It depends if the grill was an after thought by the designer or if like on Vandersteens it was part of the design. It is not the shear Fabric we hear but the diffraction caused by most grill frames. Vandersteen speaakers use the grill and frames to smooth the transistion from the driver edges and the enclosure.
Without them large peaks and dips + - 6 DB can be heard and measured. If in dought call the manufacture and ask if the speakers were designed with the grills on or off. Look at the pictures of show reports and see if the manufactures showed with them or without.
Without them large peaks and dips + - 6 DB can be heard and measured. If in dought call the manufacture and ask if the speakers were designed with the grills on or off. Look at the pictures of show reports and see if the manufactures showed with them or without.