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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8449 Registered: Dec-03 | <img=>http://www.diysubwoofers.org/graphics/driver1.gif</img> Excursion - ref. www.dictionary.com a. A movement from and back to a mean position or axis in an oscillating or alternating motion. b. The distance traversed in such a movement. * In regards to a loudspeaker, this refers to the distance the cone can travel back and forth within the limitations of the driver's suspension (spider and surround.) This distance, in combination with the surface area of the loudspeaker's cone, determines how much air is moved, mechanically speaking, by that speaker (not accounting for power requirements, cabin gain, enclosure effects, and other external factors.) which is why you see speaker diameter, along with excursion discussed so frequently by forum members, and the car audio community in general. The more air you move, generally the louder the speaker is going to get, all else being equal. (Which it never is.) Xmag = DUMAX Excursion limit due to the magnetic limitations of the driver's motor. Xmag is defined as the displacement at which the BL product has fallen to 70% of its value at the cone's rest position. Xmech = Maximum physical excursion capability of the driver. Exceeding Xmech normally results in damage to the driver. Xsus = DUMAX Excursion limit due to the driver's suspension. Xsus is defined as the point at which the compliance of the suspension has decreased to 25% of the value at the cone's rest position. Xmax = Linear (one-way) travel of the cone. Xmax is used to determine the maximum linear SPL capability of the driver, and can be defined in a number of ways. The DUMAX definition is objectively the best one, and it is defined as the shorter of the Xmag and Xsus values, in each direction of cone travel. This definition is more useful than the older definition of Xmax, which was solely dependent on the length of the voice-coil vs. the length of the gap. DUMAX = David Clark's DUMAX device is a driver measurement system that can, among other things, measure how far a driver's cone can travel while still working in a linear fashion. This gives a more consistant, and useful measurement for T/S specifications when looking at loudspeakers. Much like the new CEA ratings for amplifiers, DUMAX specs on loudspeakers level the playing field and give comparable results for products when comparing between different manufacturers, taking the "fudge factor" and hype, or misleading advertising tricks out of the equation. |
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america fu*k yeah! Unregistered guest | your mind amazes me... whats the xmax of a brahma 12 one way? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8464 Registered: Dec-03 | 28mm if I recall. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8542 Registered: Dec-03 | jsut in case you missed it the first time :D |
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grease dog Unregistered guest | i dont think they found it as exciting as the other word of the week. i think you should do efficiency on amps or sub or sumthing, test the cuspid and giver your honest opinion about the sub |
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jjjjjjj Unregistered guest | the new cerwin vegas strokerpro 15 have an excursion of 3 inches (rms 4,000- peak 5,000) |
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Gold Member Username: James1115Wilton, Ct Post Number: 3708 Registered: Dec-04 | good one glass that should clear up some issue's where people believe that because 1 sub has more xmax then the other it is louder. |