Advise for new speakers for my basement exercise room

new member. I would  appreciate your expert advise for new speakers for my basement exercise room 15x25. Hard floor and walls with  4 windows and 9' ceiling. I am using near mint JBL 112s but hi frequency sounds are not realistic. Lows are great.  System is Nak CA7 pre, PA7 Nelson Pass 200w amp, and Sony ES707ESD CD player, AQ and Morrow cables.  Like upbeat music for exercise. Don't have time and do not want to go and audition and comfort level is about 5k or less.  My Mission 770s sound better than the JBLs there, but are needed elsewhere.
Thank you everyone for your advise and time.
My basement speakers are older BIC V-830’s
  absolutely great speakers!

 Bass, mids, and detailed yet non fatuiging treble. 
My workout room speakers are KLH Model 6’s I bought off Craigslist for $75. They sound wonderful paired with my Fisher 800C tube receiver. However as others have said, you need to treat the room to tame it down and stop all the reflections before you can judge.
I also have a large work out room but I mostly ride a stationary bike. If you are mostly stationary when exercising you can go with very near field speakers and possibly a subwoofer. This set up will eliminate most of the reflection issues. 
Mirage Omni 260.....or

Mirage Omni 60 subs optional.

Sound will envelop your room.....

You will be pleasantly surprised!

Just about any speaker will sound like crap in a room like that with all the hard surfaces.

You will have to treat that room. (hint) start with some carpet on the floor, if possible.