Made this sunday night due to extreme boredom. Used a couple of 4" woofers out of some high end bookshelf speakers that had burnt tweeters. The construction is kinda cheesy- epoxy for all of the joints(no mechanical fasteners), and PVC for the port tubes, no terminal plate in the back(hole drilled with wire sealed by epoxy). Im guessing that it's tuned around 80 hz- I nearly copied the original port volume, and the box is pretty close too. I didn't have any specs on the drivers, so I just had to fudge it. Surprise- it actually didn't end up sounding that bad. Obviously it doesn't do squat with the B string, but it does barely manage to fart out a little bit of the E. Anything higher than that it actually sounds pretty good. I was playing a few melodies with chorus last night quite loudly without breakup. It does a fine job as a practice cab on my dresser. The impedance of each driver is 4 ohms, so I wired them in series, and ran them off of one channel of my PLX1602(300watts RMS @ 8 ohms) and had no sign of heat from the front of the cone or coming off of the magnet after an hour of playing, so obviously the oversized motor structure on these little guys isn't there just for looks. Eventually I think I'll buy an eight and build a simple crossover for a little more lows.