Using the Dayton 0.75 cubic foot two-way cabinet made
building my prototype easy. With the unique "B-Rex" baffle
removal system, recessing and cutting the driver holes was a
snap. I chose the cherry cabinet (#302-732) because I like the
finish and it will go with the rest of my furniture. I just love this
job! In keeping with the "high-end" theme, I decided to use our
new brushed aluminum bi-amp plates with the premium binding
posts. I went with the black anodized plate (#091-612), satin
nickel binding posts (#091-624) and the satin nickel jumpers
(#091-654) because it looks cool.
Construction tips: Over the years, I've had the pleasure of building many systems using the Dayton cabinets. Listed here are just a few tips that may help make building your speaker project a more enjoyable experience.
- Minimize the number of times you handle the cabinet during construction. I try to keep the protective "pearl" wrap on the cabinets as long as possible through the construction process and store them in the shipping carton until needed.
- When working on the cabinets, I like to cover my work surface with a soft cloth or carpet. I use our cabinet carpet (#260-765). It doesn't have the "stiff backing" commonly found on carpet; it's soft and inexpensive.
- Before making any cuts to the baffle or cabinet I recommend putting masking tape over the surface being cut. I prefer using the "blue" painters masking tape due to its low adhesive properties. The masking tape will protect the surface from scratches caused by the circle jig and help minimize "chip out" from the router bit. The masking tape will also make it easier to see your pencil marks showing hole locations.
- When mortising or recessing drivers, make your recess a hair deeper than the thickness of the faceplate or mounting frame. This will allow room for gaskets or sealing caulk. When cutting your mortise or holes, it is better to make several shallow cuts than one deep cut. Again, this will help reduce "chip out" and burning up the router bit. After you cut your mortise and mounting hole, take a wide black permanent marker and lightly go over the cut so you do not see a "tan MDF" ring around your drivers.
- Pre-drill all screw mounting holes. This helps keep the wood veneer/MDF from splitting and the screwdriver from slipping.
- Last but certainly not least, I remember what my high school wood shop teacher used to say, "Measure twice and cut once".
After removing the cabinets from their shipping cartons,
unscrew the screws holding each blank baffle and separate
them from the cabinet. With the baffles removed we can now
lay out the driver placement and make our cuts. The tweeter
and woofer will be centered (left to right) on the baffle. The
spacing between the tweeter and woofer is critical due to the
crossover frequency so please adhere to the measurements
below. The center of the tweeter opening is 4-1/2" from the top
of the baffle. The center of the woofer opening is 6" below the
center of the tweeter. Mark both locations and drill a small 1/8"
hole. Using a Jasper circle jig and plunge router, cut the woofer
mortise (recess) to a depth of 1/4" on a 6-15/16" diameter.
Then cut the woofer through-hole to a diameter of 6-1/4". Next,
cut the tweeter mortise to a depth of 1/8" on a 4-1/8" diameter.
Then cut the tweeter through-hole to a diameter of 2-15/16".
You will need to "notch" out the hole to allow room for the
terminals. Repeat these steps with the second baffle.
The next step is to mount the port tube to the back of the
cabinet. The port tube should be located directly behind the
tweeter. This location positions the interior flare directly in the
center of the internal brace opening guaranteeing minimal
obstruction of the port. The port will be centered (left to right)
and the center of the port through-hole will be 4-1/2" down from
the top of the cabinet (just like the tweeter on the front baffle).
Mark the location and drill a 1/8" hole. Again, using the circle jig
and router, cut the port mortise to a depth of 1/8" on a 5-1/4"
diameter. Next, cut the port through-hole to a 4" diameter. Cut
the 2" ID tube that connects the two flares to a length of 1-1/4".
The total length of the assembled port tube will be 6-1/4". Due
to the fact the interior flare is a larger diameter (4-1/4") versus
the port through-hole (4"), the port tube should be assembled inside the cabinet. First install the (larger) outer flare into the
cabinet back wall. The outer port flare is a press fit design and
should fit snug in the hole. Place a small amount of RTV sealant
around the mounting flange before installing in the cabinet. Attach
the 2" ID tube to the interior flare using an ABS adhesive. From
the front of the cabinet attach this assembly to the outer flare
through the opening in the internal brace using the same ABS
adhesive. Repeat these steps with the second cabinet.
I really like our new brushed aluminum bi-amp plates. They have
a beveled edge and look great even when surface mounted. All
you need to do is drill four 5/8" diameter holes for your wires and
to clear the binding post's mounting nuts. You can use the plate
as a template for the hole locations. The Dayton cabinets come
with two pre-drilled 1/4" holes on 3/4" centers. I filled these holes
with RTV sealant, drilled my four new holes and then covered
everything up with the bi-amp plate. I then mounted the assembled
crossover boards (see crossover design below) in the cabinet
using Gorilla glue (#340-004). I placed the woofer crossover to
the rear and bottom of the cabinet due to it having the heaviest
inductor. I glued the tweeter crossover to the rear and side of the
cabinet next to the woofer crossover. The input leads were then
soldered to the binding posts observing correct polarity using the
top set for the tweeter. Remember to install the jumpers if you are
not planning on bi-amping the system.
The cabinet should be fully lined using our 1-1/2" acoustic foam
(#260-516). If done correctly one sheet is enough for each
cabinet. 3M's Super 77 (#340-255) is the perfect adhesive for
attaching the foam to the cabinet walls.
It is now time to attach the front baffle to the cabinet. Apply a very
small amount of Gorilla glue (#340-004) to the rabbet edge of
the cabinet and install the baffle. Do not use too much, because
polyurethane glue expands and if you are not careful you may get
it on the cabinet finish. Secure the baffle in place using the four
screws located on the outer corners.
When connecting the drivers be sure to observe proper polarity
and connect the crossover to the driver for which it was intended.
During mounting, make sure you use the gaskets supplied
with the drivers to ensure an airtight seal to the cabinet. The
Usher drivers have very small mounting holes so I used #6x3/4"
decorative head wood screws (#360-840). They give a more
professional finished look to the system.