Blue Box

This is a speaker cabinet made for a Celestion Alnico Blue speaker. It is a closed back design constructed from 18 mm plywood, glued and screwed. It is covered with carpet, cheap stuff from Maplin, glued on with PVA wood adhesive.

The speaker cloth is fitted to a wooden frame which is attached by screws from the inside.

Component Parts

The box started as an 8 * 4 feet sheet of plywood. Somewhat difficult to manage on your own, particularly when space is limited, nevertheless, I managed to chop it up into the requisite sizes using a combination of electric hand saw, table saw and planer. Here are the component pieces. They are accurate to about 1mm,




The overhead router, a home-made arrangement as you see, was used to cut the various rebates, also to cut out the speaker baffle hole. Note the unsophisticated circle cutting attachment - a piece of plywood with a 1/4 inch pin for the pivot. I cut the hole with a 1/4 inch spiral down-cutting bit to get clean edges I also cut from both sides.


Here it is, going together. Just like Mechano. Clearance holes and countersinks are drilled for the screws and the first three edges joined. The glue will dry overnight then I shall fit the back using 1 inch rails to all four sides.



Here is the finished article in front of an XK3 organ. The application of the cloth covering was less than perfect. You can see on the front, top, left corner that some glue has come through. I applied too much.

I love the sound it makes driven from by clean 10 watt valve amplifier from the archtop guitar. A younger member of the family says it has too much bass. Not for me! 

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