"Then there are flutter echo like bathroom sounds that horns also sometime produce, especially if they have a glossy surface."

What I meant was that the glossy surface causes a effect that is like or resembles the hard fluttery sound in a bathroom,  maybe it is due to the higher order modes being facilitated, anyway elliminating the hard glossy sufaces inside the horn can make a big difference in the level of unpleasentness of the horns sound as described long time ago by Romy at this site.

rowuk wrote:

There are too many great sounding shiny horns for this to be "generally" true.

Rowuk,

To talk about shine vs. harry horns surface is very difficult as, in my view, people who talk about it do not have data that was methodologically properly collected and intelligently interpreted.  Even if people did make own experiments (and very few out there who actually did it) and did hear the sonic differences than it is very difficult to interpreter the difference in proper format.

Let pretend you build a let say 300Hz MF horn and drive some kind of good 600Hz driver through it. The horn is raw polish wood and you get some kind of sound. Let pretend that you went over it before and truly know what to listen while you are listening… than you read at let say Romy’s site that the horns have to be harry  and have not gloss but some kind of texture and you want to confirm it. Here is where fan begun.

First you want your horn to be shiny. You made it shiny…but you suddenly realized that within the 2-4 days as your shine is hardening the sound of the horn is changing. You conclude that the sound in this case affected not by the surface granularity but by the density of the horn’s top layer that contact with air. You will not be wrong. You will take polyurethane for instance and seal the horn. The sound will be changed again. Then you get textured pain and mad your horn. Sound will be change again. Then a layer of mat poly. The sound will be changed again. Pay attention – it will be change and in context of the current listening you might or not might find it beneficial. Can you I bring to the game the sonic changed from electricity fluctuation? Did you equate those changes? How about the mitigation of the sonic differences from horn surface by changes in amplification, cabling, filtration etc… Who has intelligence, time and zeal to understand all dependencies/connection and to give some more or less definitive answer?

Well, the right answers will be manufacturers, right.  Well, it is not so simple. I did spoke with a few very serious horn makers who in my view do have brain and eras. They told me that cosmetics of the horns, the high sine and expensive/exotic wood is the way for them to make money. I advocated to them the notion that best sounding horn is an ugly looking horn but as you understand it will not serve their interests. I perfectly understand and respect where they stand.

I personally chose the textured finish as I feel it is a good balanced between benefits that we get from rough surface and more of less attractive look. The textured finish is pain in ass to clean. I use a compressor to blow dust from horns… The main sonic reason why I stay with textured finish is that I feel that textured finish hold slightly higher dynamic and expressive range at very low volumes. As music play very soft then textured horn (in my view) has wider ability to express emotional and dynamic nuances of original music. Do I insist that it an authoritative statement? Not at all.  I had interest in the subject; I went and spend my time to look into this. I found a conclusion that looks like satisfying my curiosity and objectives and I have settled on it. BTW, I did not invent this method. It was advised to me by John Hasqun, I just spent some efforts to test his findings and I found that he was very correct.

One more thing. I think you are committing a mistake by comparing audio horns with musical instruments. Musical instruments are resonances producing crap, literally crap from audio perspective. The whole beauty of the Musical instruments/horns is that the resonating crap is managed by human awareness. It is up to a human consciousness to structure that “resonating crap” in order to convey via expressed sound some kind of performing intentions. In case of audio horns human awareness is NOT involved in real time and the resonances and colorations that audio horns produced are fixed once and for good. This advises that ANY resonances and colorations are not good unless they highlight something that you want to be highlighted  - that has to do with your objectives as system designer… whole another subject. Anyhow, I juts would like to stress that audio horn and musical bass are very different animals, even if they have the same shape.

be wrote:

Shark skin decreases the formation of vortexes in fluid flows over surfaces and thereby reduces drag.Shark skin resembles fine sand paper and has actually been used as such.

I have actually tried to roughen the surface of a glossy horn, witch did increase the horn size, and the effect was similar to painting it with a grainy paint, therefore I am sceptical your proposal that the heard effect was due to the dimmensional alteration.
If the dimmensional change where the cause, it is very unlikely that an increase and a decrease has the same effect.

It is true that that there can not be turbulence in a horn as seen by steady flows, yet the formation of turbulence is affected by surface roughness, hence surface roughness does affect the motion of fluids over the surface, therefore it can not be dissmissed that surface roughness can have an effect also in horns.