mustang guy Posted May 15, 2011 Share Posted May 15, 2011 I have been trying to understand the theory around horn speaker effectiveness, and I found an illustration that was made in 1926 that may have given me an epiphany. Look at this: Horn length is proportional to the wave length. Wave length at a certain frequency is simply the speed of sound divided by the frequency. For example, the wave length of 50 Hz is calculated by the speed of sound (1,126 fps) divided by 50, which equals 22.5'. Look at the 1926 drawing above. The wavelength is 6' there. Take the speed of sound (1,126 fps) and divide by 6, and you have 187 Hz. At 1/2 way, the fundamental wave and the harmonic waves all touch like at the beginning and at the end. In this drawing, a tone of 187 Hz coming out of a horn, would suffer no loss at 0', 3', and at 6'. The 1 1/2' horn shows the fundamental wave not ligning up with the harmonics. That means a 1/4 horn is not as good as a 1/2 length horn for a specific frequency. Here's the thing I wonder. If I want to tune a horn for 18 Hz, should the length be exactly 31' 3"? Please correct anything I said that was wrong!!! And... please please please keep it simple!! Thank you very much. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted May 16, 2011 Share Posted May 16, 2011 you will like this http://www.rocketsciencecanada.com/rocketsciencecanada/Sound/Horns/Tool_ExponentialCalculator.asp Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 16, 2011 Author Share Posted May 16, 2011 you will like this http://www.rocketsciencecanada.com/rocketsciencecanada/Sound/Horns/Tool_ExponentialCalculator.asp Indeed I do like it! Would be uber-kewl if that data could be plotted and scaled to make a visual of the resulting horn. Nothing that can't be done on graph paper or in AutoCad, but it would be much faster. Thanks SF Quote Link to comment Share on other sites More sharing options...
boom3 Posted May 16, 2011 Share Posted May 16, 2011 not all the columns are labelled...what are they please? Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 16, 2011 Author Share Posted May 16, 2011 They are labeled, they are just not lined up. Proportional font. [:S] Quote Link to comment Share on other sites More sharing options...
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