Efficient Floorstander

Zu's are nice speakers. I would recommend speakers that have adjustable bass like the Zu Def mk4's. If you move into a smaller room you can adjust the bass so it does not over power the room. Or if you like the speakers you already have just add a quality sub or 2 with adjustable gain/eq.

Either way adjustable bass will make changing rooms much less painful.

I second Dodgealum and Daedalus, I understand about your price limits. We both answer threads regularly and recommend Daedalus. They are simply great speakers and my DA-RMAs are staying for good.

I changed from Acoustic Zen Adagios and I can recommend them too. Well finished, with a benign impedence and reasonable sensitivity, I think 89db if I remember rightly. I thought them very good for the price and was able to drive them with a 20 watt SET, so they should be OK with the Audiomatt, though you can never be sure, unless you try them in your room.

You still might look out for second hand Daedalus, or Lou at the company may know someone wanting to sell, to upgrade. They don't come up for sale often second hand, people don't sell them

In order to work well in both small rooms and big rooms, here are some of the things that imo help:

1. A well-controlled, uniform radiation pattern. The well-controlled part allows you to aim the pattern to avoid early sidewall reflections (which helps the room seem bigger than it really is); and the uniform part because whatever role the reverberant energy ends up playing, we want it to support (rather than detract from) good timbre. Imo the reverberant field is more important than the first-arrival sound in most rooms, and I can explain why if you'd like.

2. A fairly high degree of adjustability in the bass region. The kind of bass tuning that works well in a large room with modest boundary reinforcement can be overwhelming in a small room with strong boundary reinforcement. The port location is less important than how the box is positioned and tuned; Audio Note speakers, for instance, are rear-ported and tuned to go in the corners. Imo there are valid arguments for rear porting that are especially applicable to small rooms, assuming it's done right.

3. Some adjustability in the high treble region. Short wavelengths are the most easily absorbed, and the amount of absorption varies quite a bit from one room to another, so it's nice to be able to dial that in a bit.

4. You already have efficiency on your list, but I wanted to add that good efficiency generally helps at both ends of the loudness spectrum: You tend to get better liveliness at low levels (useful in a small room), and you can enjoy the crescendos in a big room. In all rooms, high efficiency (and/or, to a lesser extent, high thermal power handling) correlates well with good dynamic contrast, and dynamic contrast is used by musicians to convey emotion.

Nice amp, by the way.

Duke
dealer/manufacturer/yes I got a dog in the fight

I second Duke's comments as a happy owner of a pair of Audiokinesis Prismas. My room is 15'w 12'd with 8' ceiling. I sit 8' from the front plane of the speakers. The toe-in built into the cabinets gives a wide sweet spot and minimizes side wall reflections. I have a bass hump due to increased loading on the left side of the room. The dual rear porting allowed me to smooth room bass response. The speakers are supplied with different length port tubes. My JAS array tube amp drives them with lots of relaxed power.

Duke's speakers would work nicely in your room, I would recommend you consider the Rhythm Prisms as they are the smallest floor stander he offers. I have been using his Jazz Modules for several years now in a variety of rooms, one of which was much smaller than yours. Their flexibility with placement is a bonus. Duke himself was pretty surprised at how I had mine set up in a very small room and how good they sounded.

That being said I do not know what your budget is, but Duke has a introduced newer version of the Jazz Modules. They are larger and About twice the price of the Rhythm Prisms but IMO these speakers have proven to me to be far and away better than anything else I have heard in my system, including the Audio Note ANe's which are substantially more in cost.