass response to get more relative low bass response. There may be some undisclosed EQ in them, likely is. The Velodynes allow you to apply EQ and even room correction, so you can get down there easier and they have steeper crossover slopes. The Wilson XS subwoofers are a bit of a different story having 2 18" woofers in a humongous enclosure with very low port tuning, those could really dig low without EQ boosting, from memory those would start rolling off at 18Hz naturally. I have a photo somewhere I will dig up to indicate their physical size.
Now this is all fun discussing, but I did not buy Alsyvox speakers for Bass performance. Having fond memories of having owned Apogee Full ranges in the past, I had placed myself on the waiting list for a refurbished pair of Full ranges from Henk van der Hoeven, who is the dutch Apogee restorer, after hearing a refurbished pair of Diva's in Paris around 6 months ago. The plan was to use these with the Wilson XS subwoofers as a fun system
@home. Now this was going to be a multi year project but then the opportunity "fell into my lap" to acquire Alsyvox Botticellis (thank you Bob). Upon their arrival their Bass performance was a shocker and totally took me by surprise, a very nice surprise indeed. So meanwhile I have cancelled the Apogee Full range order and had my local dealer resell the Wilson XS subs.
Now what sparked this discussion for me was the idea of adding subs to the Caravaggio Single, you really do not need them, they are not going to add anything unless you go all out on huge subwoofer towers, my Rels / Velodynes do not even move close to the same amount of air as just the Botticellis do. With the very important caveat that in my 66m2 room their response is actually flat to 23Hz. I do completely appreciate separate powered subwoofers have the ability to EQ to adjust for room imposed deficiencies. I would personally not apply EQ to the Alsyvox panels as I would not want to compromise their transparency and speed but there's of course the option to do that if so desired. For that I would most definitely move to the Caravaggio though and power the subwoofer panels separately. And who knows I may end up doing that when we get them in house in our new room
