*DAC

@navyachts , I understand your position and wanting to stick with a speaker based solution.

While I’ve not heard it, the original Denafrips Terminator or Terminator 2 might be worth researching. It’s still R2R like your Gustard, but most of what I read on the Terminator is that they are highly resolute with a lot of detail. It may be the ticket at around $5k new. 
 

At the “how much more” over $5k level, and if you can stomach the appearance and goofy UI, you might want to look into the Chord Dave. Do you own an audio cabinet with doors that close? 😀

@yakbob LOL +1 on the Dave design. I just can't bring myself to spending over $8K on a DAC when they say it benefits by spending a further $5K on their M Scaler! The Terminator sounds interesting thought. Thanks!

"I just wondered if there is a way to elaborate on those background sounds (details) a bit more."

Yes, speaker placement (including toe-in).

Perhaps just slight/minor repositioning if the ESL's are already sounding close to what you want.

I assume from the room pics that you don't want to "treat" it.

DeKay

@dekay well, by looking at the room, it is difficult to treat. We made heavy curtains to cover the windows and I did buy five 2‘ x 4‘ acoustic panels from GIK acoustics and place them around the room wherever I could find some bare wall space. as far as speaker placement, I have used the flashlight method as outlined in the Martin Logan set up manual. I could try tweaking them a little bit more I guess. I will try. Thank you!

I didn’t see the acoustic panels, but recall you posting about the proximity to sofa (left speaker) and the large window some time ago.

I haven’t worked with panel speakers for years, but once you get the soundstage to be more specific/defined it can usually be fine-tuned further.

The same goes for traditional box speakers.

I would start with tiny changes in toe-in for your intended goal (maybe start by toeing-out).

PS: Our living room is a non-symmetrical "U" shape with no commercial acoustic treatment, but I’ve achieved excellent sound with a few setups over the years.

DeKay