Don't put them against the wall. The manual even advises against this. You'll see Tannoy speakers in wacky locations (like right up against the wall) in ad/product photos, but that's silly. Your listed distances sound like a reasonable starting point, though with a 14' front wall you'll observe that the bulk of the speakers themselves will start cutting into your optimal spacing. It's still quite workable, though. You were wise to scale back from the Westminster in this case!
I like a nice midfield triangle myself (6.5-7' x 8-9' x 8-9'), with a healthy dose of toe-in -- close, but not *quite* directly pointed at the ears, and certainly not crossing over in front of me (a very questionable manual recommendation there).
The tweeter height is an issue with the Canterbury SE. Get pedestal stands or pucks to tilt them up. Perhaps the GR has more treble energy to allow for the right amount of off-axis energy, but then that would become dependent on seating distance -- so hopefully the GR also sounds best with tweeters and ears level, and it remains up to us to achieve that.
I like a nice midfield triangle myself (6.5-7' x 8-9' x 8-9'), with a healthy dose of toe-in -- close, but not *quite* directly pointed at the ears, and certainly not crossing over in front of me (a very questionable manual recommendation there).
The tweeter height is an issue with the Canterbury SE. Get pedestal stands or pucks to tilt them up. Perhaps the GR has more treble energy to allow for the right amount of off-axis energy, but then that would become dependent on seating distance -- so hopefully the GR also sounds best with tweeters and ears level, and it remains up to us to achieve that.