Stacking Otops?

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Preston
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Stacking Otops?

#1 Post by Preston »

I’m currently running 4 per side stacked on a 4ft high scaffolding and I strap everything together. I’d like to get some more height and am considering adding an 12 -18” platform/box on the scaffolding to raise the speakers up.
I’ve also thought about adding a few more otops to the stack…
Has anyone tried stacking more than 4 high? I’m a little concerned about the stability, wind, etc, etc.

Bruce Weldy
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Re: Stacking Otops?

#2 Post by Bruce Weldy »

Preston wrote: Fri Jun 10, 2022 11:32 am I’m currently running 4 per side stacked on a 4ft high scaffolding and I strap everything together. I’d like to get some more height and am considering adding an 12 -18” platform/box on the scaffolding to raise the speakers up.
I’ve also thought about adding a few more otops to the stack…
Has anyone tried stacking more than 4 high? I’m a little concerned about the stability, wind, etc, etc.
If you are using the locking chevron corners and a strap - I'd think you'd be pretty safe as long as they are strapped tight to the platform and the platform is sufficiently wide to keep the whole thing from tipping over in the wind.....

Of course, you could always split the stack in half and crossfire them if it looked like wind was going to be an issue.

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Bruce Weldy
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Re: Stacking Otops?

#3 Post by Bruce Weldy »

Although, I'm wondering if you get past 4 a side with no curvature like a line array, are you going to really cut down on your vertical dispersion?

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Bill Fitzmaurice
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Re: Stacking Otops?

#4 Post by Bill Fitzmaurice »

The curvature of a JArray is only necessary when the lowermost cabs are well above the close in audience, so they have to be tilted down to cover that zone.

Bruce Weldy
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Re: Stacking Otops?

#5 Post by Bruce Weldy »

Bill Fitzmaurice wrote: Fri Jun 10, 2022 3:32 pm The curvature of a JArray is only necessary when the lowermost cabs are well above the close in audience, so they have to be tilted down to cover that zone.
My concern was a stack of 6 OTops with the bottom one 6 feet off the ground (if he uses a spacer to get 'em up higher) might be over the heads of the crowd with the vertical dispersion getting smaller with that tall of a stack.

Am I off-base here?

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


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Bill Fitzmaurice
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Re: Stacking Otops?

#6 Post by Bill Fitzmaurice »

With the bottom cab 6 feet off the ground and the person nearest to it at least 6 feet out no worries. You'd need for the lowermost cab to be at least 8 feet up with a seated audience close in to really need down tilt of the lowermost cab.

Bruce Weldy
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Re: Stacking Otops?

#7 Post by Bruce Weldy »

Bill Fitzmaurice wrote: Fri Jun 10, 2022 4:48 pm With the bottom cab 6 feet off the ground and the person nearest to it at least 6 feet out no worries. You'd need for the lowermost cab to be at least 8 feet up with a seated audience close in to really need down tilt of the lowermost cab.
Thanks.

So what happens to the vertical dispersion as you add cabs straight up? I know the more you add, the more the dispersion decreases, but how much in terms of degrees?

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


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Bill Fitzmaurice
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Re: Stacking Otops?

#8 Post by Bill Fitzmaurice »

It's halved with each doubling of the array height, if it's straight. But the upside to that is that the energy isn't lost, it's projected further. Depending on the array height and frequency sensitivity drops by 3dB with each doubling of distance instead of 6dB. For that to occur the array must be at least three wavelengths high.

Preston
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Re: Stacking Otops?

#9 Post by Preston »

Thank you everyone for the input! Yes, I use locking chevron corns and strap everything to the scaffold. The platform is only 3ft x 2ft which has been perfectly acceptable for the 4 high stack. I’ll have to see if there’s room to crossfire a pair. However, that also reduces the height on the line array… but might be a great solution if I need 6/side (or 8!) I have zero interest in flying anything, so I suppose there is a practical limit to a ground stacked line array.

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Bill Fitzmaurice
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Re: Stacking Otops?

#10 Post by Bill Fitzmaurice »

Rather than crossfiring a pair for a very wide spread between the stacks use one or two as center fills.

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