Best €2500 sub purely for music?


I recently was lucky enough to try a demo between a two rel 9tx and one s510, and I though the s510 was vastly superior. My only hesitation for being one was that the EU pricing of rels are kinda steep, and maybe im not someone best suited to use them? To explain, I use a minidsp shd preamp to control my entire system. With that I always use a high-pass filter with a extremely sharp roll off of -48db. Anything above 60hz is given to the speakers. I found this to sound night and day better than trying to cross any speaker with their natural cutoff. This is antithetical to how rel designs their subs. Lastly, it only has phase adjustments of 0 and 180. Its for these reasons why im asking you if there are any alternatives to the s510 you recommend between €2k and €3k IN EUROPE (so no svs or rhythmic or any other US brand of any sort) that might be more appropriate for a purely hifi application?

My speakers are German physiks hrs-130's. They're omnidirectional, but what is important here is they a sealed design that is extremely precise and fast, but its not enough SPL for synthetic music. The lesser rel's arnt as fast as it, so I ask for something equivalent to the s series. I only want one, and my room is 30m^2. I will be using the full Dirac calibration of the shd to integrate it, so subs with on-board dsp is completely irrelevant, and I'd rather not spend on a feature that's useless to me. What other options are available here? 

endymion_joshi-godrez

Dynaudio, Focal, Sonus Faber, B&W, DALI are all Euro’s who make quality speakers and subs.  

Your confusing a -6dB sub-bass speaker with a subwoofer. Nothing wrong with that just be aware.

Californian Silicon Valley technology sold to a German company.

https://www.velodyneacoustics.com/en/

I can’t say if these folks are actually producing the DD Plus or their simply new old stock. I’ve been using these technology advances since 1983 and two DD Plus since 2011 without a problem. I see their price has gone up substantially for American purchase but your getting remote controlled, six customizable presets and total Auto EQ. The Swiss Army knife of subwoofers.

I’m not a fan of total system DSP so another model in there line up may be more appropriate and less expensive to your needs. Good luck with your search.

Did someone seriously just get upset at me because I didn't consider that a product exists in a regoin because it has existed at one point on the used market? That is spectacular.

As biamping, no tower no matter the size is going to give you the bass authority that a sub will carrying the frequencies below 60hz. At least one that is a technically capable. It has absolutely nothing to do with power.

Velodyne looks like to be one of the only other options in Europe that makes something like the s series. All other subs of this peice range are enormous, and are completely inappropriate for my needs. Thank you. (PS John Hunter himself calls the subwoofers, all the technicians I’ve talked to called rels subwoofers and the marketing on their website called their products subs. The company itself disagrees with that distinction). My only concern is 1. Nemo propaganda, who is someone I trust for subwoofer recommendations, had a horrible experience with their entry level model. It wasn’t broken, it was just terribly braced and designed. 2 A lot of music/HT subs still play like HT subs, which is a presentation I dont like. They exaggerate bass. JL audio, SVS, and the mass majority of subs do this. Rel and rythmik do not. If you have experience one of the sub brands from both sides, could you inform me what side velodynes usally sit on?