Do you have a horn for an 18 inch driver?

Frequently asked questions and the answers to them.

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Bill Fitzmaurice
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Do you have a horn for an 18 inch driver?

#1 Post by Bill Fitzmaurice » Wed Oct 04, 2006 5:37 pm

No, and this is why:
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Too large a cone won't stand up to the pressures of a horn throat. Even fifteens are vulnerable to cone damage, such as this one. Fifteens are OK in horns provided you don't try to get too much output from too few boxes (see Avoid Blown Drivers, http://billfitzmaurice.com/phpBB2/viewtopic.php?t=698), but if you want to push the maximum power possible into only one or two T48 or T60 load them with two twelves rather than one fifteen.

As for eighteens, forget about it. Aside from the fact that they are very vulnerable to damage with high power inputs, they just don't work well in horns. Horn loaded cabinets get low extension via a long path length; an eighteen takes up so much room inside the cabinet that there's not enough room left over for a long horn. Eighteens are only used by those who don't understand how horns work, or those selling their horns to those who don't understand how horns work. Or both. Here is a perfect example. This SPL chart compares a Titan 48 loaded with 3015LF driver to a Cerwin-Vega L36 folded horn, loaded with an 18.

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The eighteen takes up so much room that the CV horn is half the length required to be of any real benefit.

If you think you need an eighteen to go low, look at these response charts for 44Hz, 34Hz, and 24Hz horns, and guess which is loaded with a twelve, which a fifteen, and which an eighteen:

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Whatever you guessed, you were wrong. :?
All three are loaded with the same driver, and it's a ten. The response of a horn is defined by the horn, not by the size of the driver you put into it.


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