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Loudspeaker Designs and Articles for the DIY Enthusiast
Jim Holtz's:
Anthologys
Enclosure Design
Jim: My goal for the enclosure was to reduce the overall height to equal a monitor sized MTM on a stand. I also wanted a simple to build cabinet that would
not be too complicated for builder’s new to DIY to tackle. Another goal was to use 6” PVC for the mid tunnel to take advantage of simplicity of construction.

The cabinet measures 48”H x 11 1/2”W x 15 ½”D with a 1 1/2” thick front baffle and several horizontal window pane brace to add extra stiffness to the
cabinet. I also added PVC support baffles to hold the PVC tubes in place while adding extra stiffness to the top half of the cabinet. The cabinet is
constructed entirely of ¾” MDF and the woofer compartment is lined with 2” wedge foam everywhere you can see when looking into the cabinet through the
woofer cutouts.

I mounted the PVC mid tunnels by cutting a front and back piece of 3/4” MDF 18” x 10” with a 6 5/8” cutout to hold the PVC rigidly in place both front and
rear with the support adding to the cabinet stiffness by increasing the back half of the cabinet to 1 ½” thick and the front half to 2 ¼” thick. The PVC butts
tightly against both front and back for additional stiffness. I did a ¾” round over to the inside of the front baffle for a smooth transition and to eliminate any
chance of “tunnel effect” on the driver. The PVC I used is the thick walled variety that measures 6 5/8” OD and 6” ID. I cut the mid tunnel PVC to 13 1/4”
long. The mid tunnels are lined with 1” flat foam that extends from the rear magnet edge of the driver to the rear of the cabinet. I also use a 45 degree angle
cut on the driver end of the foam for a smoother transition of the rear sound wave.  We used a 3” Precision Port with inner and outer flares. The actual tube
length is 5”plus flares for an F/3 of around 32 Hz.

 

Statement II performance
in a smaller, more cost
effective package?
You be the judge...
Links to:

Main / Design Goals

Driver Selection

Cabinet Construction

Crossover Design

Measurements

Listening Impressions