The Sonotube route worked well for me, not having a table saw or wood shop. Alls that is needed is a jig saw, staple gun and a drill.
I was lucky to have a company that sold the sonotubes near by and they had some offcut 24" diameter pieces they cut to 24" tall. They were nice enough to give them both to me at no cost.
The end caps are 3/4" mdf that were cut for me at Home Depot coming home with 24" x 24" pieces then cut to circles with the jigsaw.
They are covered in flat black naugahyde/vinyl material purchased at Joann Fabric wrapped around the tube that looks really nice. The top of the tube is covered with 3/8" plywood cut in a circle covered with the material and glued on the top to cover the staples where the material is attached.
The feet are 1/2" x 6" carriage bolts covered with black automotive tubing to cover the bolt. They are very strong and sturdy.
I wish I had taken pictures through the steps of building them.
The original drivers were Kicker 18" drivers which I have switched out with 18" ED 190v.2 drivers. The Kickers had a bit more punch but the ED's put out alot more overall volume. They are driven by a Behringer EP2500 bridged.
They sound great and really rock the room.