Cabinet Dry-Fitting

This second section describes the initial dry-fitting of components.

This first photo shows the five Parts Express boxes lined up for initial dry fitting of components. The Gloss Black cabinets are for the Casitas and the Yellow Maple are for the Kitty Kats. Five Boxes lined up for initial dry-fitting and measuring Click for Hi Res Version

The North Creek cabinet designs are robust and very well braced. The Parts Express cabinets are very good and a great value but are not as soundly braced. We wanted to have as dead a cabinet as we could afford while basing the design on the North Creek methods. The North Creek designs have extra bracing made of plywood and spaced so as to reduce panel vibrations. We were concerned with the solidness of the Parts Express cabinets and especially the sound of the side panels near the front when rapped hard with the knuckles. We decided to add some additional bracing following the North Creek design concept. To help determine where the bracing should go we decided to dry fit the drivers and fascia to see how things would line up.

The drivers were temporarily mounted on the North Creek Fascia and the crossovers placed in the cabinets to check fit. If you look carefully in the following photos, you can see the 1.5" diameter hole drilled in the top center of the box for the flared vent tube.

The Casita with the larger woofer, silver tweeter, and Gloss Black cabinet is on the left, and the Kitty Kat with the smaller woofer and black tweeter is on the right. (The tweeters otherwise look identical except for the color. The black ones are nearly two years newer than the silver ones.)

Boxes set up for dry-fitting Click for Hi Res Version

In the Casita cabinet the crossover is set with the large air-core inductor located in the back bottom of the cabinet directly beneath the binding post holes. One single wire then comes to the front half of the woofer crossover which is mounted in the front bottom of the cabinet. The tweeter crossover (resting on the table in front) is mounted on the back panel, horizontally centered between the 1.5" port tube hole and the binding post holes.

Casita cabinet with crossover Click for Hi Res Version

This photo shows the back side of the front panel with the drivers dry mounted. Notice the routed round-over of the backside of the MDF and plywood for the woofer. These will be sanded smooth and sealed for a smooth edge so as not to interfere with the backside airflow of the woofer. Also notice how close the bottom of the woofer motor magnet assembly is to the top of the crossover. Care must be take to insure that there is no interference during final assembly.

Casita cabinet with front panel drivers mounted for dry-fit Click for Hi Res Version

The following photo shows the Kitty Kat cabinet with the crossover for the woofer inside the box and the tweeter crossover resting on the table in front of the box. If you look closely, you can see the woofer inductor behind the internal brace, and the balance of the crossover sitting at a slight angle with the left side higher than the right. The crossover is a small bit too wide to fit withing the internal width of the cabinet. It is clear from this dry-fit, that the baseboard of the crossover will have to be shortened to fit properly especially after the North Creek glop is applied to the two sides.

Kitty Kat cabinet with crossovers Click for Hi Res Version

The following photo shows the Kitty Kat cabinet with the front panel and temporary mounted drivers. This was done to help us locate the braces we wish to add between the provided center brace and the front opening. As you can see, the modified magnet motor of the woofer is quite deep, and we were concerned that the brace not interfere with the motor. Also of concern is the clearance under the magnets where the crossover will be mounted.

Click for Hi Res Version

Please see the next article in the series Bracing and Glop

Copyright © 2010 David L. Bytheway