Butt joints are easier. Mitered joints look nicer. I'd only use mitered joints if the finish required it.
So butt joints in plywood will seal well enough? I am concerned that the multiple plies will be leaky compared to MDF... I am also concerned that they will not be structurally sound (note that I prefer to not use screws, just glue which has worked fine for me with MDF).Butt joints are easier. Mitered joints look nicer. I'd only use mitered joints if the finish required it.
Lighter and denser?Lastly, it should be noted that quality ply is actually lighter and more dense than traditional MDF.
No screws because I want to leave the option of doing a stained finish. The edge of birch plywood can look interesting.Is there a specific reason you are against use of screws?
I must have missed something in physics class.Lighter and denser?
Sorry, lighter and more stiff. Apologies.Lighter and denser?
A butt join will be fine, just make sure you clamp them tight as they dry and if you want to run a bead of sealant along the interior joins. Providing you cuts are good (square) and it clamped well as it drys you wont have a problem with air leaking or strength :TI have built speakers out of MDF before and used butt joints. If the edges are nice and straight the joints seem pretty air tight and strong (using just glue).
Can/should I use simple butt joints with Birch plywood? I don't plan on using any fasteners.
Another alternative I have is mitered joints with biscuits.
What is the recommended joint?
I took this advice. Not sure I needed it, my edges were really clean this time (used a router to make sure they were all square). I used biscuits and wood glue. I also used a bead of liquid nails on the inside edge of each joint. I am pretty sure the seams are going to be the least of my air-leakage problems (cut a little too big of a cut-out for the driver ).I always use liquid nails around all seems on the inside of my boxes.Just be sure the liquid nails is dry before making a spark. :bigsmile: