I actually threw in the towel on my cabinets for now. The plywood is such junk I can't stand to devote any more time on it. I cut the hole for the tweeter and the outer ply tore off all the way to the woofer hole. No wood taken with it on either side. The glue just failed. I called Lowes and have to call back tomorrow but I'm shooting for a refund and might dispute the CC charge. It's just $160 worth of junk. It's getting hard for anyone that doesn't protest or play video games for fun.
I ordered 3 sheets of MDO from a place somewhat nearby called Harbor sales. It's called Medex. Supposed to be somewhat moisture resistant which is pretty immaterial but their talking formaldehyde free adhesive which makes me nervous. A lot of "friendly" adhesives seem weaker. They say 30 days till it ships so I might try to get Lowes to give me MDF in exchange, but I am starting to think everything they sell at those big stores is of a lesser grade.
I have nearly all the steel and wood to build an ultralight airplane. It's called a Legal Eagle. The project never really got off the ground, so to speak. I paid $2500 for that order 7 years ago. Paid extra for German steel tube. I can't imagine what that would cost today. I'm sure most of it is not available.