Subs to match with Raidho XT1’s

REL T7i’s, B&W PV1d’s or SVS 1600’s?Something better in that price range? Rythmik? Input please.
If your price range is between $1-2k and you want to take the guess work out of so called matching?

This little Velodyne Plus has one of the highest levels of on board remote controlled Digital Signal Processing which provides an incredible level of Room Optimization automatically with any speaker. Or, to adjust eight parameters of EQ manually and store in six different presets to your personal taste manually.

I suggest comparing your short lists setup procedures in their user manuals to get a better idea of subwoofer advancements. 
I’ve owned subs from SVS, Velodyne, JL Audio, Seaton, Vandersteen... I am now running Rythmik with my Raidho D1’s and recommend the pairing higly.
What Rythmik subs are you running? I’ve heard great things about them and their ability to integrate with monitors.
When I had D1's I tried to integrate a Rel B3. While I got the lows I was looking for the B3 just bled too much into the mid's changing the magical mid range too much. I tried for over a year to get it right but it just didn't happen for me. The solution in the end was to get D2's.

That said as much as I loved the D2.1's which I got later I found the mids were a world better with the D3.1's. For me I heard too many D3.1's - 4.1's and D5.1's. I guess I'm too picky.
I got my hands on a PV1d and am very impressed.  I think I’m going that route now looking for a second.  Don’t overlook that sub - it is underrated.  For $1500 REL can’t match it.  I wish I could try Rythmik but I’m from Canada they are just not available here and are not on the used market very often probably because they are great.
JL e110 subs (one pair, or a stacked pair of four with two on each side) and the JL CR-1 crossover.  If you’re not crossing the Raidho Monitor over properly, you’re doing it wrong. 
Did you get a second PV1d?
Dual opposing aluminum drivers should produce fast bass and pair well with high-end bookshelf. I can't really find useful information or review about the PV1d though