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<blockquote data-quote="Electrodynamic" data-source="post: 6695024" data-attributes="member: 548723">I never said the Alpha was unable to move out of the gap and maintain a minimum 70% BL loss. If RD is rating their Xmax by typical overhang, that is their rating. I was unable to find any data that would say otherwise. I haven&#039;t seen any FEA or Klippel data that would support the notion of the drivers having more linear excursion than what they are claiming. I was going off of data supplied by both manufacturers, nothing more.If you added Xmax without verification to either driver, then you would be correct that the displacement values would change. But if you&#039;re doing that, why not pad other data as well? Calculating linear displacement is pretty easy: convert all measurements to one common value (in this case, I converted to cm) and take cone area and multiply that times linear stroke.For the Alpha, 490 cm^2 is a typical Sd for a 12&quot; driver that does not have a wide surround. Xmax is rated at 16mm according to RD&#039;s web page. Xmax is in mm, and in order to convert it to cm, 1 millimeter = 0.1 centimeters, which makes linear excursion 1.6 cm. Multiply the surface area of 490 cm^2 times the linear stroke of 1.6 cm and you get 784 cm^3 of linear displacement for a single driver, or 1568 cm^3 for a pair.</blockquote>

[QUOTE="Electrodynamic, post: 6695024, member: 548723"] I never said the Alpha was unable to move out of the gap and maintain a minimum 70% BL loss. If RD is rating their Xmax by typical overhang, that is their rating. I was unable to find any data that would say otherwise. I haven't seen any FEA or Klippel data that would support the notion of the drivers having more linear excursion than what they are claiming. I was going off of data supplied by both manufacturers, nothing more. If you added Xmax without verification to either driver, then you would be correct that the displacement values would change. But if you're doing that, why not pad other data as well? Calculating linear displacement is pretty easy: convert all measurements to one common value (in this case, I converted to cm) and take cone area and multiply that times linear stroke. For the Alpha, 490 cm^2 is a typical Sd for a 12" driver that does not have a wide surround. Xmax is rated at 16mm according to RD's web page. Xmax is in mm, and in order to convert it to cm, 1 millimeter = 0.1 centimeters, which makes linear excursion 1.6 cm. Multiply the surface area of 490 cm^2 times the linear stroke of 1.6 cm and you get 784 cm^3 of linear displacement for a single driver, or 1568 cm^3 for a pair. [/QUOTE]

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