GM's MLTL with 416-8B

[westend9]

If you cut a dado in the middle of the panel, you have just reduced the stiffness of that panel. A better way to attach the brace is to use pocket screws and glue. Also, much easier than cutting a dado.

There are adherents to different methods, and lacking the testing required to assess the merits of different joinery, I'm going with what I know works best for me. The underlying question of the structural integrity of these two methods would be: Does using fasteners and not creating a 1/8" dado have more structural integrity than cutting the dado and insetting the brace into the panel? I'm thinking there isn't much difference.

Yeah, for pipe designs there ideally should be no horizontal cuts or wide joints since the majority of the pressure waves are vertical and no sense in adding any more HF 'hot spots' than necessary, so as I previously noted, vertical boards boned on edge and maybe a screw or two (or air staple if one has the luxury) to hold it in place while it sets with tie boards to bind them together horizontally and one running the full vertical length to tie together all of them plus provide some driver support/mass loading. That, or use a vertical 'X' frame to 'kill all the birds with one stone'. One example: http://homepage.mac.com/tlinespeaker...aps-211010.pdf

I always did the former to use up scrap or used stock found at work sites or at the curb. I built a lot of cabs that had braces made from scrapped concrete former boards.

At one point I wound up with many hardwood closet rod, so made 'X' braces by tying them together with safety nut wiring with some PL400 as a bit of extra security because I had the appropriate tool. Today, I wonder if inexpensive tie wraps/PL400 or similar might not work just as well.

Anyway, I didn't own a router until some years after my peak building 'career' and frankly have only played a bit with the two given me, so while I can marvel at what some folks can do with them, it's just too much extra time for too little real benefit at the casual DIY level for me to bother if I ever get the chance to resume speaker building when butt joints and the occasional glue/screw block clamped with two or four picture framing clamps suffice. I shake my head in wonder when I see a complicated superstructure of varying size clamps to hold a simple rectangular cab together. I am big on diying jigs from scrap to streamline construction though, so I guess to each his own.

GM

Thanks for your reply about the bracing, GM. I believe we are on the same page as to the bracing and general construction techniques. Initially, I was going to build the bracing very close to the linked Pensil 12 cabinet. I changed my thoughts about that when considering the benefit and material use of the side to center brace window pane, combined with the obstruction they would cause to the pipe effect.
Instead, I am using two horizontal members joined to each side brace to tie to the center brace. It is, in some ways, more work, but I'm only doing this build once so I can rationalize the extra joinery required.

I'm fairly new to using a router but the ease of some operations make it a have-to-have tool for me now. It is like the advent of the battery powered screw guns, the epiphany being, "how did I get along without this sucker?"
I am just about done with the bracing, only needing to machine the center brace and ease some edges. Standby for pictures of a myriad of clamps.