In Reply to: insulation thickness posted by replay on August 16, 2002 at 07:52:38:
like the 2.5 cu.ft. quasi-4 Pi Pro's, the enclosure tuning freq. went down to 47.6Hz.(too low) when the full thickness R19 was installed(about 3.5inches thick). Splitting that down to 1.75 inches thick brought the Fb to 50.8Hz. Empty box tuning was 53.9Hz., where I wanted to be for alignment per Pi program. Boxplot and my ears say leave the tuning at 50.8 where it is now, 'cause I am not shaving those port tubes down another darn 1/4 inch!!! SamOh 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.
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