So, I ordered the Violons.
Good for you!
I need to think about how I am going to drive them with my own meagre SET's...
Others have given comprehensive info.
My info comes from playing with Violons (& Campanile) using Mahler 5 (Barbirolli) & 2 (Klemperer), and a few other things. So, driving Violons & the Mahlerian or Wagnerian Orchestra:
1) You know and I can confirm that reproducing the musical illusion and impact of a full Wagnerian Orch is tricky. Worse, a fully blown Mahler 8.
2) Tricky No2: you have one unit and no horn, for mid and down.
The applicability of ONE amplification unit, working seamlessly fm dc to daylight, is questionable. You need to use two channels/side. However, this is tricky to do as the xover is set very high (normally you'd need the extra horn to go down to, say, ~100Hz) which means, well engineered amplification. So, I recommend you settle for ANYthing that can produce acceptable/good lower mids to mid-bass with yr speakers (i.e. ~60Hz upwards, this applies even with the "bass enhanced model, whatever they call it -- which is the one I played with). Many diy options in Ozz... so, do try. When find a selection of products that seem to work it's all about finding the one that blends sonically w/ yr SET. Forget the 40Hz range for the moment.
3) "What would be nicer":
If you could use an active xover with adjustable slopes, phase and attenuation prior to the amps -- despite the existance of the passive.
4) Depending on yr room & set-up possibilities, you may need to incorporate separate woofs (the ubiquitous "sub" woofs).
5) Check points:
Amplification: refer to upper mids & lower-mids as they are portrayed together, i.e. the piece you're listening to contains both ranges. Forget mids for now, and forget transparency/ amount of detail, etc. Focus only on how realistically these two ranges sound.
Positioning: work on getting the mid-bass right and the bass (such as it is) should suddenly appear out of nowhere. It's a matter of "coupling" the 2 lower units; there should be an optimum positioning range for this in yr room. In some cases, it;s a matter of less than 1". You;re playing w/ wavelengths is all -- no rocket science.
TO simplify things with the Violons, I used ss class A everywhere. I also tried hi-ish powered SETs everywhere (KR). I used the same amps for all channels; I also tried a very cheap xover (simply, a Behringer, that was laying around). I used a TVC, so no active pre stage. All of this was at a dealer's where equipment was readily available.
The result CAN be good, even on Mahler 8! I didn't use subwoofers -- but could have, most usefully so. I couldn't play very loud & this is relative to room size of course: when the ppp was easily discernible, the ffff was simply compressing. The room was large (~80 m2).
Cheers