Oh yeah, in a large box size like 8 or 12 cu.ft., the difference in thickness of the 'glass will be a much smaller amount compared to the overall enclosure volume...I would imagine the tuning change would be much less noticeable, but the difference in sound absorbtion damping internally may be audible in the midrange. I like the walls adjacent to the woofer to be well 'glassed, seems that less bounce back thru the cone by the rear wave occurs, resulting in a slightly cleaner sounding presentation.