How grills affect?

I have to agree with Bufus my Thiel 2.3’s to a very very small degree change the sound. Jon Risch has done some research on acoustically transparent materials for his DIY panels and has found that burlap to be the most transparent.

Burlap for speaker grilles- Perish the thought.

I've had the Forests for almost two years now. Couldn't imagine leaving them alone with the kids without the grills on. Nice that Totem puts the rigid mesh guard on the tweeters, huh? I also remove the grills for most critical listening, and have noticed a larger change in dispersion than anything else. The way Totem closely matched the opening and drivers (one opening, but really kinda teardrop-shaped once the tweeter and woofer circular cut-outs are joined),sound seems to beam a bit more with the grills in place. Effect is that of the drivers being recessed 3/4" into the baffle face. "Problem" is with the grill frame only. I have no doubt the fabric is fully transparent. Love the speaks though.Drive em with Stratos monos. Gotta get a real pre though.

Sugarbrie is correct re: B&W Nautilus. Per the N803/N804 owner's manual: "For the most discerning listening, remove the cloth covered grille as described below in the section "Aftercare"."

The protective grille over the tweeter, on the other hand, should never be removed per the instructions.

Different Manufactures recommend differently. VMPS actually recommends removing the grills for critical listening. I don't know about you, but to me, all listening is critical. I have no children so I usually always leave the grills off. Besides, It's more enjoyable to look at the speakers.

The frame of the grill is probably the most offensive to the energy flow from speaker into room. Have you noticed that the high end speakers are getting more and more into rounded off edges, narrower cabinets, while some even slope from front to back.

Notice the tweeters of say the B&W Nautilus 801. It mounts on top of the cabinet and is tear drop shaped. It ain't just for looks, folks.

It is a continuation of the mounting the speakers as flush with the surface of the cabinet as possible.

I believe the manufacturers have to supply grill cloths strictly for marketing pruposes.

Someone mentioned that Vandersteen recommends leaving them on. Have you ever seen a Vandersteen naked? They are really ugly. And for all their good qualities at a reasonable price, a faily major criticism is the frame around the speakers supporting the grill causing diffraction of the small speakers.