Here are some progress photos of the CommonSense Audio Monitor MkII bass reflex speaker enclosure that I am putting together to be used with the
Audio Nirvana Classic 8 full range speaker driver.
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Birch-Plywood-for-Speaker-Box.jpg
The plywood is 3/4 inch (19 mm) thick multiplex (11 ply) birch. The price is $40 (Canadian) per 4' x 8' (1.2 x 2.4 m) sheet (purchased from Rona). The birch plywood is fairly void free, but the outer veneers are virtually paper thin. This birch plywood is not the superior quality of a true Baltic birch plywood, but it is good quality and a very good value at this price.
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Butt-Joint-Birch-Plywood-Speaker-Box.jpg
To construct the bass reflex speaker enclosure, the plywood pieces were simply butted together, glued and well clamped.
Attachment:
Gluing-Birch-Plywood-Speaker-Box.jpg
For the damping material an R12 insulation was used and is held in place using 12 mm staples at about 4 inch spacing. This seems like it will work really well as an acoustic dampening material.
Attachment:
Acoustic-Insulation-Bass-Reflex-Speaker-Box.jpg
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Acoustic-Insulation-Bass-Reflex-Speaker-Box-2.jpg
And gluing the final piece of birch plywood to finish up the bass reflex speaker box.
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Final-Gluing-Birch-Plywood-Speaker-Box.jpg
I was pretty happy with the end result of the speaker box. There was a little excess to trim off with a flush trim router bit on one end. The speaker ports have a very small roundover. T-nuts are used for the driver.
Attachment:
Birch-Plywood-Bass-Reflex-Speaker-Boxes.jpg
For the finish I am planning on using a dark "Ebony" Minwax oil stain. I am thinking a dark finish will help to hide the plywood laminations on the edges. Before staining I'll apply Minwax prestain wood conditioner to prevent blotching. Two coats of ebony stain. Then I buff with ultra fine steel wool #0000. To finish I am thinking a coat of a polyurethane. I should get that done this weekend and I'll post photos.
Cheers