According to Owens-corning a 2" thick 703 rigid fiberglass panel absorbs 0.17 at 125hz. But a 4" thick 703 absorbs 0.84. So would two 2" pieces put together yield 0.84 also, or only 0.34??
Stacking 703
Originally posted at johnlsayers.com, topic 9188.
Torture,
2 slabs combined (2 x 1/2 thickness) together will respond (+/-) the same as a slab of the total thickness (1x 1/1 thickness).
Hence this 0.84, not this 0.34