Basic question about sensitivity


Obviously I am mistaken, and I am positive that this has been covered before,  but I had thought that the higher the number (sensitivity) the easier the speaker was to drive.  However, when I read a thread in which someone is talking about a speaker they have or are interested in, I frequently do a cursory search and a little bit of reading about it, and, for example, a while ago I read a review & specs on the Monitor Audio Gold 300 5G with a sensitivity rating of either 90 or 91 (which I would have thought at one time meant it was a pretty easy load to drive) but the recommended amp was 100 to 250 wpc.

On the other hand, I just did a search and some reading on the Harbeth P3ESR XD which has a sensitivity rating of 83 (which at one time I would have thought meant it was a tough load to drive) but they are recommending amps "from 15 wpc".

What is the number listed for a speakers sensitivity actually meaning?

 

immatthewj

It simply means that at one watt of power a speaker will produce the given amount of decibels. A flea watt amp will drive those Harbeth’s just fine, but it may not get loud enough to work in larger rooms.

@yoyoyaya  It is a good measurement except :

  1. It is not universally available.  We only know about the from what they chose to review
  2. It is not easy to calculate from normally published specifications.

Since manufacturers do not publish EPDR we are stuck trying to identify hard to drive speakers without it.  Often we can't even get minimum impedance values either.

@erik_squires - not disagreeing, but at least Stereophile and Hi Fi News are trying to be as informative as possible. But what the EPDR measurements of a range of speakers do tell us is that, in general, speakers are harder to drive than most manufacturers' generally used specifications tell us. So my rule of thumb is to take the nominal impedance and assume that the real impedance is lower than that.