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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Steven Barnes on November 05, 2012, 09:18:09 PM
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I do not hang out much in the Lab Lounge, but I thought this topic would be more appropriate and useful over here.
We have been using QSC KLA stuff for the last year or so with great success, but we keep running into situations that we cannot fly the PA and it must be set up on a stage as there is no room off SL or SR on the ground. Coming from the world of L-Acoustics, D&B, Etc. I was used to being able to angle bumpers and such as needed, but not with these boxes. If you stack the boxes on top of subs they were useless as the second box would be firing over the audience unless you were trying to cover a balcony.
Anyways I came up with this idea a little while back and finally had some time this week to start playing around with stuff and get a working prototype going. They are adjustable from 5*-45* and are rated for 3 boxes with a 9:1 Safety Rating. We are going to be testing them out over the next couple weeks.
Before anyone says it, these are only going to be used for ground stacking tops on subs, and will not be used when the rig is flown.
I am also working on a couple more of these for use with JBL VRX Series.
(http://i229.photobucket.com/albums/ee264/sbarnesvta/photo-6.jpg)
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Very interesting, looks like good work.
How much effect does that have on stability of the speakers? Looks like at higher angles it'll push the CG forward a bit.
Does your custom frame have a hard connection to the subs to help stabilise it?
Cheers,
David.
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Very interesting, looks like good work.
How much effect does that have on stability of the speakers? Looks like at higher angles it'll push the CG forward a bit.
Does your custom frame have a hard connection to the subs to help stabilise it?
Cheers,
David.
The speakers are very stable sitting up to a 30* angle (as it sits in the picture), going up to 45* it is definitely front heavy and needs to be strapped to the subs.
I have a pin setup designed for the bumper to lock it to a KLA181, but we use these tops with a couple different types of subs (KLA181, HPR181i, KW181, JBLSRX728, and L-Acoustics SB28). For the others, we run 2 heavy duty straps from the bottom sub through the bottom of the angle bump to the other side of the bottom sub.
I will get some more pictures of the setup today on top of some subs.
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If the adjustment bars at the back were vertically straight instead of curved, and the top half of the base rigged to slide instead of being hinged to the bottom half, then when you changed the angle the array would slide back and maintain greater stability over the lower base section.
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Looking good... I would extend the front feet a couple inches further outwards. Or add Mikes idea into the design.
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Keeping an eye on this thread - I've been eyeballing a set of 6 VRX or KLA boxes to add to inventory. I'd need a solution for mounting on top of pairs of horizontally stacked QW218s.
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If the adjustment bars at the back were vertically straight instead of curved, and the top half of the base rigged to slide instead of being hinged to the bottom half, then when you changed the angle the array would slide back and maintain greater stability over the lower base section.
Thanks for the input, I had looked at something like this, but chose to go the hinge route for simplicity reasons. I know this puts my CG a little further forward, but I do not for see it being an issue. It is also nice that they folder up pretty tight for easy storage in the KLA Roadcases.
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Here are a couple more pictures of the prototype in action. We are still making a couple small design changes, but this will be pretty close to the finished product.
(http://i229.photobucket.com/albums/ee264/sbarnesvta/photo-7.jpg)
(http://i229.photobucket.com/albums/ee264/sbarnesvta/photocopy-3.jpg)
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Here are a couple more pictures of the prototype in action. We are still making a couple small design changes, but this will be pretty close to the finished product.
Pretty neat setup, but I'd rather see that strap wrap around under the subs rather than hook into the handle.
Mac
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Pretty neat setup, but I'd rather see that strap wrap around under the subs rather than hook into the handle.
Mac
Mac,
The handles seem to be an integral part of the enclosure, compared to a screwed-on/bolted-on additional piece of hardware. Other than potential tampering with the hooks (which are under tension anyway), what is your concern?
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Mac,
The handles seem to be an integral part of the enclosure, compared to a screwed-on/bolted-on additional piece of hardware. Other than potential tampering with the hooks (which are under tension anyway), what is your concern?
Would you fly the speakers from those handles? If not, I wouldn't use them as support.
Mac
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Would you fly the speakers from those handles? If not, I wouldn't use them as support.
Mac
And by that logic I wouldn't use those straps to fly the speakers…Spansets and shackles could be an option, I guess - that seems a little clunky to me, though.
I haven't used those loudspeakers myself, but a read-through of the user guide shows that they use a sort of coffin lock for interlocking the cabinets. Maybe Steve can integrate those into his his design and use them instead of ratchet straps? Or he could possibly use the integrated threads…
Thoughts?
EDIT: It seems like Steve already thought of that… (http://forums.prosoundweb.com/index.php/topic,140748.msg1304911.html#msg1304911)
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Pretty neat setup, but I'd rather see that strap wrap around under the subs rather than hook into the handle.
Mac
That was me just being lazy at the shop this morning, as you can see in the pics there is plenty of left over strap length on the ground, I purchased these straps long enough to be able to completely wrap a block of 4 subs either 4 high or 2x2. There will also be 2 straps (one front and one back) per stack.
Also: To play devils advocate, the handles are actually milled into these boxes as part of the enclosure and not an additional piece of hardware bolted to the side of the enclosure.
These will definitely be completely strapped as a solid loop in the field when they are used.
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I really like this idea. Anyway you can get a pic of 3 boxes on top?
I'd like to see how the angles work out, see if it is possible to work the boxes so the top is horizontal to floor.
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I really like this idea. Anyway you can get a pic of 3 boxes on top?
I'd like to see how the angles work out, see if it is possible to work the boxes so the top is horizontal to floor.
I will not be at the shop again until monday, but I will see if I can get some pictures with 3 boxes setup.
The KLA boxes are roughly an 18* box, so 3 boxes would be 54*. The angle bump only goes to 45* the way I have it designed. If the math is correct the top box should be sitting about 9* above horizontal, but would still be plenty usable if you needed the extra horse power. You would have to shade the bottom box or get the rig pretty high up in the air to not kill people up front.
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I have had quite a few requests for some pictures of a single KLA and 3 KLA's stacked.
Any other request when I have the time to set this up again?
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Here are a couple more pictures with 3 and 4 boxes stacked. The bottom of the bracket is definitely going to need to be extended another 6" or so to help center the weight as Matt suggested earlier in this thread.
Another issue is going to be the stability of the PA stack, by the time you get 3 tops on 3 subs, you are getting pretty tall with a rather small footprint.
I believe I have enough metal to build one more prototype with the longer base, now I just need to find a bit of time to get another built.
3 Boxes, Angle of the top of the top box is 10*
(http://i229.photobucket.com/albums/ee264/sbarnesvta/photocopy-4.jpg)
4 Boxes, The only situation I could see this being useful would be a very small outdoor stadium section covering bleachers. We used to do something like this for graduations, but with bigger boxes.
(http://i229.photobucket.com/albums/ee264/sbarnesvta/photocopy2-2.jpg)
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Here are a couple more pictures with 3 and 4 boxes stacked...
I just stumbled across this thread. Nice design! We own some KLA boxes too, and I could definitely see myself using that setup, at least for 2-tops-per-side events. It's been a while since you posted this; have you used them in the field? Have you made any modifications to the design?
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need to be extended another 6" or so to help center the weight as Matt suggested earlier in this thread.
By the look of it, more like 10-12".
Great idea!
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Hi Steven
were you able to develop something like this for Jbl Vrx
Would like to buy
Please help
Read the rules, fix your display name.
Thank you for your cooperation.
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Another thing to consider would be one additional strap from the top to the sub on the back as a safety. We've seen the party people and the stupid ones that would release the strap on the side.
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Another thing to consider would be one additional strap from the top to the sub on the back as a safety. We've seen the party people and the stupid ones that would release the strap on the side.
What makes you think some drunk idiot wouldn't find the ratchet in back, the one that is 18" away? The solution to this is barricade and security personnel. Any other solution that doesn't require special tools will get figured out by a determined fool.
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I'm keen in these brackets any chance of getting the design emailed to me so I can make a pair? Thanks! :-)
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I'm keen in these brackets
Please go to your profile and change the "Name" field to your real first and last name as required by the posting rules displayed in the header at the top of the section, and in the Site Rules and Suggestions (http://forums.prosoundweb.com/index.php/board,36.0.html) in the Forum Announcements section, and on the registration page when you registered.
Mac
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never mind.
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They had a show here at work. Local provider. They had 2 VRX on top of a 728 on end for sidefills. They just had some blocks of foam cut with an angle under the back of the VRX to tilt the stack forward.
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Did they have them strapped or connected, or were they just sitting on the foam?
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We need a pair of these asap! Please provide a link to vendor. Thank you!
This is an old thread, these were also custom made. In your haste to sign up you may have overlooked the rules that we require real names to participate. Please update your profile.