I've been thinking about thin-wall enclosures that the BBC pioneered and I wonder - does it need to be ported to work right?\r\n\r\nMost of the BBC designs were ported, and at first thought it seems it would be necessary to prevent the thin wall enclosure from being internally pressurized and flexed excessively. However, a port actually only operates as an open 'hole' to sound below its tuning frequency. At or above its tuned frequency it has a high acoustic impedance and is seen by the woofer pretty much as a closed box. So in such a speaker with a 50Hz tuned port, at 100Hz the enclosure will still be pressurized regardless. Does that seem right?\r\n\r\nIf this is indeed the case then it makes one wonder if it really matters that the cabinet is ported since it would only reduce flexing of the walls at very low frequencies. Maybe that matters though?\r\n\r\nComments and thoughts?