John,
For the money, you can not beat the cost/performance in moving up to the 15" from Adire or Stryke.
If you plan on using the Adire driver, I do suggest you download the Adire LspCAD. As Dan stated, LspCAD is one of the most powerful loudspeaker tools available. LspCAD for me and others has been very accurate with the numbers. For example, some are doing 1m measurements and the frequecy lines are practically identical. Of course this is provided how much correct data you put into the software.
There's Unibox, which is freeware, IMHO, it's better then WinISD.
Also, my old MASS/SHIVA sub and Terry/Rich MASS Sub are "Water Heaters".
JD.
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