In Reply to: PA horn scoop bins posted by Andy G on July 01, 2001 at 04:56:38:
Dear Andy,That looks like one of my scoop designs. I designed a lot of scoops a long time ago, but am not a believer nowadays. The interaction from the front of the driver and the horn mouth worries me especially with short ones. If you must have scoops then make them as big as you can and with at least an 18" driver, 21" and 24" drivers are better still. This way all the output below the crossover point (and it should be a low one of around 80 Hz) will come from the horn, and not the front of the driver, minimising any phase shifts. So, get the girly Gamma 12's and put them in a front loaded horn for low mid use and get some real bass drivers.
If you really must have scoop bins, and I will only go along with you on this one if your entire record collection is dub and dance hall reggae, because that's all they sound good with, then drivers with the same parameters for other horns should be used, (high EBP's) i.e. a high Fs and a low Qes.
The Eminence Gamma 12 has a very low EBP of 76, oh dear.
Did I mention that Precision Devices has a 12" driver with an EBP of 282, oh well I just did. Should interest all you horn nutters out there.
Scoops away!!! And in with the 6th order bandpass for PA low end.
Best wishes,
Rog Mogale Ebn Hons
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