I can't really say I made these more than I just put it together. My brother had some nice Boston Acoustic 6X9's from the old boat. We planned on putting them as tower speakers on the new boat but never purchased a speaker box for them. We really like the looks of wetboxtowers but the price is a bit high. I remembered I had some 6X9 speaker boxes that I purchased a couple of years ago for $30 from Crutchfield. They are well made and are covered in carpet. For tower speaker clamps I used "billet bar mounts" that I got for $50 from www.chassisshop.com
. Ran the speaker wire through the tower and connected them to an amp and Voila... Tower Speakers.
Cons- Tower Speaker boxes are made out of MDF and carpet. Could be problems if they get wet. The tower speaker clamps are not quick release and cannot be easily removed. Not too concerned about it because I garage my boat.
Pros - Relatively cheap. total cost for materials and wire - less that $100. The only major cost comes from the quality of speaker and amps that you buy.
Here are some pics