800watt, 12' long 16" diameter Bass Cannon.

Step 2 Cut the Sonotube into two pieces

Work begins by cutting the sonotube. The sub woofer mounting flanges need to meet 1/4 of the way down the length of the tube. For me and my 12' long piece thats 3' along.
Do do this accurately I measured with a large sqaure 3' from one of the ends at about 6 points around the circumference of the tube. I then wrapped a piece of masking tape around, making sure one edge of the tape passed through the points I'd just marked. I used this as a guide for the jigsaw. I drilled a starter hole to get the jig saw blade in then went at it! Afterwards I removed the tape. The cut will be kinda fury but that ok, this will be concealed inside the flanges.
I didnt take a photo of this step so I drew it. See the diagram with the light grey lines being my 3'
long marks then the dark band being the tape which i used as a guide to cut the tube squarely.

Comments

[tartanphotographic]

A simple method I have used to mark exactly around the circumference of a cylinder is with a piece of paper longer than the circumference and at least 2" wide. Wrap around column and match up the nice straight, factory edge. Tape the strip together and either draw line against paper edge or spray paint the edge.