Hey JLM,I was sure from listening to others that these would degrade my sound, but it's fine. I can detect no difference, but then 1600Hz is a pretty long wave to have a problem with 1/2 inch sized holes a couple of inches in front of a cone.
Check Garlands speakers to see an interresting spin on the traditional cloth grill.
http://dsb.8m.com/pipics/pipics.htm
and my site if yer interrested.
Thomas