My Miniwaves are a budget test of the waveguide approach to speakers, including a 6" Vifa midrange and B&C compression driver loaded into an oblate spheroid waveguide. Previously I tried a foam mod with dacron, with little success.
More about the Miniwaves
In a recent waveguide shootout, they had the least amount of horn harshness.
I've found that reticulated foam takes waveguides to another level, hence this mod shown here.
First I created a template. I then cut the foam using the soldering iron. The result is shown below.
You can see I've tried cutting the foam differently on the outside.Where to get reticulated foam in Australia