Though this is straying a bit from the topic at hand, I must point out that quality speakers employ a range of designs, from simple sealed designs, to the ported designs you mention, on up to folded or full-scale (built with cinder block walls[0]) subwoofer horns.
The purpose of the port in ported designs is not just to allow movement of air, but to control the resonant frequency and Q-factor of the speaker. The individual dimensions, size, shape, and materials of quality speaker enclosures are all tuned to control resonance.
To sum up, there's a lot more to it than "an airhole to allow movement of air."
The purpose of the port in ported designs is not just to allow movement of air, but to control the resonant frequency and Q-factor of the speaker. The individual dimensions, size, shape, and materials of quality speaker enclosures are all tuned to control resonance.
To sum up, there's a lot more to it than "an airhole to allow movement of air."
[0] I can't find the actual system I recall, but here is an older system with a similar design: http://www.burwenaudio.com/images/20000_WATT_HOME_HI-FI_0476...