Sensitivity and Volume

[hajame]

I found some low sensitivity speakers(80 to 86dB)sounds much better at higher volume. It seems to be a threshold volume for this type of speakers to sound right. At low volume, the tonal balance is usually no good. Examples are ATC passive monitors and my pioneer S-A4SPT-PM. Higher sensitivity speakers such as proac, elac and many full-range one sound right even at low volume. Is this their inborn characteristic?

[BlueWizard]

Well, this will be my very un-expert opinion.

First question, what do you mean by 'higher volume'? Is this perceived volume, measured volume (per spl meter), or volume as judge by a certain amount of a turn of the volume control?

Big high efficiency speakers are always moving a lot of air and moving it well regardless of the volume (within reason, of course).

Smaller less efficient speaker really don't move air that much air or move it that well. When you really crank them up, naturally they are pumping air harder which might account for their sounding better.


Having said that, efficiency is about just that efficiency; about how much acoustical power we get out for how much electrical power we put in. But, in and of itself, it has nothing to do with quality.

High efficiency speakers can sound like doggy-doo, and low efficiency speaker can be smooth as silk; or it can be completely the other way around.

Also, I suspect low efficiency is related to both cone and box (air) stiffness. At low levels you aren't doing enough to overcome this stiffness. The resistance of the cone and the cabinet are overwhelming (somewhat metaphorically) the applied power. Once you start cranking, you are pushing enough power into them to physically overcome the stiffness of the cones or the stiffness of the air in the cabinet.

But then, that's just a guess.

Steve/bluewizard

[mashaffer]

Just a guess but it may be (partly) that when the inefficient speakers are pushed hard that there may be an asymmetric compression that increases second harmonic content and thus mask other naughties. Just a suggestion to consider as I have no data on the matter.

mike

[GM]

Originally posted by BlueWizard

Also, I suspect low efficiency is related to both cone and box (air) stiffness. At low levels you aren't doing enough to overcome this stiffness. The resistance of the cone and the cabinet are overwhelming (somewhat metaphorically) the applied power. Once you start cranking, you are pushing enough power into them to physically overcome the stiffness of the cones or the stiffness of the air in the cabinet.

Close, 'sounds' like the LF/mid-bass drivers are low Vas (low compliance), the bane of efficiency, which requires more power to overcome both the suspension's 'stiction' (for lack of a better word at the moment) as well as the small box compliance it requires, so they lag behind the mids/HF until they're sufficiently 'motivated' . Such systems are in serious need of a variable bass boost (aka loudness control once common on amps, receivers) to allow a wide range of tonally balanced average SPL.

GM