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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
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
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
- 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
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.
Use 8 mm felt material and 30 mm
polyester fill supplied with the crossover kit.
the following pieces:
640 x 28 = 71680 sqcm (sides)
8 x 160 x 28 = 35840 sqcm
2 x 640 x 14 = 17920 sqcm (rear panel)
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