This Might Not Exist, Any reasonably priced, smaller speakers with 100db Sensitivity?

Quality sensitive speaker at a low price = Tekton.  

Polycell 15 is 103 dB.

Perfect SET is 98 dB (there are two versions)  It should be fine and I have a friend whose pair sounds great.

I have successfully driven Encores (96dB) with a 2 wpc Decware EL84UFO.

Some people don't like the looks.  Also some jump to conclusions that these speakers ahe a huge array of tweeters.  They have one tweeter.  An array of the same small drivers is also used as a midrange.

Jerry

Thanks Jerry, real life experience of what truly works is valuable. I say that because a friend of mine tried 4.5 wpc into a speaker rated at 98db sensitivity and it couldn't drive it at more than a very polite conversation level, max. It too 15wpc for it to work well. 

You will need to find speakers that are not only efficient, but also easy to drive.  This means a true 8 ohm, or higher, impedance speaker.  Tekton speakers mentioned above might work and they sound pretty good to me.  Zu is also quite efficient, but don’t suit my taste—they are too harsh and brittle sounding to me.

Although they are not extremely efficient, Audio Note speakers are easy loads and work very well with low-powered tube amps.  They are meant for placement near room corners, which boosts their practical efficiency—they sound much louder than their efficiency rating would suggest.  The AN-E model might actually have too much bass for a room your size, but it is more efficient than the smaller AN-J model  which is meant for a smaller room.

Hoffman’s Iron Law of speaker design says that you can’t have a small cabinet, high sensitivity, and extended bass response. But you can have two of the three.

If you choose high sensitivity and small size, you would want to augment the speaker with a sub, or live without extended bass. In the small room, room gain will be working to your advantage though.

https://en.wikipedia.org/wiki/Josef_Anton_Hofmann

@nightfall the Tektons are very tube amp friendly.  that said, 4 wpc should be plenty for any 98 dB speaker.  something wasn't right.  I am currently sitting here listening to my 4 wpc tube amp (AD1 output tubes) driving my 98dB Horning speakers.  I'm about 1/3 volume, I hardly ever get above 1/2 full volume, and before I get to 1/2 full volume it becomes very hard to talk over the music.  

Jerry