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In the Forum: Horn-Loaded Speakers
In the Thread: An ultimate horn profile?
Post Subject: An ultimate horn profile?Posted by Romy the Cat on: 4/15/2005
Looking at the variety of exponential, parabolic, conical, tractrix, hyperbolic and whatever ales horn profiles out there I was thinking that we probably incorrectly approach the entire subject of horn profile analyses.
We listen the horns and we feel it is indicative enough. We apply to the horns an abstract logic and pretend that our horns are noses of submarine, winds of airplane or the jet propulsion exits. Yes, the theories are bult around all those commercial applications but those commercial application target completely different goal then we do in audio. In those commercial application the behavior of the exposed curves is the only thing that is important. If those application pay attention to air pressure that passes along the curve then they care about it only in a reference to the body of the curve, and the do not recognize the pressure wave as a self contained precious entry. Also all those commercial application and all engendering thinking that associated with it deal with essential parallel source of air. This is never a case with our audio horns.
Consequently, the mentioned (and few other reasons) made me to review our thinking about “an ultimate horn profile” and about our ability to interpret the auditable result and project those interpretations to the horns.
It is undoubtedly that the major characteristic of sound reproduction is a shape (profile) of the front of pressure wave. The engineers do not like to talk about it because they can’t objectively measure or visualize it. However, let pretend that the front’s profile is the key. If so, then it would be easy to understand that there is nothing more devastating for the front of a pressure wave then steps within sequential horn opening. Any, deviation from constant explanation rate would format the front of pressure wave and presumably screw the sound (let presume that inside of compression chamber there is no reformation of the wave’s front, that is not exactly true)
Ok, that was kind of all well-understood things but what we do after we understood it? We take a “wining profiles horn” and attach it to a random driver and then we build our theories how those profiles behave. We “kind of” forget that the compression drivers already have the built-in beginnings of the exponential channel. Each driver has own build-in opening rate and own length of the wave-channel. The only thing that we actual use is the diameter of the throat but we even not care that before the exit the driver might have 5”-6” of horn sitting right inside. Did I mention that we not really know or care what rate this inner-horn?
The point that I am trying to make is following: when we take for instance the Altec 802 and palace it into 1” tractrix and then “compare” it with 2” JBL 2440 then…. beside the differents in the drivers do we also deal with the COMPLIANCE of the specific “inner-horn” with the profile of our “outer-horn”?
Dose it means that the “ultimate horn profile” would be a profile that would be a DIRECT AND FLAWLESS CONTINUATION of the GIVEN SPECIFIC DRIVER?
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