I've been slackin off, but now all the parts are now cut to size and mitered, ready to glue. The homemade cross cut sled was a bit cloogey, but it worked OK.
The midrange/tweeter baffle is made of 18 x 1.5 pieces laminated together so that the plys are perpendicular to the vibration force, and those are made, ready for routing the driver holes.
I ordered a roll of
rubber asphalt roofing membrane as a damper to glue inside the plywood. It is extremely thick and heavy and will damp vibrations well. It is by far the cheapest damping material out there. But it has to get trucked in here from the distributor's warehouse in Charlotte, and I'm not sure how long that will take. Whenever the next inter-warehouse transfer occurs. I am not paying for the shipping, so I can't complain. It is 105 pounds per oversized roll, so shipping by means is not an option. I am tempted to proceed without it, but from past experience I know I will regret not damping the panels. Meantime I will route the driver holes. Then I can do the crossovers until the damping arrives.
I read about asphalt (bitumen) pad as panel damper on the speaker designer's website, and could only find audiophile parts sources of it which were too expensive for the amount I need, and likely stink like petroleum. I looked at the damping sheets available for car audio, dynamat and such. All are too thin, too low mass and way too expensive. I went to HD and smelled the tar products they had there. The products made by GAF who makes my stuff did not smell, but the other brands did. So we'll see when it arrives.
The idea is to brace the panels so the minimum unbraced span is small. Then the minimum frequency is high, which is easily damped. The asphalt is huge internal friction and high mass, so it's a good damper.
Pictures coming.