Speaker grill material, any real difference?

Fabric material for speaker grilles usually doesn't cost much. As suggested by Mike60, perhaps the speaker manufacturer might be able to help if you really need to get the grilles fixed.

All Hail Jsd52756 on his arrival to the DARK SIDE...
'Never spend less than you can on audio'...it's so written in the stars.
My foray into audio changed my entire life.

Seriously...Single strand, double knit polyester is probably perfect. Most cloth stores offer it.
It's acoustically transparent and easy to work with and, cheap.

Larry

There is no cloth that is acoustically transparent. Use your brain. ANYTHING that is placed in front of a transducer, WILL(in one way/degree or another)have an effect on the sound radiated. Some speaker systems are tuned for their grille cloths, but that is rare. That's why most systems sound better, with the grilles removed.

Granted anything will affect the sound, I like the way they sound with the grills on. Actually the manual states to leave them on as well. I think since these speakers have both planer type and cone type drivers the cover helpes blend the sound properly... Maybe?
"Single strand double knit polyester?" Sounds like one of my old disco shirts. I'll check it out, as well as the standard issue stuff.
-JD

Speaker designers final voice their speakers with the grills on....therefore, the fabric will make a difference. Take a sample of original grill material to your fabric store and ask for a duplicate material with similar weave.