I am sorry but I still don't get it, wouldn't the tweeter still be center aligned to the woofer if you flipped a horizontal speaker vertical or a vertical speaker horizontal?
Yes, the tweeter would remain center aligned as you suggest, but it's dispersion pattern is dependent on orientation. Notice in the pic the ribbon runs vertically- that would be the ideal orientation, thus providing better side to side dispersion, with more limited vertical dispersion. Accordingly, this speaker requires horizontal placement for best ribbon dispersion. Rotating this cabinet vertically would collapse the tweeter's side to side dispersion as frequency rises. The LT-10 may be specified for horizontal or vertical orientation, the change being the ribbon alignment.
I understood that the baffle board the AMT is mounted on unscrews and rotates to accommodate horizontal - vertical alignment. This would position the AMT to the side of the woofer for vertical alignment but the left and right could be mirror imaged; not so bad.
So Peter, you're saying you can custom order the AMT mounted on the same axis as the woofer cone for vertical alignment? If this is the case, what happens to the port placement; two smaller ports?
Jeff you might want to take a look at these: http://www.adam-audio.com/en/installation/products
The GTC 55 is about the same size as the LT-8 and has an AMT tweeter. The GTC 88 is very similar to the LT-10 in spec'd SPL and sensitivity. Of course you don't get Roger Questeds pedigree but the components appear to be of similar quality. The AMT units in the all GTC's can be reconfigured for vertical or horizontal placement.
Thanks Peter, very cool...
I see the benefit of time alignment, maybe not so much for absolute alignment to the woofer cone. As you pointed out the LT-20 sort of shoots a hole in the idea and maybe that's why the LT-18 gets a leg up. It's really great that Roger is so responsive to customizing the boxes.
My experience with AMT's have been mostly dipole arrangements which present a different sort of problem.
For me the the mention of an AMT driver brings to mind the ESS marketing phrase "Sound as clear as light"; an elegant and ubiquitous statement as to what an AMT driver can do for the enjoyment of audio. I hope someday to have the good fortune to see one of your projects with the Quested units. Thanks for the info Peter and keep posting your progress.
Peter, would the one you speak of above be in addition to the LT24?
Also Peter, I believe the LT10 is using a Volt woofer; do you know, is it using a Beyma AMT unit?