Optimize Stereo Experience - NYC Studio


Hey, happy new year to all - new to this board but been lurking for a couple of years now.

Needed some help with this 2.1 stereo system I've assembled in my small NYC studio apartment: NAD T 758 + pair of KEF R900. I use Amazon HD and Spotify to stream the music. Below pic shows that my room layout doesn't allow for placing the two speakers in a straight line (have tried all other room configurations, unfortunately this cannot change). I have so far 'corrected' this via DIRAC and sounds significantly better with it. Had the following few questions in case anyone case help.

- Any further additions to the system hardware to make the sound improve significantly (amps, wires, speakers etc)

- Would a center channel speaker make sense. I mostly listen to music but sometimes do watch TV/Music too. I have a feeling the dialogue can be improved if I add a center channel.

- While I tried to test A/B Spotify vs Amazon HD and couldn't hear a very drastic difference, would love to have people's opinion here. I would definitely prefer Amazon HD over Spotify, but the crappy UI of the Amazon in BlueOs (NAD) makes life much easier when browsing for new music on Spotify.

- While I can't change where I live, any other tips / suggestions re speaker placement?

https://ibb.co/dmRD1Ph
128x128kmalhotra
Check out this video you’ll get the ability to have more bass in your music and be more neighbor friendly. This product will allow you to actually play the music a little louder without bothering your neighbors.
Pull the speakers out as has been suggested. Set your AVR to flat response and then play with speaker position for best sound stage and bass response. Add room correction if you must but it usually just messes things up (not a big fan of it unless done manually with full control). 
Maybe have a critical listening position and a non critical listening position.  Optimize each one. You can get sliders to slide them back and forth with no damage to anything. You could pull them out when critical listening and put them back when not.
Thanks - this looks pretty solid (the podium) but too clunky for my small space unfortunately. 

I'll try the roon + tidal combo to see if there's any improvement in SQ for the same tracks.