I'm pretty new to audiophile equipment but I was hoping to improve what I have. My lack of experience with different equipment or with comparisons to other set ups is preventing me from making an intelligent decision with what to upgrade. Any insights would be appreciated.

My current setup is this:

[Stereo] Foobar2000 -> dlna -> Musiccast -> Yamaha RX-V683 -> RP-5000f & SPL-120

I use this set up for music about 75% of the time and movies the other 25% so i don't see a solution that doesn't include an AVR though I am open to suggestions. Things I listen for are imaging, separation, bass response. There are times when I am blown away by the system I have but, of course, I am curious about how much better it could be. How much am I missing by using an AVR? I was considering upgrading the speakers the 8000fs but was unsure if that would be much of an upgrade. I have a NUC that I could repurpose as my source but I was unsure how much benefit over dlna that would be.

Is there anything in this chain that stands out as a bottle neck or weak link that would substantially improve sound quality if it was to be upgraded? I've spent a lot of time moving the speakers around and messing with settings and I believe there isn't much more I can reasonably do on that front.

Thank you!