Having settled upon b/bb birch ply for the panels (panels cut to size by my friendly local timber merchants, now lurking in my workshop) I am contemplating further design options. Firstly: Mixing materials. I assume that using mdf for some of the internal bracing instead of more expensive ply is OK (?), as I need to keep costs down (my original budget of £100 already exceeded). I have enough ply for the panels and top and bottom, but not for all the bracing. Shouldn't be a problem should it? I'm also using pine handrails to fashion the corner fixings (needed as none of the corners are 90 degrees), not ideal but hardwood poles are gonna be just too expensive. I don't have the tools to cut the complex angles for the corner fixings specified on the original plans.....and I intend to extend the poles slightly above and below the panels for an interesting 'look' :D . Secondly: I'm doubling up the panel thickness on the baffle, but is it better to use pva wood glue or a grip adhesive (e.g. gripfill max or equiv.) to bond the two panels together? I'm going to screw them also (from the rear to keep them hidden). Thirdly: Port location/size/shape. As I understand it the length of the port can be altered to 'tune' the cabs in some way (:confused: ). But, is the location of the port(s) critical i.e. positioned centrally, or a pair, high on the baffle or down low? I had also contemplated copying the V-shaped ports on the Tannoy Churchill cabs, does the shape alter the sound? Fourthly: Where can I buy acoustic foam from, and what type is best? Anyone got a big pile of it going begging? :D