Permanently sealing a vented subwoofer??

Calm down there Doc

Drew, please contact the engineering departments at B&W, Avalon, Monitor Audio, Proac, Spendor, Eggleston, Wilson, Sonus Faber, VMPS, Harbeth, et. al. and let them know about the problems with their "cheap" and "small" designs.

A properly designed sealed enclosure or acoustic suspension subwoofer will exhibit superior transient capabilities or known as faster group delay response. There are always trade offs and sealed enclosure type subwoofer requires more robust drivers and a whole lot more amplification power. Read latest Absolute Sound article on subwoofer and review on JL Audio Fathom F113 subs and also do google search on Adire Group Delay. For music systems, I like sealed subwoofer designs. For non critical low frequency effect of home theater one note type sub sound there are pleny of ported or passive radiator subs available - Velodyne, Earthquake, Hsu, Sunfire, to name a few. But if you want quality sealed enclosure type subwoofer that can keep up with transient capabilities of your main speakers check out subs like JM Labs Sub Utopia, Focal BE 1000 sub, JL Audio Fathom F113, Zu Method, Martin Logan Descent for starters.