I've seen on different site and forums that people often suggest the use of a sub equalizer with a sealed sub but I've seen it less often with ported sub. eD even offer a reduction on their equalizer when you buy a sealed sub but not when you buy a ported one. My question is simple: why?

Thanks

Sebastian, I haven't noted either of the points that you mention. The need for equalization depends on the room and the location of the sub within it, but shouldn't vary significantly depending on whether the sub is closed or ported. A closed sub rolls off more gently(12dB per octave)below its tuned frequency than does a ported sub(24dB per octave), but both are subject to the effects of room modes.

As to the eD equalizer, I recall reading that a lower price was offered in a package deal with their subs, but there was no indication that this depended on whether a closed or ported sub was bought(which would appear to make no sense).