Black felt with adhesive on one side that sticks to tweeter face plate. The diffraction ring can help stop the initial reflection from the tweeter dome off of the cabinet face.
People find them useful to cover an aftermarket tweeter that may not fit perfectly like the original, like using a round tweeter to replace a square one.
At $2.00 a piece or
$4.00 a pair these rings really make a difference,if you don't believe it, do one speaker 1st. and listen,switch cables ect...
It is not a huge difference but a nice subtle one,the top end becomes a little smoother and details are cleaner with less edge to them,the off axis response
way improved.
Give these a try, You won't remove them,and they are only the price of a cup of coffee.
