Speaker sensitivity vs SQ


My first thread at AG.

Millercarbon continues to bleat on about the benefits of high sensitivity speakers in not requiring big amplifier watts.
After all, it's true big amplifiers cost big money.  If there were no other factors, he would of course be quite right.

So there must be other factors.  Why don't all speaker manufacturers build exclusively high sensitivity speakers?
In a simple world it ought to be a no-brainer for them to maximise their sales revenue by appealing to a wider market.

But many don't.  And in their specs most are prepared to over-estimate the sensitivity of their speakers, by up to 3-4dB in many cases, in order to encourage purchasers.  Why do they do it?

There must be a problem.  The one that comes to mind is sound quality.  It may be that high sensitivity speakers have inherently poorer sound quality than low sensitivity speakers.  It may be they are more difficult to engineer for high SQ.  There may be aspects of SQ they don't do well.

So what is it please?

128x128clearthinker
I'd go with mahgister.

AR 18s speakers (88dB) driven by a Rotel RA-414 amplifier (35W) can rock the place with 50-60 people whole night long and like that every weekend for years.

How much easier to drive you need them to be? I am sure there are armchair theories, but in real-use practice that is all one may need.

Skipping humongous speakers (Moabs anyone?) leaves more space to cram another few people in the room.
I agree that speaker manufacturers don't, but should, publish their impedance graphs.

However, I also believe that there are a plethora of amplifiers that can power most, except for the ridiculously low impedance speakers, and they sell for reasonable prices nowadays, particularly if purchasing used.

Thiel speakers and other hard to drive speakers are still as popular as ever.  Thiel owners seem to find amps that make them sing and they love their speakers.
There is an inevitable tradeoff relationship between box size, bass extension, and efficiency. And it’s a fairly brutal relationship.

If you keep the same bass response, every 3 dB increase in efficiency calls for a DOUBLING of box size.

So compared with a 1/2 cubic foot 85 dB mini-monitor that goes down to 40 Hz, a 97 dB efficient speaker with the same bass response would be SIXTEEN times the size (four doublings of box volume), or EIGHT cubic feet.

Now imo there are definitely some qualitative advantages to that higher efficiency, but in my experience the market for eight cubic foot speakers is rather limited.

Anyway my guess is that the higher costs and the box size penalties attached to high efficiency are the primary reason why low efficiency speakers dominate the marketplace.

Duke


@ clearthinker
An excellent first post. As you can see by Duke’s response above you are correct, there are other factors that are impacted by and to be considered when evaluating a speaker’s efficiency.

MC’s response to your thread is somewhat puzzling, you do seem to "get it".
Encouraging to see at least some get it. Not surprised at all to see the O P does not.
There is an inevitable tradeoff relationship between box size, bass extension, and efficiency. And it’s a fairly brutal relationship.
This observation nail the question with the beginning of an answer...