@Charlie: My assumption (I don't actually know) is that the small block near the tip is a double tweeter. (You can see what appears to be two distinct units). There is then a large block consisting of dual mids as well as a woofer, with the woofer approximately the same size as the combined dual mids. Westone`s claim, as quoted from a previous post in this thread, is that the single woofer is large - larger than each woofer in a multiple array - which allows for good bass quality. The bass is very well controlled IMHO.
Edited by cooperpwc - 8/24/10 at 7:50am