I found a speaker building buddy who happened to live in my neighborhood. The first time I went to his house he had a line array using 9 three inch drivers per side and 9 small tweeters. This reminded me about the 16 I had in my garage. After listening to his I knew I needed to put my drivers to good use. Dave suggested I pair them up with a different tweeter than he used. He used a ¾ inch dome tweeter and recommended the same driver that had a 5/8 inch dome. He had used this tweeter in a couple other projects and really liked them.
I had 16 of these
and ordered 16 of these for use as my tweeter
Dave had substantial experience with speaker design, after measuring my little woofers designed a great crossover. With 8 drivers I chose to wire them 4 in Parallel and then the two sets of paralleled drivers in series giving me roughly a 4 ohm load. This was taken into account for the crossover design. See the theoretical frequency response graph.
(for two speakers:)
(2) 2.4 Ohm Resistor
(2) 3.3 uF Capacitor
(2) 7.5 uF Capacitor
(2) 10 uF Capacitor
(2) .70 mH Inductor
(2).15 mH Inductor
(2) Speaker terminals
(for two speakers:)
½ ” Birch plywood
(2) Front Panel 7” X 34”
(2) Rear Panel 7” X 34”
¾ ” Birch Plywood
(4) Top and Bottom 3” X 5.5”
(4) Side panels 3” X 34”
20 feet of Black 18 gauge wire
20 feet of Red 18 gauge wire
Semi Gloss Polyurethane
Mounting Screws for the 3” drivers
One bag of Poly Stuffing to act as acoustic insulation in the cabinet
Mounting screws for the rear panel.
Electrical Tape or Heat Shrink Tubing
Hot Glue Gun (with a bunch of glue sticks!)
For the cabinet I chose 13 ply birch plywood. In the Dallas area you can get it here
. I wanted the line array to be small and compact. And, easy to build with the tools I have. I drew the front panel in inkscape
(Great Open Source drawing program!) Because the tweeters were so small I decided to just drill the right size hole and then glue the driver in flush to the front panel. I experimented with a 1 ¼” hole and a 1 3/8” hole and ended ordering a 1 5/16” forstner bit from here
that was just right.