Change to Horns or stay Dynamic

Horns sure have their fans, but to my ears, they sound nasty. To each his own, YMV, etc.,etc..

Unsound, many horns do sound quite nasty. I have yet to hear a prosound hornspeaker that doesn't, especially at high volume levels.

Two potential sources of nastiness are frequency response problems and diffraction. Horns all need some sort of equalization, and usually fairly complex equalization, before their frequency response is reasonably smooth. Not all designers go to the trouble to smooth the frequency response - perhaps because many horns still sound edgy even after they measure smooth. Which brings us to the second problem: Diffraction.

Diffraction occurs where there is a fairly sharp discontinuity in the horn flare or profile. For example, many horns have a fairly sharp-edged mouth, which results in diffraction at the mouth. Others deliberately induce diffraction within the horn to widen the radiation pattern. Diffraction has little measurable effect on the steady-state frequency response curve, but it's audible because of where it occurs in the time domain: Just a little bit later than the original sound. The ear is good at masking (ignoring) a lower-level coloration that occurs at the same time as the main signal, but very poor at masking a coloration that occurs later in time. Also, the ear's sensitivity to the type of coloration diffraction imposes is level-dependent; that is, diffraction becomes more audible (and more objectionable) as the level goes up. Those prosound horns that drill your ears at high volume levels - that searing edginess is probably diffraction (and higher order modes - a diffraction-like phenomenon that occurs within any horn, but is worse in some than in others).

So to get back to Unsound's comment, not all horns are created equal, and not all horns are employed equal. In fact, historically low coloration has not been the top priority in horn design, perhaps because knowledge of how to build a truly low-coloration horn was lacking. Dr. Earl Geddes is the leading expert on low-coloration horn design; he calls his devices "waveguides" to emphasize that their function is guiding the sound waves (controlling the radiation pattern), rather than acoustic amplification. The "horn" that I use is a Geddes-inspired waveguide.

Duke

Horns sure have their fans, but to my ears, they sound nasty. To each his own, YMV, etc.,etc..

Unsound,

I agree that horns can sound harsh and have colorations and just plain sound bad, but what loudspeaker technology doesn't have it's bad examples? Factors affecting horn performance include abrupt mouth termination, discontinuities in the profile (diffraction horns are notorious for this), forcing a horn to play outside of it's design bandwidth etc.

I am sensitive to horn artifacts and the main reason I originally brought up these two speakers is because by all accounts they do not have the traditional horn sound. Lynn Olson, a well known speaker designer and a person that by his own admission is very sensitive to horn honk, was impressed by the Jazz Module when he auditioned it at one of the shows. Keep in mind that both the Summa and the Jazz module use waveguides, that are shallower than wide with straight sided walls and have smooth round-overs at the mouth termination. As i mentioned earlier waveguides and the theory behind them, have been developed by Dr. Geddes who is also the one that coined their name. Suffice to say that there are key differences between waveguides and horns. This last statement does not of course preclude the fact that horns can sound good and some actually do so, namely some examples of the pro monitors mentioned by Shadorne.

George

Fair enough. I have heard most of the highly touted, and might I add fairly expensive horns, but not the Geddes "waveguides". I will try to remember to make an effort to do so. If the Geddes "waveguide" systems are indeed so different, perhaps they shouldn't be grouped with horns at all?

Try to listen to Tactrix horns or LeCleach profiles too, new profiles, implementations and time alignment clean out the tipical horn sound, I had a lot of Vintage horns from Altec Valencias to Hartsfield toploaders and the newer versions are way more sophisticated and better sounding.