Speakers for a unique small room

OP,

A good headphone amp and set of headphones can be really satisfying. Perhaps not forever and only. But for your situation. Perfect to dive in and put together a great little system.

I developed mine over about 15 years. You can see mine under my UserID. Typically I listen to it every day for a hour.

First I would like to recommend Woo amps. I have three. I started with a WA6. Then a WA6SE and finally a WA5. The latter I got because I really wanted to experience a 300B amp. Honestly, this system sounded so good that I found my main system really lacking in warmth and musicality. I caused me to upgrade my whole main system (the most important part being the ARC DAC and ARC amp). 
 

The Woo WA5 with top level 300B tubes is simply stunning…. Detailed, real and musical with incredible power to drive any headphones (and speakers if you want). Assuming you do not want to spend that much money.. if you choose efficient headphones like good quality Focals you can have and incredible system. 
 

Personally, from my experience, beware of solid state headphone amps… with the speakers so close to your ears hardness and fatigue comes with inexpensive / SS headphone amps. I have owned many. 
 

My favorite headphones are the Sennheiser 800s… but they required the power of the Woo WA5 to take control of them and feed them a very warm musical signal… otherwise they could be a bit trebly.

Reference 3A MM de Capo BE 🥇🏆🙌

When did a 10' x 14' unsealed space become rated as small for use with small speakers only? I think the 1/3 rule for speaker placement would work, Cardas is practically identical in this room size, or at least it is a excellent starting point. noaudiophile has following for a 10'x14' room, if you flipped sides of the room(main wall to right of door) the staircase might actually work to your advantage. As far as convenience that would be up to the OP but should sound better.

I have a similarly sized room, though with some different challenges. the width is closer to 9.5 feet and the length is closer to 19 ft but with a bay window behind it. I also have (and love) that SVS micro. Mine seems to work best along the side wall. 

My best experiences have been with sealed and front ported speakers. I had the LS50s in there for a long time, but never quite got them to work. When I moved them to the basement and the main TV room where they had a lot more room, I started to understand why people like them so much. 

The two best fits for my room came in under what I had set as a budget - the Sonus Faber Lumina II and the Falcon Acoustics Mofi branded LS#3/5a (the sliver badge, I believe). Both sound fantastic. I got the Falcons used with very low hours, and they did take a while to break in. Both work incredibly well with the SVS sub. They also seem less sensitive to distance from the side wall. I basically have them 2.5 feet out from the front wall and the center point on the tweeters right around 6.5 feet apart toed in to a point just behind the listening position which is just under 7 feet away. It’s pretty close to an equilateral triangle. 

Rear ported speakers (or speakers with a passive driver in the rear) struggled even when the port was dampened. 

It is a totally different beast (or sound), and I know that you explicitly mentioned ‘no Klipsh’, but they play really well placed towards corners. I have Heresy IVs that I swap in on occasion when I want something more lively. The Falcons and SFs share almost none of the same sonic characteristics - my sense is that they will be more to your liking. 

Playing around with acoustics in a small room is an adventure, but you can certainly find great sound. Best of luck.