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In the Forum: Horn-Loaded Speakers
In the Thread: An ultimate horn profile?
Post Subject: Center your drivers, boys.Posted by Romy the Cat on: 4/15/2005
 cv wrote: |
| This is but one reason why I'm asking Martin Seddon to make me a pair of 160Hz horns... |
|
Another problem….
Chris, be carefully with those large 160Hz horn and S2. The guys who make then have no instruments to center the mounting holes very precisely (wood-turning machines apparently do not furnish this level of precision, not to mention the concrete pouring machines :-) As the result, if you have a compression driver with own channel, and the driver is not exactly centered within your external horn (a fraction of millimeter does mater) then you would have a slight suck-off at middle. For instance my horn has a centering mechanism (courtesy to John Hasquin) that allows centering the driver. I use a high resolution RTA (0.25db at 1/12 octave) running a sweep and moving the driver. Wherever I get a perfectly flat response at 4kH there I would consider the drive in the centered. Moving the driver within 2-3mm introduce an octave wide drop between 3kH and 5kH with minus 2-3 db at 4kH. Some of the drivers are less sensitive and particularly the drivers where the throats at the end of the phase plug but if you driver has own inner-horn than the centering it within the outer-horn become very important.
Rgs,
The caT
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