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In the Forum: Horn-Loaded Speakers
In the Thread: The European Triode Festival’s horns
Post Subject: Bass binsPosted by nl on: 6/15/2008
Hello Romy,

I understand the difference between the kind of "basshorn" pictured here and the proper compression-horn that you use. It is true that many DIY-types like to make basshorns in their garage without much thought to technical considerations like proper horn mouth size, rear chamber size, etc.

However, these sorts of basshorns with twin 15" drivers and a very large mouth (larger than the cones of the drivers) have a long history. The Altec 210 cabinet, as used in the Altec A2 systems with two 515-type woofers, is a prime example. The engineers of these designs did actually know what they were doing, and made a series of engineering compromises. I can imagine what they are -- shorter horn length, smaller size, lower manufacturing costs and easier installation in theaters etc. Remember, these engineers were the very same ones that also made the compression drivers we use today like Altec 288, which typically have a 2:1 diaphragm/exit ratio. Some have an even smaller mouth, like the WE 555 which uses a 2" diaphragm and a 5/8" exit.

While these are not "proper" horns in the fashion of midrange horns, nevertheless they have many horn properties such as increased sensitivity. So, they are not just funny-looking bass-reflex boxes either.

I think an interesting question would be: what are the various compromises made, and what are the results of those compromises? In some cases, the "compromise" might not be that important, for example reduced high-frequency extension might actually be an advantage overall.

Thus, maybe we could come to a conclusion that "this is a good Altec 210-type design for those who must make those compromises, while this (other) design is best for those who can accept a ten-foot-long horn in their room."

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