Yes, this is normal. Grills cause diffraction and frequency response abberations. Joe D'Appolito has said that he never met a grill that he liked. Now you know why : ) Sean
My grills sit in a cupboard...they sound better there...lol...seriously though...I feel the same way...no grills sounds better than keeping them on. Uh-oh...we might be letting the cat out of the bag...now speaker manufacturers may start offering grills as options...I can't have that...what would I put in my cupboards?
Because of their sonic degrading character, speaker grills also work well at distorting your voice when used as a mask during bank robberies.
I always felt guilty when using my girlfriend's pantyhose for heists. In the event I was nabbed, with the DNA evidence recovered from the make-shift mask they'd be able to trace the hose back to her, and she'd get in trouble too.
"We want to hurt no one. We're here for the bank's money, not your money. Your money is insured by the federal government, you're not gonna lose a dime. Think of your families, don't risk your life. Don't try and be a hero."
Depends on the grill material. Also, it depends on the speaker configuration. My planar speakers, MG1.6, have woven grill cloth that is very transparent, but besides that the planar diaphram movement is so small and the audio pressures so small that I don't think the grill cloth has any effect. With cone speakers, it is usual to see the grill cloth vibrating in front of the woofer, and that vibration cannot happen without soaking some energy out of the audio.