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In the Forum: Horn-Loaded Speakers
In the Thread: Problems with horns: upper bass
Post Subject: A typical upperbass horn mistake.Posted by Romy the Cat on: 5/20/2006

 Romy the Cat wrote:
The biggest problem that usually people face when they listen the middbas horn is that people tend to make the middbas horns too short. In the short horn the driver shot right through the horn and the LF go not “get loaded” with the horn mouth. For instance the JBL 4560 is a typical size middbas horn, the size that most of audio people use.

JBL4560.jpg


The 4560 would give you with a correct driver ~120Hz but it will be only 200Hz of horn loading and the rest below will run as a direct radiator. If you put in this type of enclose a driver with lover resonant frequency you get even lower response from it but it has no relation to horn loading. Most of the popular Altec horns are even shallower then the 4560. For instance audio people stick into the Altec 5-9 the 515B with Fs hear 20Hz and they happy to get “bass” out of this speakers. In reality the horn loading in there do not go lower then 200-250Hz and the rest is juts sound of mass-centric direct radiator driver boosted with a port.

I have mentioned above, bringing the JBL 4560 example, that people very frequently make the upperbass horn with too large mouth. As the result they get the horn-like looking direct radiator. Furthermore the people heard about the back chamber affect and try to damp the essentially direct-radiator-like driver with back chamber. As the result then get horrible Sound with congested and unnaturally choked upper bass. One of the best illustrations is the latest modification of Bruce Edgar’s Titans with his straight horn.

On the picture you can see that the horn features inappropriately large driver with inappropriately large throat. If you place a driver into a sealed box and while the driver is producing LF you hold the cone with your hand then you get an idea how the upperbass horns with large throat sound. Another example are horns below. The idea of the intaltion was corect but the size of the upperbass throat makes those horns ridicules.

Do not repeat somebody else’s mistakes.

Rgs,
Romy

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