Celestion 15" bass W-Bin design 
Use MDF or ply - if you dont have a router to cut the guide grooves for the inner panels, then use batons as the plans say to keep them in place. To build this you gotta build the middle bit on top of one side so to speak, then drop the other side on top - the inner chambers are held in place by the side panels in essence... then add top/bottom/rear panels etc - line-up is important therefore and you need to dry-test fully and mirror the guides on either opposing panel.
15" Bass Scoop Rear Horn Loaded Cabinet
Ideal for club and party systems. A couple of these with top flyers will be ok for small club/bar. Here's a rear horn loaded bass scoop-bin. It's NOT easy to build..... so get a wood-friendly mate to help - preferably, get the wood yard to cut the parts to the plan.
Use the pair of these with any stereo power amp up to 500 watts per channel...but ease the volume in huh!......dont blow the things up !! You can build another pair, and add them together with the first pair for more power. I was in a small club recently... about 800 sq ft with a low ceiling, and they had 2 of these, with 4 mid/treble flyers up on the walls. It was nice and loud.
Cut out the side panels first... Lay one out flat, and draw out the plan on that, and use it as a guide.... Make sure all the Mitreing (angled joints) are well cut and accurate. On the plan fixed to the underside of the curved panel, is what looks like a small square... This is a length of planed baton of say 1-1/2" - 2" square which is fixed between the 2 side panels, and supports the curved sheet. The entire cabinet opening has a planed hardwood baton all around the side and bottom inside-edge of the opening. The bottom baton will support the bottom of the curved sheet when you drop it into place.....The sides of the curved sheet must be flush with the inner-cabinet side panels - in other words - cut it with perfect 90 degree corners.
OK, once you've marked out the side panel(s) as a guide, created all the inner baffles and their bracing struts (where added) and put the sides, top and bottom together leave the curved sheet till last. Now... get the first ply sheet, screw & glue the supporting baton to it right across it's centre line, so the baton ends are flush with the edges of the ply sheet. This curved sheet is dropped into place, with the bottom edge mating with the cabinet opening, bottom-edge baton that runs along the inner bottom edge of the opening. The top edge is glued and tacked to the inner back panel, on the drawn line where it should meet - creating a curve. Put lots of PVA glue on the sheet edges. Tack the top and bottom edges... the sides will be fixed by the glue. OK, if possible, once the first curved sheet is in place, screw through from the outside of the cabinet side-panels into the curved sheet-supporting-baton ends that meet with the cabinet inner sides (the baton that runs across the center of the curved sheet).
Now, when it's all dried (the next day). Add the second sheet to create a strong laminate (layered sheet). OK, the first sheet is in place and fixed. To create the laminate, you need a different glue. Unibond or Evostick (the glue that gets you high !!). The second sheet should be the exact size as the firs. Cover the first sheet with a THIN layer of glue (thin means thin ok !!). Cover the second sheet with a thin layer. Wait until they are tacky - then drop in the second sheet. Line up the upper edge and smooth it down over the first sheet. Get it lined up right, cos once the glue sticks, your f**ked.
However, the inner cabinet sides will guide it into place. Just take care - Once it's dry...(about 1 hour), smear some PVA glue around the edges where the curved sheet meets the cabinet panels. Let that dry and you'll have a nice solid curved panel.
Right, also on the plan, in the XX-Section, is something marked "BRACING STRUTS". These are right on the vertical center line, and are made from the 3/4" sheet, there are 2 pieces and they mate with, and support, the 2 largest inner baffles adding support to the center-line of these baffles. Best bet, is to cut all the inner baffle sheets, and lay them out standing up on one of the side panels you have marked out. Cut the Brace as a single piece, then lay the inner baffles over it at the correct angles then mark it across the center, and cut it in half (cutting out a thin slice, exactly the width of the 3/4 inc baffle that it will mate with). Use lots of woodglue (PVA) on the edges when putting it all together.
