aznboi3644 wrote on 05/23/07 at 20:37:56:yeah but sub displacement is not enough to make a noticeable difference unless the sub has a HUGE magnet and basket
Don't make me do math, today, please. When you have a huge enclossure, I agree, the speaker displacement is insignificant in the real world. When you have a sealed chamber that is only a couple of cubic feet, the difference between subtracting the driver displacement and adding the driver displacement becomes more noticeable. It seems to me that when I increased the sealed chamber by two basket volumes (the difference between the driver mounted one way compared to mounting it the other way) it made a significant difference in the lower range of response.
Whether the octave above 100Hertz is easier to hear, with the air pressure slinking around the magnet or not, becomes less significant than the actual volumes involved. I'm talking about a listening test for seat-of-the-pants feel plus some perfunctory measurements using a cheap Radio Shack decibel meter. I don't know which box tuning program someone could use to model the Wicked One, though.
Also, don't forget the diameter of the cut-out times the 1.5 inches you gain by mounting the driver completely inside the vented chamber. It makes a difference, because the volumes we are dealing with are small, or at least similar to the driver Vas. Taking your statement to the logical conclusion would lead us to thinking that the volumes are insignificant, in total. We would not need to measure anything.