The 927-8A are at home now.
I took some more pictures.


Some measurements :
overall diameter : 40,64 cm (16")
depth when front mounted : 145 mm
mounting plate : 210 mm large and 65 mm hight

I have made a "quick and dirty" A/B comparison with my 2234h in a JBL 4320 enclosure ( crossed at 1200hz ).
Of course this is purely subjective and this system is not optimized for the 927-8A.

"As is" the speaker with the 2234H is more coherent and the transition between low and mid frequencies are smoother. I think the 2234h can be crossed higher then the Altec. It seems to be a little faster as well. There is a small difference in sensitivity in favor of the Jbl (+- 1 db ) but it might be because the Altec is 10 ohms.
But for the low frequencies ( 30-400hz ) the 927-8A is the winner.
Drums and contrabass sounds more real. The impact and the authority in the bass is better.
I think that with an optimized enclosure and crossover the Altec's have a real potential.
I will seriously consider using these A927-8a for my DIY project ( 2 way in a 160l enclosure )

I'll be on holiday for 3 weeks so i'll start to really work on this project in last september.