High end speakers at low volume

Leak 130 and a pair of Wharfedale Heritage Lintons or  Mission 770s. My job here is done LOL

I can’t imagine rock music sounds good at low volume but maybe it can with horns. I suggest giving Rockport speakers an audition. Used Atria might be in your budget. Good luck! 

IME every recording has a “correct” volume where all sounds as it should. I have, over the years, thought about writing the number down on the inner sleeve so I can just dial it up after dropping the needle—no need to figure it out every time I play the recording. Unfortunately, my system has shared the main living space as long as I’ve been married with child so most of my listening is done at levels below the preferred volume. I have found, however, that high efficiency helps. I get more jump factor at low volume than with less efficient designs at the same listening level. It just seems to me that the speakers take less juice to wake them up than with a lower efficiency design. I am talking marginally more alive and real sounding not night and day. For the most part regardless of speaker you really need to turn it up to the “correct” level for each recording.

Many single-driver, high efficiency systems and horn-based systems do excel at low volume liveliness.  But, many have a “peaky” or rough sound, so there are tradeoff you have to work around (meaning you should hear them first).  
 

For example, Zu speakers sound extraordinarily dynamic, with a very sharp attack, but they sound brittle and unpleasant to me after listening for more than a few minutes.  Classic Klipsch speakers are also a bit rough, but only a bit, and they may work.

One of my favorite speakers is the Charney Companion.  It is a single driver, high efficiency system that is smooth and natural sounding with very good dynamics.  It is a little outside of your price range and I would bet it is impossible to audition in Europe.  Charney does have less costly models which I have not heard.

To me, the best bet would be Audio Note speakers.  The are relatively compact and are meant to be place near the corners of the room or a back wall.  These speakers sound full and rich and lively at modest volume levels.

I have similar limitations, though perhaps worse needing to place my speakers hard in corners. Had SF electa amator IIIs in that position for a while, but they were compromised like that. Sounded great, but sound much better now moved to my kitchen system where they can breath. I ultimately chose Charney Maestros which are designed for corner placement. The Maestro X is larger and designed for placement against the front wall. 

I only live a couple hours from Brian Charney and was able to demo the speakers, which had me spec'ing a pair to work with the decor of my room (they are made to order) that week. Also had him build a 300b amp for me, though I switch to a First Watt M2 for the summer. Given the super high sensitivity of the speakers, 8 watts sounds great at low volume, and can play way louder than my ears could take. 

As mentioned above, I am sure they are impossible to audition, but Brian Charney uses Voxativ and AER drivers, and it may be possible to audition their speakers to see if that approach to single driver speakers suites your taste.