How to tame brightness

I agree with attacking the acoustics first since this is where a smart 'file begins the quest to get great (best) sound. If you can take the brightest sounding system/room and turn it into a dull mush by overdoing sound treatment, then your happy medium obviously lies somewhere in between. If you have slap echo, you're gong to have bright sound. Start with the 1st reflections then the room tri-corners where slap echo lives.

While I agree that felt is a good thing because diffraction sucks, diffractions usually affect imaging more than anything else.

the Epos tend to get sharp/edgy/hazy/shrill

This is a characteristic with Epos. Been through this with B&W. While I tried all reasonable solutions (including covering all the walls with blankets), in the end I found no good solution in adding one error to compensate for another. It was a bitter pill but had to dissolve the entire system.

If you must keep the speakers, Creek CDP and amps are voiced well for Epos, all being from Mike Creek's company, and this is the best I heard from Epos.

Other option is to buy an equalizer.

Please don’t flame me, my first post. I actually was trying to find another post about a guy with B&W 700 series speakers tweeters being too bright. A LOT of guys were trashing B&W speakers as a whole towards him. I am in the camp that the aluminum nautilus tweeters can be too bright, BUT find the diamond tweeters AMAZING!! Fleetwood Mac is in my living room!
  As to trashing ALL B&W speakers, why would Abbey Roads Studio use them for years??? Kevlar mids being congested?? Really? Am I a B&W fanboy? Maybe. They were my entry, along with my Macintosh(NOT APPLE prod.) amp into HiFi. I LOVE my smallest made B&W 805 diamond tweeter speakers on stands. I’m in a townhome, cannot have floor mounted speakers with heavy bass, or a sub (neighbors). 
  Anyway, I found it concerning to hear so many negative comments about ALL B&W speakers. I saved A LONG time to afford this equipment. I DO BELIEVE there are better speakers made, I just spent (to my budget) a TON of money on what I have. Sure, $100-200K speakers absolutely SHOULD sound better!! But I’m really happy! So, why all the negative thoughts on B&W? Comparing them to “THE BOSE of HiFi”, in one comment?? That’s PRETTY HARSH! IMO. VERY harsh!
  I could fire back that people thinking sticking speaker cables in a freezer “to improve them” are one shy of a six pack! Or, these “grey stones, or polished river rocks, or WHATEVER they are, placed on your equipment “give a darker, tighter soundstage”. NUTS! And let’s not forget “the green marker” to color the edge of a CD. How many bought one of those markers??
  Who are these people?? I SERIOUSLY need to invent the new audiophile “pet rock”, or something, make gobs of $$, and retire! LOL!
  I LOVE a spirited debate! But I stop at trashing somebody’s HiFi equipment. (rocks and green markers excluded). It’s disrespectful. IMO.☹️
  GLAD to be here!! Hello! To everyone!! Hell, I STILL covet my still working/pristine SONY DEJ-1000 DiskMan CD player! All magnesium construction, no plastic, with an honest to god optical line-out. Pretty cool for a 21+y.o. portable CD player!! Has a neat little charging stand as well. I treasure it from my H.S. days! Surprised it still works, the blue back-lit remote works perfectly as well! Hard to find the gum-stick batteries for it though. Any of you guys have an audio treasure still working?? 
   I have no problem debating this or that. Tubes or solid-state amps, CD vs. LP, you get the idea. But I stop short saying somebody’s equipment is garbage, or, equate their speakers to “HiFi BOSE”, that’s too far. I’m repeating myself.
  Anyway, I do have another question, since this is about speakers. I’m intrigued by single cone, full frequency speakers. Never seen any in person, or heard how they sound. A speaker with just one cone, no woofer, no tweeter. Anyone have a pair of these type speakers?? Love to know how they sound, image, frequency response, etc. The ones I’ve seen are VERY expensive!! High five-almost six figures$$ a pair.  

Thank you! Glad to be here! LOVE my “BOSE HiFi” B&W 805’s!!! And my SONY DEJ-1000!

David, Tallahassee