How grills affect?

I, too, have Dunlavy V's and they sound more transparent with grills of,(measures flater too, +/-2 db)eventhough the manual says they are designed to be listened with grills on.

Back again. I did a late night listening comparison with my Thiel CS1.5s. Since I had to keep the volume down, I can't say much about the anti-diffraction properties of the grilles. (I'm really not sure I could ever evaluate those properties.) However, the speakers did sound better to me with the grilles off, more detail and spatial cues. I took a close look at the 1.5 and 2.3 grilles. I put them against a light and also did the "breath test." They look like they could have been designed better. It seems there could have been less grille material and more space for airflow. When blowing into the grilles, there is a good bit of resistance to airflow. I can't imagine that these grilles could possibly be "acoustically transparent." I suppose that more acoustically transparent grilles become less effective as dust covers and visual blocks.

First things to go on my SCiv's were the grilles. Sound much better when the grilles are in the closet than when they are masking the speakers. Tom

Bufus, I don't believe the 1.5 grilles were meant to be acoustically transparent. I think that's what the manual means about their anti-diffraction properties.

Good thought Leoturetsky. I was only thinking about the rounded edges for anti-diffraction. I suppose the grille material could also be part of the scheme.