Nasty slap echo

Yep add natural room furnishings little by little (cushioned furniture, rugs, window coverings, decorative items, etc. to absorb sound until echoing is under control enough for things to sound good.

"How does the room sound? ...Sometimes a little echo can yield very nice ambiance to the music. "

That's an important point! It's always useful to understand your room's acoustics and how they are working, but a "slap echo" may be a good or bad thing depending. I've heard some very lively rooms at dealers not unlike yours with significant "slap echo" sound uniquely engaging and lifelike, even quite holographic (in a good way) as opposed to the opposite, ie dull and lifeless!

Even if you can reduce or change it temporarily and listen as a test first using whatever means available, that would be useful prior to making any permanent changes.

BTW legend has it that the original Three Stooges has slap echo down perfectly in their listening room.

Curly: "A whooba whooba"!
Moe: "Shaddap and listen!" Slap!
Larry: "Leave him alone"!
Moe: Slap!
Curly: Nyuck Nyuck Nyuck!

You get the picture...

Oh jeez, now I gotta go and check my comfy Scan leather swivel/recliner I've been using for years to see if it is mucking up my sound....:-)

"You say that in jest, but if the top of the chair is above your head it does affect what you hear. "

Yes, in jest, and yes it is above my head (when not reclining) and yes can no doubt affect what you hear, leather or otherwise FBOFW, due to proximity to ears.

A cheap easy tweak to experiment with....