Because the sub was so tall, Boxnotes was used to look at the resonances that might cause problems

As shown in red on this screenshot, the vertical resonances would cause the most grief if left untreated.

To limit the effect of these resonances, foam rubber sheeting was placed inside the top and bottom surfaces, where pressure is greatest. After the back was glued on, two layers of acoustic wool were stapled across the middle of the box, where velocity is highest.

See the Gallery for more detail