In my last post you may recall that I talked about replacing the old insulation in my PBM-8 studio speakers. The reason for wanting to replace these speakers have a tuned port. Now, if you know speakers, you already know that a tuned port is a small tube in the back of the speaker cabinet. I am not real good with the physics of the system, but this radically improves the acoustics of the cabinet. Unfortunately, it is also the foyer to a mouse home.
While exploring one of the local big box hobby and craft stores I discovered a product called “NuFoam”. This is a fascinating polyester product that is available in sheets. It is described as “densified polyester padding”.
The photo on the right shows the inside of a speaker cabinet with the sides and bottom foam installed. The back piece is not in so you can see the tuned port in the lower left corner and the crossover in the center.
Cutting the NuFoam is fairly easy. I used a good pair of scissors. With careful measuring the job was pretty easy. 3M 45 spray glue holds the foam in place “just in case”. A quick shot does the job, there is no reason to coat the entire side or piece of foam.
This next photograph shows the interior of the speaker cabinet with the foam lining fully installed. It looks rather nice, if I do say so myself, and I am confident that it will work, acoustically speaking, the way that we want it to.