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
BTW....@ kmalhotra....welcome to the show that never ends...;)

I appreciate your approach to the minimalist system with the PC....*s*
A center channel definitely helps for dialogue, that is where it lives. I ended up with a Sierra 2 with a Raal there. Controlling the level quickly is a plus, up for video down for surround music.
I live in NYC and here are some thoughts to consider. 
1) I put my speakers much closer to my seat, about 8 feet from the center of my seat to tweeter. The closer you are to the speaker, the potentially less room interaction. 
2) You don’t have to use the wall as your boundary to define a living space. For example, there are interior design ideas where a large area rug to define a living room. The couch, coffee table, media console and speakers are placed within the boundaries set by the rug. I mention this because I don’t think your speakers have to be next to a wall for it to look right.