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<blockquote data-quote="newusername" data-source="post: 2128424" data-attributes="member: 562064">Here&#039;s a wrench for ya....Driver A may be 3 dB more &quot;sensitive&quot; or &quot;efficient&quot; at a particular frequency than Driver B with 1W or 2.83V or however you wish to rate it.But what happens at 100W as excursion increases?&nbsp; What happens when Driver A suffers from thermal power compression, Re doubles causing Qes and Qts to double with it?&nbsp; What happens when driver A starts to move out of the gap and BL drops, causing further changes to Qes/Qts and causing BL based distortion?&nbsp; What happens when Cms changes?&nbsp; Power compression (be it Re, BL, or Cms based) is a real problem and throws these efficiency ratings out the window.Keep in mind that the only parameters that truly matter are Re, BL, Cms, Mms, and Sd.&nbsp; Every other parameter is drawn from these 5 basic parameters.&nbsp; The big issue with the use of t/s parameters (whether it is with people online or through simulation) is that there is a wide spread lack of understanding how these interact in a real world application with large signal applications.Sensitivity and efficiency tell you very, very little other than what happens at whatever power level they rate it at, and includes absolutely NOTHING about the enclosure; for EVERY subwoofer, the enclosure plays a larger factor in efficiency and any excursion at a given frequency.Loyd and Jim could not be more correct.Cheers,Neil</blockquote>

[QUOTE="newusername, post: 2128424, member: 562064"] Here's a wrench for ya.... Driver A may be 3 dB more "sensitive" or "efficient" at a particular frequency than Driver B with 1W or 2.83V or however you wish to rate it. But what happens at 100W as excursion increases? What happens when Driver A suffers from thermal power compression, Re doubles causing Qes and Qts to double with it? What happens when driver A starts to move out of the gap and BL drops, causing further changes to Qes/Qts and causing BL based distortion? What happens when Cms changes? Power compression (be it Re, BL, or Cms based) is a real problem and throws these efficiency ratings out the window. Keep in mind that the only parameters that truly matter are Re, BL, Cms, Mms, and Sd. Every other parameter is drawn from these 5 basic parameters. The big issue with the use of t/s parameters (whether it is with people online or through simulation) is that there is a wide spread lack of understanding how these interact in a real world application with large signal applications. Sensitivity and efficiency tell you very, very little other than what happens at whatever power level they rate it at, and includes absolutely NOTHING about the enclosure; for EVERY subwoofer, the enclosure plays a larger factor in efficiency and any excursion at a given frequency. Loyd and Jim could not be more correct. Cheers, Neil [/QUOTE]

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