Tony,
These are all great questions.
Yes, in fact, I've got NoRez anywhere you can stick it!
I did in fact do the underside of the top, and the very bottom portions of the enclosure.
In the photo I posted, I hadn't finished putting all the NoRez in the enclosure because I hadn't done the holes in the top for the hookup wire to the open baffle MTM section. We clamp a backing block to the underside of the top to prevent blowout of the MDF as the drill exits through the bottom of the hole.
read somewhere that the inductors should be spaced apart by a few inches... which doesn't seem like a possibility if its mounted internally. I see that on Bill's external box he put them at different angles -some on the flat, some on the side, others on the side but rotated to a different axis, etc... How big of a deal is the spacing and orientation?
Great question. Yes it is very important how you arrange the inductors. Otherwise you cause cross inductance, and the values of the inductors changes. Basically, (IIRC) the hole through the middle of the inductor is like a pole, you don't want the poles to be in line with each other (like 2 doughnuts on a single pole). You want the poles arranged as far apart(physically) and with the poles arranged at far apart magnetically(?) as possible. So in practical terms, the best way is usually to lay the bigger inductor flat, and the other one up, as if it's going to roll away from the flat (bigger) inductor. This way, the poles are not inline, nor parallel, but at perpendicular to each other. This will minimize the cross inductance in the tight physical constaints usually found in internal speaker crossovers.
The devil is in the details.
As far as internal vs external. That's a personal judgement call. In theory, not having the components in a box that's being pummeled by soundwaves and vibrations is a good thing. Also not infringing on the air flow and box volumes is a good thing.
Cheers
