We have started a variation of the Legacy Marquis. The difference between our "MarquisPlus Project" and the Legacy Marquis is as follows. The Legacy Marquis uses two single 15"s, one Eton 7", one textile dome, and one ribbon tweeter. The "MarquisPlus Project" uses 2 pair of doubled 15"s, ala the Whisper, and, 2 of the Eton 7' and one Focal TC-120 tweeter, in a classic MTM array.
Laminating up 2, 3/4" pieces of MDF. They were "pinned" in place with a brad nailer using 1 1/4" wire brads. The 2"X2"s are used as spring clamps to increase the pressure on the middle of the panels and eliminate voids.
After laminating the MDF pieces together, one side of each baffle was laminated with Wilson Art "Figured Mahogany" high pressure laminate. These will be the insides of the front and back baffle. They can't be laminated after assembly. So it's done at this stage and then used as a "drafting table" for layout of the drivers. The process of layout is done using horizontal and vertical center lines. The drivers are "indexed" of these lines. Circles are then scribed around each driver, the center lines are created by bisecting with a compass. There were no printed plans for this speaker. I "made it up" as I went along. For this project, the prototype and finished product are one in the same.
This is the layout for the drivers. The centerlines will be marked for drilling the router pivot hole.
With layout completed, the pivot holes are drilled using this portable rig. It's handy because it keeps the drill perpendicular to the panel. This is very important when using the routing jig.
Here are both baffles. The plunge router has a Jasper Audio speaker routing jig attached. It was used to make all the openings, as well as the recesses for the woofer insets. Obviously the laminate side is down. The sides as you see then here are, the outside front, seen at the bottom of the picture, and outside back at the top
This is another view of the front baffle while the last cut is being made. The openings for the Eton 7" have been "eased" with a 1/2" round over bit. This unfortunately doesn't show up to well in the picture. The "recesses" for the woofers are approximately 1/2" deep.
It was necessary to fabricate a routing jig to cut the arc at the top of the baffle. This picture was shot while the final adjustments were being made to the jig. The radius for the arc is 36". The pivot point distance is well off the edge of the baffle, this was necessary to create an arc with the proper edge spacing from the drivers.
This is a picture of the jig in action. The cut is made in many passes. The router has a solid carbide "up cut" spiral bit. This means, that as it cuts, the bit pulls the wood up, out of the hole. Yes, that's snow in the background.
Once the rough cut was finished, a carbide roller bearing bit was used to smooth out the edge.
The cut out for the tweeter panel was made in a table saw. The panel is placed over the lowered blade. The saw is turned on and the blade is raised. This creates a very finished looking opening.
This is a view of the back side of the panel after making the cut out for the tweeter panel. The circular saw of course "over cuts" the back side of the panel. Here you see the "over cuts" being filled with epoxy. The clamps are holding dams made from scrap MDF wrapped with wax paper. Quick setting epoxy was used to over fill the saw kerfs. The excess is easily removed with a wood file.
This is the layout with the drivers in their respective openings. The parallel lines from top to bottom between the woofers and 7"s are where the MDF sides will be for the sub-enclosure.
The sub-enclosure is just a simple box made with 3/4" MDF. The black line around the top of the box is a decorative edge detail, done with the router and a "beading" bit. It's painted with a black satin enamel. Here it's also possible to see the edge laminate. Due to the arc, the ends of the laminate are held in place over night with duct tape to make sure they don't spring up as the adhesive sets.
Here the sub-enclosure is being aligned, prior to it's being attached. There are speaker inputs for each of the 15"s on this side of the baffle. The rear baffle will be centered between the inputs when the speaker is completed.
At this stage, the speaker is approximately 65% completed.
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