Illumina 66 cabinets
Copyright 2012-15 Troels Gravesen

GO TO ILLUMINA 66 CONSTRUCTION PAGE

 


Click image to view large.


Sketch-up file can be downloaded here.
Program for viewing skp file here.
Thanks to NN for making the file!


For sides, rear and top panel I use a laminate of 9 mm Baltic birch and 19 mm MDF, a total of 28 mm.
Bending the side panels takes a rig and here you can see the simple set-up made from wedges cut 10 and 20 deg.
Before bending the side panel, apply water with a brush to moisturize the outer veneer. Leave it for 10 min. before bending.
If you don't apply water, the outer veneer will crack.


5-6 clamps are used until glue has settled. Leave for two hours.


Make 6 bracing panels after having bent the side panels. This way we're sure of a perfect fit.
Make two holes of 100 and 140 mm diameter.


For gluing side panels and rear panel these fillets were made, cut 20 deg.


Excess side panel was removed with the router.


Left: First time set-up to get an idea of final shape and size.
Top panel is the tricky part here and if made as seen on photos, a belt sander is excellent to make a perfect fit.


Small mahogany wedges made to fill the holes.
The side panels are cut to a depth of approx 2 mm from the outer side, middle of second layer of veneer.


Bitumen pads, 4 mm, glued to all side panel sections of cabinet.


Several test front panels were made to make the smoothest response from the 6600 tweeter.


The upper faceting of front panel was made on my table saw. Doing the side faceting I did by hand. It can be done on the table saw but setting up a suitable rig takes much longer than doing it by hand. Only tools needed are a chisel, planer and sand paper: http://www.troelsgravesen.dk/SP44.htm#FRONT PANELS 


Front panels made from 2 x 16 mm black MDF. This material seems like HDF, very heavy with an almost ceramic quality to it.
Easy to saw, easy for routing, easy for sanding - but the black dust from the table saw is a pain despite proper ventilation.

Trying out the drivers' rebates. Drivers with fixed rubber foam gaskets are a bit tricky as we need to route a little deeper so that the compression of the gaskets will fit with the tension of the screws to make flush mounting. With the new ScanSpeak tweeters this is no longer a problem as the gasket fits into a shallow recession of the face plate allowing us to route as deep as the measured thickness of the face plate.
As always, make test routing for drivers as a 1-2 mm gap just doesn't look good. I also strongly suggest gluing a block of MDF behind tweeter hole to seal off the tweeter from the back pressure of the 18WU driver. The 6600 tweeter is rather shallow and only takes some 28 mm depth.


Left: Gluing blocks of stacked plywood for the screws holding the base plate.
Right: Sanding by hand is tedious but in fact didn't take long. Use a wooden block to make smooth and plane surfaces.
Initially I used grade 80 to smooth the table saw cuts and finished with grade 150 before lacquer was applied.
Faceting can be made with a good chisel and sanding paper only, check here: http://www.troelsgravesen.dk/SP44.htm 
- and this is actually faster than using a table saw as was done here.


Make two blocks of MDF to seal off the tweeter. If you stick to the 6600 tweeter you don't need to increase depth as done here.


Trying out the front panels with drivers and the base plate to see how the final speaker will appear.


I had the front panels spray lacquered by a professional and gluing lacquered panels take special precautions as the the lacquer is very fragile.
Make blocks of MDF fitting into drivers' rebates and insert the port, which will make another point of adding pressure. For the bottom end I used some plastic wrap material and a large piece of MDF to spread out the pressure. For gluing the front panels I used Superfix. Leave the clamps for 4-6 hours before removing. Superfix settles slowly compared to standard PVA glue but will retain some elastic properties decoupling the front panel slightly from the cabinet.

CABINET DAMPING


Use 8 mm felt material and 30 mm polyester fill supplied with the crossover kit.

Cut the following pieces:
4 x 640 x 28 = 71680 sqcm (sides)
8 x 160 x 28 = 35840 sqcm (top-bottom)
2 x 640 x 14 = 17920 sqcm (rear panel)
total 125540 sqcm = 1.25 sqm, 1.3 sqm supplied.

Ad 8 mm felt to all internal surfaces except front panel. Ad two layers to top and bottom.
Cut 5 pieces of ~18 x 30 cm polyester fill and place 2 sheets at top and bottom. Place one sheet on rear panel behind 18WU driver. That's all.