Speakers on the long wall

I suspect you need to absorb/prevent reflection from the windows directly behind you. The timing of direct and reflected sounds is close/not good when you sit in front of a wall.

Heavy thick draperies with a lot of ’extra fullness’, meaning lots of folds of fabric even when drawn closed behind you.

You could make a run of fabric wider than the windows, i.e. the entire length of the wall as an acoustic treatment.

You could rig up a big canvas drop cloth or two as a trial.

Heavy fabric vertical blinds can work, sections with individual controls rather than one long run, and they can be tilted to allow daylight diagonally, while still blocking sound waves

@lanx0003 , GREAT advice regarding what to do about the closer-than-we'd-like back wall (the wall behind the listener).

A couple of other thoughts come to mind:

First, the front wall's reflections will also probably be arriving earlier than we'd want.  This can reduce the soundstage depth.  Diffusion would be my first choice (I don't like to suck the highs out of the reflections any more than necessary), with absorption as a last resort. 

@scooterbug, yu can use a mirror to find exactly where the front wall treatment needs to go. With the mirror up against the wall, positioned where you can see the reflection of the front edge of the speakers from the sweet spot, that's the area to target.

The speakers are probably getting less boundary reinforcement than they were so the lower end of the spectrum will be weaker, and that might account for the "hollowness".  You may have to juggle a trade-off between bass quality and spatial quality.

The good news is, you have nice long sidewall reflection paths.  So I think you can get pretty good spatial quality if you can address the first back-wall and front-wall reflection zones.

I would adjust them until they sound good, good to you that is. They will sound different then previously but that does not have to be a bad thing, 

Remember this is just as traumatizing for your speakers as it is for you so treat them gently and with patience, and don't force the issue. 

I’d leave the speakers 6’ apart and pull them out until the fronts are 3’ out from the wall and I suspect things will open up and you’ll experience better soundstage depth (you can experiment pulling them out further as well).  Are you currently 9’-10’ from the fronts of the speakers or the opposite wall?

Yes, the listening position is 9-10’ from the front of the speakers.

Thanks to all for the suggestions.  This provides me with options I haven’t considered before.  I really want this to work again and it sounds like it can be accomplished without too much disruption, and words from the other half, who really doesn’t care 😥