open cell foam for entec subwoofer grill

Wondering if anyone knows where to buy some black 1' X 2' by 3/4" thick foam grill covers for my Entec LF 20 subwoofers- my foam has deteriorated and can't find anything in audio places i've checked with or in local homedepot, lowes etc-
I would construct a sturdy frame the same size and shape as your failing foam grill, then cover it with acoustically transparent black cloth.

The original foam will probably be difficult to find and probably offers no advantage musically.
The Entec grill material is completely transparent (and ugly).
I believe Wilson Audio used the same material on the Watt 3/Puppy 2.
Contact Crosby Audio Works for replacement grills.