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 
