"""Why is the bottom one ported (3 ports?) and the top on sealed?
Wes""
The bottom was done months earlier and on the second cab/combo I decided to put the 3 ports to the rear. Same reason the bottom cab speaker mounting is different--the bottom positioning was to make room for the ports. I wish I hadn't put the ports on the front with the lower cab. So essentially, I didn't go for an exact match. I wanted to improve on the initial design. Mostly I'll use the combo alone so it wasn't a priority.
As to the carpet question:--I'd rather touch up wood cabs from time-to-time than deal with rat fur. As much as I gig--rat fur looks pretty bad within a few months.
As to the duratex--would have been ok but I like wood, and the duratex is expensive for small jobs. I wanted to see how light & cheap I could make a good sounding cab. Once the cab proves itself--I may pop for bedliner.
"block the fan or vent"
the fan is actually on the right side. The Shuttle vent (that looks like a 2nd fan opening) is on the left side. I left a small gap between the side of the casing and the left wall of the combo which should allow incoming air to pass. I did that but am not positive that was the main source of incoming air. The vent for the tube on top also has clearance.
3-ports? ---what you end up with for ports are dictated by materials, size of cab, and desired frequency and/or speaker protection issues. So I decided on the port size 1.5" and the software is going to tell me how many and how long the ports must be.
My goal was to get a light as possible--and use materials I already had on hand. The cost of the second cab/combo was $23 for plywood, $5 for finish, already had speaker, corners and a grill, and used ports from plumbing supplies. The first cab was maybe $60 (wo speaker)
End result is a 600w combo that weighs 33 lbs and sounds good, didn't cost $800 to $1,000 (like the Shuttle or Markbass combos), and provides a home for the amp--plus tuner, wireless base unit, and power strip. There are very few if any combos that would have accomodated mounting the extra stuff into one compact unit, stayed light, and allowed for quick setup and teardown.
good one
