The whole idea is that the transmission-line is tapered. The top of the internal baffle
divides the cabinet into thirds, with two thirds of the space on the woofer side and
one third on the port side (that sounds funny, doesn't it?) That makes the top spacer
2" wide. At the bottom of the cabinet it gets a bit trickier as the baffle doesn't
reach all the way down. Using the lower spacer block listed in the parts page, you
can cut the baffle to the same length as the sides and use the spacer block to locate
it. After drawing the lines and the witness marks, cross-cut the baffle to its
The first step is to rip the front, back and side panels and the internal baffle to
size. All are 8" wide and 42" long. The internal baffle is then cut to a 36" length.
Here we see the side panel laying flat on the bench with the back and internal baffle
standing on edge. The top of the speaker cabinet is closest. Note the spacer block between
the back and internal baffle.
Also note that the quick clamp is holding the back square to the side. With the spacer
blocks in place at both ends of the baffle, draw a line along the junction of the baffle
and the side along with the witness marks for the biscuit joints.