Butyl surrounds for 6" or 8" woofers
(Note: these are not available as a separate part.)

I make available as an option on my six and eight inch woofers the use of butyl rubber surrounds.

There are several reasons for this. One is that some people perceive the rubber as a more durable material than the foam used on many speakers. Another is that some of the earliest EPI speakers used butyl surrounds and their owners might prefer to use the "stock" material on their replacement parts.

As I see it, there are advantages and disadvantages to the rubber. The decision, of course, will be up to you, whether you are buying EPI or Genesis replacement parts or drivers for a D.I.Y. project.

Advantages: As I already mentioned, the butyl does not tend to slowly degrade with time, like foam surrounds (which eventually turn into dust after twelve to twenty years of service). This can be considered to be a much more important factor in automobile speakers, since they are exposed to a harsher environment which can severely shorten the life of foam surrounds. Of course, the speakers will then probably outlast the vehicle!

Disadvantages: Well, they do cost more. Also, with age, while the butyl does not "fall apart," it will slowly harden and stiffen. This will change how the woofer sounds. Eventually the rubber will start to crack and need repair, although this can take quite a bit longer than the foam takes to disintegrate. There is also the factor of weight - the butyl surround weighs almost as much as the entire foam surround and paper cone assembly, and this will introduce subtle changes in the way the speaker sounds, by altering the resonant frequency, and by reflecting some energy back into the cone material.

As I said, the decision is up to you, and I will not question it. I just wanted to explain what the butyl surrounds are and why some people will want to use them.

To return to your reading, please use your browsers "back" button, use the drop down menus at the top of this file, or select a top level menu link below.