Question concerning db sensitivity

Someone recently told me that in their experience, in general, that the higher the db sensitivity of a given speaker, the more you sacrifice in terms of sound. In other words, lower db rated speakers [ 86-88 ] typically sound better. Any thoughts on this?

Yes this is true. This matches my experience with conventional box speakers. As generalizations go, this is actually quite a good rule of thumb (there are exceptions).

The light weight and rigid diaphragm structures necessary to produce very high efficiencies (ceramic, metal etc.) generally result in an under damped system (high Q - resonances). Furthermore, the highest efficiencies are often achieved by using a long voice coil in short magnetic gap which means the linear operating range of the driver excursion is modest and it is less efficient at dissipating heat than a short coil mounted in a more expensive massive magnet assembly; this results in more distortion and compression at modest SPL's and the speaker will sound positively dull and boomy at high SPL's.

I haven't mentioned horns here, all I will say is that I have seen plenty of horns used for sound reinforcement but rarely, if ever, have I seen a horn used as a professional studio monitor; this fact alone speaks volumes about the fidelity of high efficiency horns...

There is no truth to this. Speaker sensitivity has no more to do with sound quality than amplifier power, which is zilch.

John,

Your statement is as one sided as it is inaccurate. How can you possibly say that speaker sensitivity and amplifier power have NOTHING at all to do with sound quality?

Perhaps you do not regard distortion, resonance, dynamic range and accuracy at typical music SPL's as being in anyway related to sound quality...in which case I could understand your extreme position much better.

John,

Ok I understand this has simply been your experience. I misread your statement as a fact or well known "truth".

Sorry...

Adman227,

For some reason I would have thought this issue was less subjective than others

Everything in audio is highly subjective, which is why I took the time to qualify my reply with a description of a couple of the general measurable issues/compromises in the choice of high or low speaker effciency. Of course, there are many more issues which can lead to many exceptions but then this would no longer be a "generalization" if we were to plunge into great details.

If this information helps guide you to choose a speaker - Great!
A "generalization" like this, however, is absolutely no substute for auditioning and narrowing your choice to speakers that you personally like the sound of, which I suspect was really John and Tvad's point.

BTW I think whomever said that pro monitors do not have horns in them should look at what is on the pro/studio market.

Mechans,

I meant real professional monitors for mixing/mastering in a studio....NOT sound reinforcement or for nightclubs or concert or myriad of speakers with the monikor "monitor" or "pro".

I think you will find that horns were popular in the 50's but eventually fell out of favor (in professional studios) in the 70's as non-horn designs began to achieve sufficient loudness levels for use as main monitors (mostly used to impress clients by playing back what they just played in a very realistic fashion).

Horns are almost completely out of the professional studio market as far as I can tell. They are almost never used as nearfields and only rarely used as main monitors.

Anyway, don't take my word for it, after all, many of my most accurate statements have been totally discredited/contradicted/distorted by one or another of the "experts" on these forums so what's new...

Perhaps this, from a person who is passionate about the Altec Lansing 604 horn designs (famous in the 40's), may convince you;

Studio Monitor Evolution

Jim,

Here is an example.

Take a classic famous well respected "hall of fame" type speaker like the Wilson Watt Puppy 7.

Look at the two distortion plots at 90 db SPL and at 95 db SPL (top curve is output SPL and bottom curve is THD+N SPL)

Notice that as the sound level is raised by 5 db SPL the distortion components increase by much more (8 or 9 db SPL)....this is always the case, even on great speakers such as this. The higher the output levels (towards realistic live sound) the relatively greater distortion ...until eventually the distortion becomes audible (and perceptively very loud). This point will vary for each system of amplifier and speaker but generally even small systems can be made to be perceived as sounding very loud (but in a small system it is mostly the harshness of distortion and not ACTUAL SPL level that gives the impression of loudness)

Johnk,

Horns are used in studios.....usualy on the wall a set of compresion horns with BR bass will be in use.

I agree the horns are almost exclusively used for main monitors which are mainly used to impress clients at high SPL's.

I was trying to say that most nearfields for mixing and mastering do not use horns and that even for main monitors(the big soffit mounted beasts) there has been a significant shift away from horns ( a process that only begain in the 70's). Older studios may still have horns in place. Horns have not been entirely displaced from the studio.

Duke,

Good point. Waveguide loaded mid ranges and tweeters are widely used everywhere even in nearfields. I draw a large distinction between these designs and traditional "compression" horns ....but like most things in this hobby many designs share some physical similarities.

Here is a good independent article on this subject (Ralph at AERONet). Waveguide Mid range Design

There are more details and a discussion of waveguide versus compression horns on this website (for those seriously interested...I realize details can tend to make most people's eyes glaze over in a hobby which is largely intended to be just a fun pastime).

One of these days I'd like to see how a two-way with waveguide-loaded tweeter compares side-by-side with something like an ATC SCM-50.

Yes that would be interesting.

ATC adapt a vifa tweeter with a short conical waveguide on the small two way SCM 20. The soft mid dome is grafted onto the woofer in this two way design. The woofer shape also appears to act as a mid waveguide as well as a woofer. The crossover is lower (2.8 Khz instead of 3.5 Khz, as on the SCM 50) probably because of cone breakup issues or driver beaming in the two way design. The dome may also act as a phase plug and help keep beaming issues above the crossover (this last bit is just my speculation).