I've amused myself, and perhaps a few others, over the last three years or so with a couple of 15s and 60 deg. horns on ~7' high tripod stands. This is fine but boys (even old ones) dream, and I'm thinking about assembling a system at the next level. To me, this means a point-source with ~10 dB more SPL or, put another way, the same SPL at 3 times the free-field distance, with, perhaps, a bit wider horizontal coverage. (I'm not looking at line arrays for a number of reasons, and, for my use, a bit of an SPL gradient is a good thing.)
But here's the thing: the speakers need to get up in the air and do so with the assistance of no more than two people who don't like to lift heavy objects.
Several methods come to mind: One standard is crank-up truss stands, as from Applied Electronics or Global Truss, with a piece of truss across the front of the stage from which everything is flown. This approach (recently discussed on the other forum) has the advantage that you can fly any shape speaker and support lights or other objects, within structural limits. The disadvantage is that you need to carry and assemble the truss and that the whole assembly is of a fixed shape and maximum width that may not adapt well to some situations.
Another is crank-up "line array" or frontal-load lifts, as from the afore-mentioned vendors or VMB. I like the flexibility of spacing and orientation but the lifts themselves are comparatively large and heavy, in addition to being rather expensive.
A third possibility I'm toying with is finding a way to use simple, not frontal-load, crank-stands (Applied L-16M, for example) to lift a balanced pair of speakers from close to ground level, as directly off a dolly board. For now let's assume that fabricating a T-bar or similar fixture is not a problem (and save the rigging safety lecture for another thread). For example, a horizontally arrayed pair of Danley SH-46s could fly balanced, and down-tilted as needed, atop a crank stand with about 3" of separation to clear the top stand section.
Several issues immediately come to mind:
Is the structurally imposed horizontal separation (say, 1/4 wave @ 1 kHz) going to make an acoustic mess? I've played some with Danley's modeling software (which looks a lot like GPA) and have not come to any firm conclusion. And, of course, the effect is highly dependent on the specific speaker under consideration.
You are limited to pairs of horizontally arrayed speakers, and you always have to use both for structural balance, even if one is turned off for narrower coverage.
If you start cranking with the speakers sitting near the ground you burn up ~3' of the available height because of the lift's minimum height. This might be OK since the maximum height of these lifts (~17') is likely too tippy and more than is needed.
The speakers need to be lifted together and held apart to clear the feet of the lift and the winch until they are abeam the top lift section. I can imagine some solution involving roller track but have not come up with anything elegant. Maybe holding them apart by hand is not that hard.
OK, enough. This whole thing seems like a common but not completely solved problem, maybe, in part, since until recently systems of this scale typically were ground stacked. I would be delighted to hear suggestions and others' approaches. Thanks.
--Frank
But here's the thing: the speakers need to get up in the air and do so with the assistance of no more than two people who don't like to lift heavy objects.
Several methods come to mind: One standard is crank-up truss stands, as from Applied Electronics or Global Truss, with a piece of truss across the front of the stage from which everything is flown. This approach (recently discussed on the other forum) has the advantage that you can fly any shape speaker and support lights or other objects, within structural limits. The disadvantage is that you need to carry and assemble the truss and that the whole assembly is of a fixed shape and maximum width that may not adapt well to some situations.
Another is crank-up "line array" or frontal-load lifts, as from the afore-mentioned vendors or VMB. I like the flexibility of spacing and orientation but the lifts themselves are comparatively large and heavy, in addition to being rather expensive.
A third possibility I'm toying with is finding a way to use simple, not frontal-load, crank-stands (Applied L-16M, for example) to lift a balanced pair of speakers from close to ground level, as directly off a dolly board. For now let's assume that fabricating a T-bar or similar fixture is not a problem (and save the rigging safety lecture for another thread). For example, a horizontally arrayed pair of Danley SH-46s could fly balanced, and down-tilted as needed, atop a crank stand with about 3" of separation to clear the top stand section.
Several issues immediately come to mind:
Is the structurally imposed horizontal separation (say, 1/4 wave @ 1 kHz) going to make an acoustic mess? I've played some with Danley's modeling software (which looks a lot like GPA) and have not come to any firm conclusion. And, of course, the effect is highly dependent on the specific speaker under consideration.
You are limited to pairs of horizontally arrayed speakers, and you always have to use both for structural balance, even if one is turned off for narrower coverage.
If you start cranking with the speakers sitting near the ground you burn up ~3' of the available height because of the lift's minimum height. This might be OK since the maximum height of these lifts (~17') is likely too tippy and more than is needed.
The speakers need to be lifted together and held apart to clear the feet of the lift and the winch until they are abeam the top lift section. I can imagine some solution involving roller track but have not come up with anything elegant. Maybe holding them apart by hand is not that hard.
OK, enough. This whole thing seems like a common but not completely solved problem, maybe, in part, since until recently systems of this scale typically were ground stacked. I would be delighted to hear suggestions and others' approaches. Thanks.
--Frank
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