Cheap tweak from Virtual Dynamics:

Having been around audio for a long time and a past filled with car racing and engine building, when I say tighten with all my might I should have clarified the situation. Torx can be set up to fit two screwdriver handles or a ratchet drive. For something like a woofer I deliberately used the small handle Torx that limits leverage.

I don't know the exact amount I'm able to exert with the small drive, but it's like tightening brass parts on a carb when assembling an engine, you don't want to overdrive it and ruin the whole assembly.

I believe Dali must have used a locking compound on the screws, keeping the torque uniform over time. I have no proof but this behaves that way in my opinion.

No question that the ratchet handle and reverse motion could break the bond if a driver needed replacing, but I think they have it right where they want it and it was planned that way during assembly.

Albert,
You would make a great candidate to do the brass for steel swap out. Lotsa drivers lotsa steel. I performed that surgery on my Dunlavy 4's some years back. I used brass machine screws intead of wood screws. The machine screws had a higher number of threads and they extended all the way to the head unlike the wood screws. Made for a more tuneful sound that was also less noisey. Tom

Interesting thought, I don't doubt you. All materials have a sound and brass is definitely more friendly than steel.

Maybe I should contact the tech guys in Denmark for advise, the same ones I spoke with when I redesigned the crossover.

"I love cheap tweaks that have potential to improve sound."
Have you heard of EnABL?

Can't beat $26.00

Cdc,
Very interesting. I remember a fellow writing in Audio Amateur some years back about gluing felt strips on the face of a cone driver with the idea of breaking up standing waves and how well he thought that worked. If I decide to EnABL my drivers I will use the AVM acoustic paint instead of the paint sold in the kit. Tom