A butt-load spent in cables - how much improvemt?

Great setup. Those alcoves for the speakers/sub might pose some significant bass management issues have you considered adding bass traps in the corners at the back of the alcoves?

I see the fronts of your speakers are brought forward from the edge of the wall- so edge diffraction should not be so much of an issue...nevertheless you might get a better imaging withe the speakers forward a bit more.

Strictly speaking you should close the gap between the frame and the center channel (make sure no gap) - a picture frame sometimes works well - a gap will give you edge diffraction issues and reduce the imaging.

I really like this room and setup...it looks awesome and that 71" screen has me drooling!! I hope my suggestions are taken in the spirit they are offered...just passing on some experiences...suggestions only and no criticism intended on what is one of the more impressive HT setups on A'gon. nice job.

The "how-much-improvement" depends---Lots of money and lots of exuberance/expatiation can make us happy; unfortunatly it seems to never end. I was reading an ad for 6ft. biwire at 17k. Then I think for those cables one should have near that amount in speakers--that amount in amplification--that amount in the front end,be it analog or digital.---Oh ya, ics to match. I think the parts need to be of similar quality to match the cost of wires. Meaning I think good wires improve good parts;but I think the "good parts" come first.---upgrading each as part of the journey.---I find I need a "fix" every 6months to a year, as I go along. Wires for me are last in the chain of money spent.I don't have a problem with those whom think differently.

The results of every double-blind cabling test ever performed speak for themselves. The reluctance of proponents/salesmen of expensive cabling to engage in such testing speaks volumes.

Bring your speakers out more. You have the space. I'm certain they can match the room acoustics much better if you experiment a little.
Also, this is a VERY inexpensive tweak.
As to cables, my feeling is Home Depot extentsion cord can sound as good as $1000 speaker cables. I have experienced it myself. Sometimes the expensive stuff merely sounds different, not better. There was a A/B comparison done by Absolute Sound a fre years ago and HD extension cord was near the top with multi-thousand cables. No kidding.
Please do compare and post your results.
Good Luck.

You never need apologize for conducting your own back-to-back tests of what works best for you. If you put the old cables back and are pleased with the results, you can re-sell your expensive cables and save a bunch of money. If you find the expensive ones sound better, you can give yourself some peace that your money was well-spent.

While hardly unique to high-end audio, we can apply enormous psychological pressure to ourselves to conform to others' expectations. Heaven forbid that we not be sophisticated enough as trained listeners to not hear "obvious" differences! People we don't know might whisper behind our backs about our being country bumpkins or such.

It is very difficult for us to separate advertising hype, fads and fashions from what we really hear. However, I wish more people would do what you've proposed. Haul out the old stuff and do a reality check - compare it to the new. Then choose the one that makes sense to you.

Note that none of this requires you denigrate the one you don't pick. You are not writing your thesis for your PhD, nor are you declaring what is good and noble for the world at large. You're simply choosing some wire for your stereo.