speaker sensitivity dividing lines


What do you consider to be the dividing lines between low sensitivity, medium sensitivity and high sensitivity speakers ? Here are some thoughts on the subject and please keep in mind that i'm basing these spec's on the speaker being fed 1 watt @ 1 meter with the results averaged over a wide frequency bandwidth ( 100 Hz - 10 KHz). While this "somewhat" takes the impedance variance out of the equation due to using 1 watt rather than 2.83 volts, a speaker that is more sensitive may not be "easier" to drive due to high levels of reactance and / or impedance swings. As such, the lines between a "resistive 92 dB speaker" ( medium sensitivity ) and a "reactive 95 dB speaker" ( high sensitivity ) could be blurred in terms of why a big amp can't drive a more sensitive speaker but a smaller ( yet "beefier" ) amp can. Then again, that is a whole 'nother can of worms for another thread.

The reason that i bring this up is that we may all have slightly different ideas as to what is high / low sensitivity. In order to make conversations a little more easily understood and get to a point where we are all on the same page, coming to some type of mutual understanding as to what we are using as reference points might make things easier. I think that this would come in handy for such things as an "Audiogon FAQ's" type of section that will probably pop up sooner or later.

As such, these are the basic guidelines that i tend to follow when looking at speaker sensitivity with the above criteria taken into account. I'd like to hear from others as to what their "dividing lines" are and how we could come up with an "Audiogon reference" when discussing speakers & efficiency ratings.

83 db's and below = ultra low sensitivity

84 - 87 dB's = low sensitivity

88 - 92 dB's = medium sensitivity

93 - 97 dB's = high sensitivity

98 dB's and above = ultra high sensitivity

Obviously, these figures are somewhat random but you have to draw the line somewhere as far as "spec's" or "performance on paper" goes. Any and all comments / suggestions welcome. Sean
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sean

Showing 1 response by hackmaster

Sean makes an extremely important point - EMF is a crucial factor in amplifier-speaker interaction and it is often ignored.

When it comes down to it sensitivity is really not a very useful specification at all. Impedance, capacitance, and back EMF tell you much more. Impedance and capacitance are easily measured and graphed. Back EMF is not as straightforward but it's pretty easy to tell if a speaker is pumping it out in large amounts or not from listening tests. Because Back EMF feeds on itself, and the louder you play, the more you are generating, it's a really important factor in loudspeaker-amplifier matching.

For more info see an article we wrote:

http://www.symphonysound.com/articles/tubefriendly.html