STEP 1: I started with a sheet of 14mm MDF (use thicker MDF for larger boxes) and cut a piece to fit the base and another for the back. nail or staple them together (i used small tack nails).



STEP 2: cut your speaker rings in the sizes you need and position them where you want the speakers to sit. making the bits to support the rings can be a bit tricky and some of it will be just guess work. once you have figured that out you can nail it all together.



STEP 3: find a material that stretches both ways (i found mine at a fabrics shop) and staple it onto your MDF frame making sure that the staples arnt visible, there are no wrinkles and creases in the material and that the mdf frame dosnt make any shape points in the material that you will see when its finished (i had to change my frame slightly for this).



STEP 4: give the whole thing a thick coat of fibreglass resin and let it dry because if the fibregalss is put on all at once it could make the material sag more than desired. (a litre of resin costs about $20)



STEP 5: get some fairly thin fibreglass matting and cut it into sections to fit. put another coat of resin on (only thin this time) and lay your matting on and then more resin on top of that. once its dried you can cut off all the daggy bits of material from around the edges and pull the staples out that were holding the material.



STEP 6: get some car body filler and cover the box with just enough to fill the lines that the fibreglass makes otherwise it will take too long to sand smooth.



STEP 7: simply sand the filler until its smooth.



STEP 8: spray it with some spray putty/primer to fill in all the pits and lines made by the sand paper.



STEP 9: a few coats of paint and your all done.