Is my ceiling too low?

Hi, I am going to move to a new house with a 15'3"x12'x7'8" (LxWxH) room in the basement as my future dedicated listening room. Is the ceiling too low? I am listening to a pair of Harbeth HL5 with Naims.
I am a little bit upset because I had a chance to ask the builder to make the basement ceiling higher such as 9' but I didn't because I thought the ceiling would be 8ft, which I think it's ok, until recently I double checked my blue print: it's 7'9" minus the ceiling and berber carpet, not 8ft...and it's too late the change it now...

Please give me some opions, thanks!