The only bad thing about ported enclosures is that they unload the woofer below the tuned frequency. This can have profound and damaging effects to the woofer. This can happen even though you are well below the woofers power rating. Which brings up another side of the story. There are really 2 kinds of power ratings for a woofer. The one stamped on the bottom of the magnet is the thermal power rating. This simply means how many watts the coil can handle before it melts. The other is far more critical, IMO. It is known as displacement power handling. It is 99% controled by the enclosure. Enclosures such as a poorly tuned ported enclosure will have a much smaller displacement power handeling than thermal. About the best for displacement power is a properly designed bandpass. Typically a 4th order, or single reflex. These IMO are the best enclosures for true sub bass. Excellent displacement power handeling and typically a 3 to 6 db gain (even better than ported) in the sub bass region.I'm not saying sealed enclosures are BAD, but rather not nearly as efficient as a ported enclosure. No matter what application, a sealed enclosure is not as efficient as a ported enclosure. Why? That port is another source of sound waves. This can effectively give a 3 dB of gain. This is quite noticeable. Not to mention, you have a MUCH better frequency response with a ported enclosure over a sealed. AND, because you have full power handling down to the tuned frequency, this gives you cone control into the lower frequencies. This will allow you to put more power to lower bass and keep the cone controlled, unlike a sealed, where the cone excursion just inceases as the frequency decreases.