I just thought I would share a DIY project I just finished, good for someone looking for a easy, starter project or something to use up some old drivers on for a little bit of fun. Basically, I constructed my twin "mini-towers" in a total of about 2 hours of actual labor (that is, excluding glue/sealant/primer/paint drying time) with nothing more than a drill, jigsaw, and screwdriver. Here is the story: I was browsing Home Depot for some wood wire channels to conceal my rear speaker wiring around the baseboards of my living room and I ended up in the lumber section (I am sure there are others out there that end up just walking the entire store). In the lumber section I found 12 inch MDF and plywood circle cutouts for projects, and the idea hit. I grabbed a few of those and went over to the concrete section. I pulled down the 12 inch sonotube (actually sold as Quickrete tube) and saw if they fit. The tube is actually shipped with 3 of the same size tubes packed inside each other, so there is about a 1/3 inch diameter difference in them. I found the middle size was a perfect, tight fit for the cutouts I had. I grabbed a tube (48 inches), 8 3/4 MDF 12 inch cutouts, and some silicon and headed home. I had 4 8" drivers I had gotten on a closeout from MCM laying around from a previous failed project (nothing special at all, but I had all of the T/S parameters and I had bought them for $8 each. Perfect project fodder). I jumped online, grabbed some cylinder volume translations and WinISD, and found the idea length for 2 drivers in my tube was 19 inches. Cut the tube in half, add the end caps (which I actually had glued two round pieces together to make 1 1/2 inch end caps) and figure the space the drivers took up, and I was close enought for gov't work. The rest was simple sonosub building. Drill the cutouts for the speakers and wire terminals in the end caps. Fix the end caps on (with brads and liquid nails). Seal, wire and plug in drivers. I finished it all up with gloss black spray paint over a few layers of primer. I then put 3 3 inch legs on the bottom of each for the stand. The result: 2 small sonosubs that fix behind my couch, and that provide surprisingly good sound for the fact that I spent less than $100 TOTAL for the 2 complete subs (including the drivers). The better result: knowledge that I can use if I do decide to make a Shiva water heater sub that I could have only learned one way, by trial and error. I just thought I would share this for anyone that was like me that wanted to make a sonotube but was afraid to lay out the cash for components just to find out your couldn't do it, or made a crappy sub. Experiment and gain confidence with this little a little project like this, and your ultimate goal will be 10x better. Plus you will then have a good set for to use on your rear surrounds, 2nd system, or just about anything else. Have fun!