rh2music wrote:Hi, I want to build 2 12" speaker cabinets for guitar. I want to know if anyone has ideas on what type of wood to use and construction methods.
My idea is to build open back cabinets.
There is not much to designing an open back cab. Make it as large as you can stand, the larger the baffel the beter the bass will be but ballance that with the need to stor and transport the cab.
"open" cabs are really only about 30% open. 2/3rds of the back is covered. So there is a slot about 1/3rd the hight of the cab where the sound comes out. Place this slot lower then center, nerer to the bottom. This makes the distance from the slot to the front (over the top) larger, Same effect as making the baffel larger. The flor blocks the path under the cab to the front so a low slot causes no harm
Construction depends on your skills and equipment. Best is to use hardwood plywood and finger joints. This is very strong. But I'm sure that patical board and drywall screws will sound the same and might last for many weeks. A compromise is simple but joints reinforced with 1x1 battens in the corners and wood screws
I recently finally learned to make finger joints. It's easy. My first try worked. The trick is to make an accurate jig. After that no skill is involved. Google for on-line box joint turorials. There are many.
After making some test parts with finger joints and but joints I gave them the old "sledg hammer test" and knock them apart with a 5 pound hammer. Result? Finger joints are very strong in quality plywood. They make the joint much stronger than a simple butt However in white pine they are wasted as the wood itself fails first. With pine the strongest joint is made by gorilla glueing and screwing 1 inch square hardwood to the inside iof the joints..