New member here. I have six 135 lb JBL 4732A cabs. We’re all getting a bit tired of lifting these things, and technology has moved on. That said, the components therein should still be useful to repurpose into single 12” line array cabs. Hoping to build 12 of these for a max of 6/side to use with four 4719A subs. Can anyone point me to a good proven line array cab design I can build out of 13 ply baltic birch that will work with the 2206 12” LF driver and the 1.4” 2447 HF driver? I was interested in Mike Sprague’s LA112 design, but he said it only works with the Eminence Deltalite 2512.
Tech manuals for the JBL SR4732A specify either 2226H or 2206H 12" drivers, the Eminence Deltalite 2512 TS parameters are kind of "in between" the two.
The LA112 design would work with any of the three drivers, though the the low frequency alignment would be different.
The larger excursion capability of the JBL drivers could use an additional pair of ports with extended depth, but the basic design and rigging of the LA112 design seem OK for this generic type of line array.
The JBL 2447H 4" voice coil 1.5" exit driver can handle an octave lower crossover point than the 2" voice coil 25mm/1" exit Eminence driver, crossed at 1600Hz in the LA112.
A lower crossover point will have less horizontal comb filtering in the crossover region, an improvement.
JBL specifies the throat of the 2447H as 38mm/1.5".
Most line array "waveguide" throat adapters are 36mm/1.4”, you may want to file a transition in the throat to avoid the "bump" restriction dropping from a 1.5" exit.
I'd suggest looking at the polar patterns and cutoff frequency of various throats to determine what is most appropriate for your use. The B&C ME148 has good loading down to 500 Hz, it would offer a flexible crossover range to optimize the LF/HF transition.
Art
The LA112 design would work with any of the three drivers, though the the low frequency alignment would be different.
The larger excursion capability of the JBL drivers could use an additional pair of ports with extended depth, but the basic design and rigging of the LA112 design seem OK for this generic type of line array.
The JBL 2447H 4" voice coil 1.5" exit driver can handle an octave lower crossover point than the 2" voice coil 25mm/1" exit Eminence driver, crossed at 1600Hz in the LA112.
A lower crossover point will have less horizontal comb filtering in the crossover region, an improvement.
JBL specifies the throat of the 2447H as 38mm/1.5".
Most line array "waveguide" throat adapters are 36mm/1.4”, you may want to file a transition in the throat to avoid the "bump" restriction dropping from a 1.5" exit.
I'd suggest looking at the polar patterns and cutoff frequency of various throats to determine what is most appropriate for your use. The B&C ME148 has good loading down to 500 Hz, it would offer a flexible crossover range to optimize the LF/HF transition.
Art
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