Parts of the Cabinet

• There are three components to a Leslie speaker cabinet: a top shelf that houses the treble horn, a middle box that houses the high and low drivers along with the crossover, and a bottom shelf that houses the low frequency rotor and amp. Traditionally, the Leslie speaker cabinet houses a tube amp, but you can use your own non-Leslie equipment if you prefer.
  
  The middle box that makes up your Leslie speaker cabinet should be large enough so that your drivers have plenty of clearance on all sides. The other shelves just need to be large enough to house the horns, rotors and amp.
  
  Leslie amps also have louvers, or long and narrow holes, that let out the treble sound in the top of the cabinet and the bass in the bottom.
  
  

Building the Cabinet

• You should construct the outer box shape from 26mm MDF. You can make the cuts yourself of have your local lumberyard do the work. When you put your box together, you'll want a top, bottom, two sides, and front. You won't want to put a back on the cabinet until you've installed the speakers, horn and amps. Use a 90 degree clamp to hold the corners of the box together as you're working, then use wood glue on each corner of the box. Once the wood glue has dried, you can screw the sides together. After you've constructed the large box, it's time to install the shelves.
  
  Screw triangular pieces of wood into the corners of the box to brace it so that it doesn't vibrate too much when the speakers are on. Next, cut the louvers. Use a plunge router to cut two columns of eight louvers on the bottom of the cabinet and two columns of four louvers in the top.
  
  Next, build the baffle board, which holds your drivers and makes up the middle box in the cabinet. A good way to make a custom baffle board is to lay the drivers down on some newspaper to make a template. Trace around the circular drivers and make cuts, because the drivers will mount to the board, and you don't want the wood covering the speakers. Once you have your template, cut scrap wood to size. Then, mount your drivers to the baffle board, and mount your baffle board inside your cabinet.
  
  

Finishing

• When you're finished building your cabinet, you can achieve a classic Leslie cabinet look if you attach birch veneer to your MDF. However, you could also use paint or varnish to achieve a finished look.