I think the Pulsars would be a great speaker for your situation. They are not sterile nor are they overly warm, they probably image and soundstage as well or better than your Ref 3As and will certainly add the bass you're currently lacking. They may even have enough bass if you move to a larger room as well.
The Dyns are great too, but personally I can't get past the looks. Not sure the Avalons would give you the warmth you're looking for but I've not heard them in a while. Best of luck.
How about LSA's LSA2.1 Statement? Price is right, has nice smooth airy tweeter, and reviews indicate it has excellent bass extension. A pair of 6-1/2" woofers per side is about as much woofer action as an 11x14 room could handle, and I have Mirage M5si's, whose dual 6-1/2" woofs have no trouble pressurizing my 18x22 room downinto the high 20s.
It would be a great match for your amp. Talk to Wally; see what he thinks.
I also agree with Phasecorrect: although I suggested the LSA 2.1 Statements, your situation is practically begging for a sub or two. Your current speakers are excellent from around 50 Hz up and your room is not very large. A viable solution is to add a sub or two to fill out that bottom octave. The advantages of powered subs are that some of them have high pass filters that limit the LF signal going to your little monitors, thereby making them clearer and more dynamic in their natural range, you can experiment with the subs' crossover points, phase relationships, and bass output to match your room, and you can locate the subs in-room where you get the best bass response while you place your monitors where you get the best soundstage and imaging.
If you get the first Stereophile test & demonstration CD, it has test tones from 1Khz down to 20 Hz and makes it easier to get flat bass response from the monitors' output down to the lowest capabilities of the sub(s). I find it easier to use this tool to integrate subs with sats than it is to move big heavy full-rangers on an inch at a time one way and another to try to get best imaging, fewest room resonances, *and* best bass linearity and extension.
Right now Audio Advisor has the MartinLogan Depth 3-driver sub on sale for$1349.10 through Sunday. It has a high pass crossover settable to 40 or 70 Hz and low pass to the sub ranging from 30 Hz to 80 Hz. Its bass extends down into the 20s, yet it has its own volume control so you can get your best bass extension without overloading your foom. It features three 8-inch aluminum cone drivers for fast transient response to blend with your Reference
3As while offering the radiating area of a 15-inch driver for bass slam and depth.
If it doesn't work out for you, AA has a 30-day trial-and-return period and all it costs you is return shipping.
Disclaimer: I have no relationship with Audio Advisor except as a satisfied customer. I have no relationship with MartinLogan subwoofers except as an impressed listener.
Proac d28. Warm and yet still open and detailed. Superb speakers. There's a pair of dynaudio focus 340s for sale right now in your price range. I've owned a pair before and they are dream speakers and worth every penny of their $7500 retail price. They are very close to the confidence line IMO. Sonus faber Cremona Ms would also work. How about Usher mini dancer 2s? Also in your price range and superb speakers.
I'd never considered the Ushers nor the ATC's. The more I research the Ushers, the more I'm impressed. Now - the last set of speakers I bought after actually hearing them were my sadly departed Maggie 3.6R's. I'm not in the market for something that big anymore, but I'm not adverse to buying a pair of speakers sound unheard. I'd never heard my de Capo's and love their sound (again, except for their limitations as monitors).
The Proac 28's also sound (in writing) fantastic.
I have this misguided bias against large speaker manufacturers, though - that artificial and unwarranted small-market/boutique favoritism. I'm also hesitant to use multiple components from the same manufacturer for similar superfluous reasons.
Simao, in New Mexico I have a 13 x 10 x 8 listening room. I use the LSA1 Statements close to the corners and have use the LSA Statement amp along with other amps and preamps there.
But there is one thing that made my room a joy. It is the Zilplex eleven cups in this room. I heard Diana Krall move from my too closed in room to the full stage for Live in Paris. Set up your room exactly as shown in their directions.
I would just keep the Reference 3As, but I do know how great the LSA1 Statements sound