New speakers for a new start?

You have a big room. You need a big room speaker. Most of the recommendations here are for medium sized rooms at best, or way over your #5K limit.  I would definitely check out the new SVS Ultra evolution Pinnacles. With 4-8" woofers (2 high front and rear 2 low, front and rear) per cabinet, bass extension, dynamic range, 'speed' and control are assured. The d'Appolito mid-tweet-mid helps control vertical dispersion, a big help in large, high-ceiling rooms that helps soundstage and imaging. And nobody does value better than SVS - at $5000 per pair new, they are one of the great deals in audio.

I would also check around and see if you can find a pair of JBL 4349. These are not your father's shrieking, boomy JBLs. These are superbly executed, very high performance loudspeakers of exceptional sound and build quality. New, at $8250/pr, they are beyond you budget, but if you can locate a good used pair, you might be able to pull them into your range.  At 91+dB sensitivity, the also need about half the power of most of their competition, but can handle just about any amp you're likely to try. The single 12" woofer has slam. Kick drum and bass are easily among the most accurately rendered I've heard in pitch definition and dynamics. The unique 2-way horn/tweeter has a nominal 90X40 degree pattern, again, helping control unwanted room reflections, and it simply doesn't ever honk or shriek. It's just there - clear and dynamic.

The Linkwitz LX521s came up in dipole speakers discussions and they look really, really good, but €27000 is far more than in willing to spend at this point. The kit option is interesting, but the lower price is misleading since no electronics are included so, unless you purchase the Linkwitz dedicated electronics, you'll never get the system or sound that Linkwitz intended. 

Madisound sells the Linkwitz "enclosures" in kdk form for not much money, so that you could theoretically put together a similarly functional system with a dbx DSP unit and a couple of Crown XLSs for oomph. Which, by the way, are NCore-based just like the Linkwitz if I'm not mistaken.

I don't know, kits are by and large the surest way to lose money, at least in the short term. But if I were to allow myself to spend $30K on a pair of speakers right now, I would definitely look at these.

I recently bought the ceramic mini monitors and the BMR monitors from https://philharmonicaudio.com I prefer the minis even though they don’t go as low on bass as the BMR because of the smooth wide distribution of the ceramic tweeter. Both are well made and a great value for the money.

Steve Huff raves about the OGY from https://www.closeracoustics.com/post/introducing-ogy-our-first-bookshelf-loudspeaker

https://youtu.be/G_xSbQylt50?si=54LFO5qRJ13kzbjA

PS audio also has a new monitor https://youtu.be/lVM8oynxy4s?si=1gUnR7jWLAd1bviy

Vandersteen are great too, especially if you love bass.

The Dutch & Dutch 8cs have impressive specs, especially for their size. I mean, 30 Hz at -1.5 dB in a bookshelf speaker?

They get rare praise from both ASR and Erin’s Corner, who usually don't like anything. Tons of other rave reviews too.

And they look good, if you fork over the extra $2000 over the Pro version, which has identical specs but looks like a $119 Monoprice speaker.

One more exhibit in the case that active crossover + DSP dedicated electronics rule.

I may go audition them.

all pf these speakers sound very different with different components attached.