Low-sensitivity speakers — What's special about them?

In home audio, they are not your friend when it comes to dispersion and low distortion.

This statement is false. Horns are well-known to have extremely low distortion if properly designed- the first paper I saw in this came from the 1950s when slide rules were how things are done. Nowadays people use computers to optimize the shape of the horn and get very good distortion figures as a result.


The second thing horns can do for you has to do with controlled directivity which they have and other speaker types do not. This allows you to minimize side wall reflections (which are interpreted by the ear as harshness due to their short delay times) if you so choose.


As a result you can get excellent imaging and depth with very low distortion easily rivaling the best ESLs.

The problem is if you put more than 20 Watt to your speakers voice coil you will get huge TD.
For me it is rule of thumb, if speakers can't be driven by 20 Watt amplifier their compression level cause me fatigue.

@atmasphere 
Agreed!

Thanks for linked article, @alexberger. In real-world scenarios with mostly passively configured, inefficient speakers - certainly approaching to some extent live acoustic (or amplified) levels - Thermal Distortion is an inescapable factor.

@lonemountain --

Focusing on efficiency as a measure of speaker technology or quality is like judging a passenger car based on miles per gallon.

That’s only assuming high efficiency has main priority regardless of other aspects and ultimately sonic outcome - a convenient position trying to make your own point, but hardly the bigger picture.

Low efficiency is a hindrance; never a trait, and as such has that to fight as well in addition to all other areas in speaker design. They’re the product initially of a desire and need for smaller size to cater to a commercial market, NOT because they were deemed better sounding (but of course marketing efforts made their best to sell the acoustic suspension principle as such).

High efficiency and large size as a foundation is giving acoustics their more proper due, but also moves the design, at least partially, into the realm of acoustic transformation. The most predominant enemy of horns it seems, except when they’re bad designs and too small, is passive cross-overs and too shallow slopes. Horns generally don’t like working outside of their "comfort zone" or design specifics here, something active configuration can more readily accommodate with steeper cut-offs compared to (the side effects of) complex passive filters.

So, a high efficiency design properly (and actively) configured is a win-win scenario from my chair, the only real drawback being - to whom it may concern - large size.

There are newer generations of horns that are much better no doubt.  But well known to have lower distortion?  That gem is not in my physics text book!  Maybe I should qualify my comments to apply to normal SPLs in  nearfield applications (home audio)?  Maybe that's what you mean, that at higher SPL horns can measure better?  Over long distances or high SPL I would think could be true, but I'm not sure.  But nearfield?   I very much doubt that horns beat direct radiators in the low distortion game.  Certainly isn't my direct experience in my years in the audio business.   One only needs look to what the best of the best speaker designers of the industry are using for their best nearfield designs- and only in very rare cases (the JBL M1 comes to mind) are horns used.  

Does this mean there aren't horn based systems that sound good?   I've heard some that were very impressive.  But if you want Tom Petty's guitar to sound exactly like the real thing in the studio or at home, off axis and on axis, at listening SPLs we'd really use at home or the studio, Tom's engineer and Tom himself chose direct radiators.  Most of the great records over the past 30 years used direct radiators for monitoring AND mastering.  

Controlled directivity- In a nearfield setting, highly controlled directivity can be a negative for audio quality as off axis reflections are now significantly different from on axis speaker output.  This is a big no-no for authentic reproduction.  In real life a trumpet or a guitar don't create a limited dispersion sound.  Reflections are a natural part of real life music and are needed for authentic imaging.  So authentic imaging needs its off axis output to look very similar to the on axis output, only lower in SPL (level).   Like a guitar playing in your living room, the guitar radiation pattern bounces energy off side walls that recombines with the direct sound at your ear.  This is one big reason why some rooms sound different.  .

A room with highly reflective surfaces (lets say glass sidewalls and tile floors to illustrate the point), doesn't sound good by nature.  A wide dispersion speaker does not sound good there.  These super reflective rooms can benefit by  avoiding sending energy to these highly reflective walls.  This is the time where a highly controlled dispersion loudspeaker (such as a horn) at home pays off.  It could also be controlled by acoustic control, such as drapes or absorption on the sides and rugs on the floor.  .            

Brad