Good speakers less efficient?

That's a good point Bartok.

Most mid-range to large models from manufacturers such as Merlin, Altec, Klipsch, Zu, Avantgarde, Cain and Cain, Silverline, Acoustic Zen, Gallo, Wharfdale, Coincident, Tannoy, Fostex, Oris, Duevel, Green Mountain Audio, Maxxhorn, Devore, etc. really do suck most amps dry.

Thanks.

Duke,

Thanks, I am sure you are right about the causes or shifting tonal balance (from different driver sensitivities). My experience is probably not representative as it does not involve more than a few dozen designs.

However there is another angle. The Fletcher-Munson equal loudness curves. These also have impact on the perception of sound at various levels;

130 db at 20Hz sounds as loud as 100 db at 2 Khz.
110 db at 20Hz sounds as loud as 60 db at 2 Khz.

Notice that this implies that our ears compress the mid range relative to the bass as you go to higher SPL's (a 20 db increase in ultra LF requires a massive 40 db increase in mid range to maintain equal terms of loudness perception)

I guess this explains why rock mixes that are designed to play loud are usually mixed thin in the bass. It implies that to maintain consistency to our ears at various sound levels then the bass should be compressed as you increase SPL in order not to have too much shift in the balance.

Does this imply that relative compression between drivers might actually be desirable in a speaker?

Does this imply that there is fundamentally a SPL sweetspot for particular forms of music that is independent of the speaker used?

Thanks for your insights.

Shadorne says.... "Does this imply that there is fundamentally a SPL sweetspot for particular forms of music that is independent of the speaker used?"

Of course. Just yesterday I listened to my CD of Kings College Chior Christmas Carols, and with all those voices, and the organ thundering away, I got to thinking about why I have six large subwoofer drivers. No way that music would sound right coming out of a 6 inch bookshelf speaker. On the other hand, I have violin recordings that must the played at a much lower SPL. A real violin can play only so loud, and if you crank it up louder than that it sounds lousy.

I agree with Eldartford above in that I noticed there seems to be a level on a number of recordings that seem to "come to life" at a given point and then as it gets louder, the magic tends to go away.

On some recordings there are multiple "magic" SPL points (and I noticed that in a number of cases the other magic points seem to be a multiple of 3 db, give or take, from the initial magic point - go figure).

Sensitivity is the proper term. There's no correlation between high sensitivity and low sensitivity as it relates to quality. Only the speaker designers idea of what works best.

You'll also note most speakers are 86 to 92db sensitive. I'd guess that may cover 90%.