Felt diffraction reduction advise


Never heard or tried them. Would try them on soft dome tweeters on floor stand or monitors. I have no problem with way system sounds now. Just found black wool felt in a Christmas box. Always been curious of speakers with felt with different cut out patterns. What inch thickness and pattern do I need to achieve any results good or bad? What will I hear when doing this?
paulcreed
Vandersteen's is deep enough to act like a bit of a waveguide.

And yes, it does help. The felt seems to reduce re-radiation directly around the tweeter enhancing the speaker's disappearing act.
I have a question. If the creator of the speaker thought it needed felt, wouldn’t he or she have included it? It’s cheap and easy to apply. Or would it be added to change the highs in a unique situation?
Cut a couple pieces to match outside size of tweeter and perfect round cut to go around dome fairly close noticed slight change in sound stage. Then made another to stack that's when I notice loss of sparkle. Using blue tak so I can install and remove quickly for now. Maybe there is something to cut out being rectangle or star pattern, or stepping each layer with larger cut out like a horn. Does it matter how close felt is to button of tweeter? I'm going to just try strips for a square pattern and see what happens. I agree if there is a benefit why don't speaker manufactures use this, maybe cause it's ugly, if it works I don't care.