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!
hififish
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Thank you so much for all the helps! Now I know there are still many things that I can do to get a great sound in this low-ceiling room. I think the first thing I would do is to ask my builder where the duct will be in this room and how wide and deep it is. Now I have another question, if you have a choice, where do you want to have the duct in a room like mine, close to your speakers or close to your chair? Thanks!
Add some diffusion on your ceiling. Auralex makes some excellent diffusors. I have a similar basement ceiling problem. As Viridian noted above find the first reflection points and use a combo of diffusion and absorption panels. This can really make a differnece and overcome some if not most low ceiling problems. Look at my system for some ideas if you want. In most cases you wouldn't have to go to the extreme coverage like I did, but I have a dedicated room, and I please myself, this arrangement sounded best.
7'9 is still pretty tall, actually insanely tall for a basement. I think you'll be fine.