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Title: Safety--or lack thereof--of dual pole-mounting
Post by: Daniel Postilnik on January 07, 2011, 07:24:14 PM

Assuming they can be made to fit, is there a way to calculate the safety of mounting two speakers on the same pole (using the onstage stands dual-mount adapter, 20" wide)? The idea is to have a little bit of virtual horizontal array with the tops (Community S-3294 - 17.4" wide) when I don't have the option to just stack them on top of some tall dual 18-inch subs.

Factors to be considered:
Speaker weight (53 lbs)
Width of base (if using speaker stand alone)
Width & Weight of base (if using single 18" subwoofer as base with satellite pole)

Thanks in advance for all the input.

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Dick Rees on January 07, 2011, 08:32:38 PM

Links to any gear to be considered would be helpful.  Saves time....

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Daniel Postilnik on January 08, 2011, 08:35:52 PM

Rather than calculating for every potential piece of gear i might use, im looking to see if there's a formula or set of guidelines i can use. As in, if theres no wind or people bumping around, whats a workable ratio of base width to top width or base weight to top weight. Thanks.

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Art Welter on January 09, 2011, 01:54:44 PM

Daniel Postilnik wrote on Sat, 08 January 2011 18:35

Rather than calculating for every potential piece of gear i might use, im looking to see if there's a formula or set of guidelines i can use. As in, if theres no wind or people bumping around, whats a workable ratio of base width to top width or base weight to top weight. Thanks.

The subject has been covered here:

http://srforums.prosoundweb.com/index.php/m/460063/0/

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Mike Pyle on January 10, 2011, 12:37:13 PM

I can't give you any weight/dimension ratios. I expect that the strength and rigidity of the stand materials and construction would be a large factor. I haven't seen anything built by On-Stage that I would be willing to put 100 lbs of weight on. I also would not care to put that much weight on any subwoofer poles or pole cups, although I know others do.

I use the K&M 24105 fork with a couple of 50 lb. cabinets sometimes. When I do it goes on top of a Global ST132 crankstand. The base diameter and weight of these stands is great enough that it is stable for my use. If they were being used outdoors or in an area accessible by the public, they would be sandbagged.

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Daniel Postilnik on January 11, 2011, 04:18:43 PM

Mike, thanks for recommending the KM24105; I'll have to use that since the onstage adapter only has a 60lbs capacity, while the KM takes 110 lbs. Surprisingly enough, the basic stand that onstage makes is rated for 160lbs.

Art, thanks for pointing to that discussion. I eventually figured out the various factors to keep in mind in regards to center of gravity, etc.

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Dave Barker on January 13, 2011, 02:40:29 PM

There is also the applied electronics package.

The L-11 or L-13's along with the speaker support.

http://www.appliednn.com/l_CU-11.php

http://www.appliednn.com/l_A.php

Title: Re: Safety--or lack thereof--of dual pole-mounting
Post by: Silas Pradetto on February 16, 2011, 10:22:49 PM

Daniel Postilnik wrote on Tue, 11 January 2011 16:18

Mike, thanks for recommending the KM24105; I'll have to use that since the onstage adapter only has a 60lbs capacity, while the KM takes 110 lbs. Surprisingly enough, the basic stand that onstage makes is rated for 160lbs. Art, thanks for pointing to that discussion. I eventually figured out the various factors to keep in mind in regards to center of gravity, etc.

As a test for pole-mounted speakers, I like to get them swinging back and forth to see how much deflection would actually cause a tipover. Having multiple speakers on one stand really isn't changing the center of gravity any, provided they're identical; it's simply adding load.

So if the stand is rated for it, and the speakers can be added one at a time without breaking the stand, and the final product is quite stable, then you might consider it safe. Maybe.