There are no grilles on my ESP speakers. The fabric covering is permament, so comparison is not possible. An obvious choice by the speaker designer to have you not listen without the fabric.
I prefer the appearance of my N802's with the grilles on and that's the way I listen. There is a difference (slight) between clothed and naked but I've become accustomed to the sound with the grilles on. Someone else may hear it the other way.
My Triad System 3 speakers are designed to be used with the grilles in place. The drivers are staggered in depth on the baffle and the grille provides the tweeter with a certain amount of controlled directivity. They don't sound right at all with the grilles removed.
So, my answer would be specially designed grilles are science and not snake oil. OTOH some grilles provide an enhanced appearance without undermining the performance of the speaker which I would also rate as good design.
I prefer the appearance of my N802's with the grilles on and that's the way I listen. There is a difference (slight) between clothed and naked but I've become accustomed to the sound with the grilles on. Someone else may hear it the other way.
My Triad System 3 speakers are designed to be used with the grilles in place. The drivers are staggered in depth on the baffle and the grille provides the tweeter with a certain amount of controlled directivity. They don't sound right at all with the grilles removed.
So, my answer would be specially designed grilles are science and not snake oil. OTOH some grilles provide an enhanced appearance without undermining the performance of the speaker which I would also rate as good design.