ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [All]   Go Down

Author Topic: sandbags on speaker stands  (Read 1791 times)

Weogo Reed

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 291
  • Western NC,
    • LiveEdge
sandbags on speaker stands
« on: April 22, 2021, 07:32:46 PM »

Hi Folks,

    Indoors, with 60# speakers at 7' height up on a solid concrete stage I've been using one 20# bag.
These are speakers out of the way of foot traffic. 
Outdoors, with the 7' stands I've used two 20# bags.

    For an upcoming outdoor event, with the same 60# speakers but up at 10',
am planning on two circular 25# bags per stand.
These will be away from foot traffic.
There might be a light breeze blowing, but real wind isn't likely.
(Stands are rated at 100Kg 220#.)

    How much sandbag weight do you put on tripod speaker stands?

Thanks and good health,  Weogo
Logged

Riley Casey

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1699
Re: sandbags on speaker stands
« Reply #1 on: April 22, 2021, 09:40:01 PM »

After finding USS stands starting to slip with a sandbag at the base of the vertical tube hanging from the flat bar arms I started using a bag wrapped around the tube at  each of the rubber feet. Three per stand but it made them very reliable and resistant to people kicking of tripping on the legs.

doug johnson2

  • Full Member
  • ***
  • Offline Offline
  • Posts: 115
Re: sandbags on speaker stands
« Reply #2 on: April 22, 2021, 09:45:03 PM »

I use two bags filled with 35 lbs of lead on the leg braces of my stands.  Never an issue with approximately 90 lbs speakers at 6 ft or light trees at 10.

Logged

Dave Garoutte

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2654
  • San Rafael, CA
Re: sandbags on speaker stands
« Reply #3 on: April 23, 2021, 12:07:02 PM »

I use two bags filled with 35 lbs of lead on the leg braces of my stands.  Never an issue with approximately 90 lbs speakers at 6 ft or light trees at 10.
Whenever possible, if I have to go high, I also try to strap the upright to something solid.
Logged
Nothing can be made idiot-proof; only idiot resistant.

Events.  Stage, PA, Lighting and Backline rentals.
Chauvet dealer.  Home of the Angler.
Inventor.  And now, Streaming Video!

boburtz

  • SR Forums
  • Sr. Member
  • *
  • Offline Offline
  • Posts: 310
  • San Francisco Bay Area
    • SoundWizard Productions
Re: sandbags on speaker stands
« Reply #4 on: April 23, 2021, 01:15:47 PM »

I use two bags filled with 35 lbs of lead on the leg braces of my stands.  Never an issue with approximately 90 lbs speakers at 6 ft or light trees at 10.
I have found that the flat bar leg braces on Ultimate brand stands (ts90b) are fixed to the legs via a press fit, and I have had them pull out, which means catastrophic stand failure. Ultimate has been very good about replacements (I have never had this happen while the stand was deployed, thankfully), but I cannot speak as to whether they would replace a broken speaker or worse. I doubt it. I no longer use the fat bar as weight support. I recall reading somewhere afterward on a piece of Ultimate literature that the bars should not be used to support weight.
Logged

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2127
    • HappyMac Digital Electronics
Re: sandbags on speaker stands
« Reply #5 on: April 23, 2021, 01:30:01 PM »

I've never used sandbags on stands.  Tripod stands on their own are fairly stable. The amount of additional weight needed to make an impactful difference to prevent tipping would be significant.

Indoors I don't see any benefit of using sandbags.  Outdoors, what I do is drive fenceposts into the ground and strap the stands to that.
Logged
Brian Jojade

Weogo Reed

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 291
  • Western NC,
    • LiveEdge
Re: sandbags on speaker stands
« Reply #6 on: April 23, 2021, 11:43:34 PM »

Riley,

    Yep, I've seen the same type stands sag with weights on the horizontal bars.

    Doug, thanks for the height and weight notes.

    Dave, there's a good chance the stands will be anchored to rebar pins driven in
 the ground behind a 4' concrete wall, that will be behind the speakers.

    Bob "I recall reading somewhere afterward on a piece of Ultimate literature that
the bars should not be used to support weight."  Thanks for this, some
lighter fill speakers will be up on US stands.

    Brian, I hope you never hit underground power or sprinkler hosess or wires!
Sandbags can damp sway if a wind gust gets speakers moving.
I have to do what the university safety offer says  -  we we are on good terms and
I want to keep things that way    : -)

    Does anybody know of printed industry standards along these lines?

Thanks and good health,  Weogo
Logged

Kevin Maxwell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1496
Re: sandbags on speaker stands
« Reply #7 on: April 24, 2021, 10:27:25 AM »

I went to a car show back in 2015 and I didnít take any pictures of the cars. There were always people in the way of getting a good picture of the cars. I just took a picture of the base of a stand that had a banner between 2 stands. If I did it right that picture is attached here. It seems to be filled with water. This looks like a really good idea to weigh the stand down. I am not thrilled with the water part of it.

Many years ago I was doing an outdoor event (Relay for Life) and we had a 3 speaker cluster on stands splayed to get the coverage we wanted. And a small gust of wind came along and blew the speakers down. We had basically made a sail. They were in a place where there werenít people so no one got hurt. I have since been very careful of speakers on stands. 
Logged

Mal Brown

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1076
Re: sandbags on speaker stands
« Reply #8 on: April 25, 2021, 11:37:59 AM »

I do (or did...) a lot of outdoors events with high wind. Kite surfing derbies and the like.   I use concrete slugs with eye bolts cast in.  Probably 50lbs per slug.  1 slug per pole.  I have a number of lengths of non stretch rope with carabiners at each end.   I take a few round around the pole at the ' collar' and hang the slug just off the ground.   I've only had 1 K10 come down.  Pole and everything got taken out when 9 sections of fencing went airborne after the promoter loaded it down with sponsor banners and 0 wind relief... knucklehead.  Thankfully nobody got hit by any of it...

K10 came down on grass and needed 1 port tube glued back on inside as it popped off a flange cast into the face.  Easy enough.  a few feet different and it would have been side walk with a much different ending I suspect...
Logged
Bass player, sound guy.
Fb Gorge Sound and Light
WillyandNelson.com

Dave Pluke

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1350
    • BIGG GRIN Productions
Re: sandbags on speaker stands
« Reply #9 on: April 27, 2021, 03:17:32 PM »


    For an upcoming outdoor event, with the same 60# speakers but up at 10',
am planning on two circular 25# bags per stand.
These will be away from foot traffic.
There might be a light breeze blowing, but real wind isn't likely.
(Stands are rated at 100Kg 220#.)


Murphy is chuckling at "real wind isn't likely"  ;) .

The math gets complicated and depends on the surface area of your speakers, but you have a moment arm the length of 10' minus the height of the tripod coupling. That can get surprisingly forceful with a small breeze on a 60# speaker.

I would second the motion for concrete slugs with cast-in eye bolts for tie downs over sand bags.

Dave
Logged
...an analog man in a digital world [tm]

Flying direct to nearly everywhere out of ATL

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2127
    • HappyMac Digital Electronics
Re: sandbags on speaker stands
« Reply #10 on: April 27, 2021, 04:40:44 PM »

Brian, I hope you never hit underground power or sprinkler hosess or wires!
Sandbags can damp sway if a wind gust gets speakers moving.
I have to do what the university safety offer says  -  we we are on good terms and
I want to keep things that way    : -)

    Does anybody know of printed industry standards along these lines?

No, I never have hit anything.  Proper precautions are taken when doing outdoor shows to make sure everything underground is marked.  It's the same as the tent company driving stakes into the ground, or temporary fences, etc.

This is documented ahead of time as to where things will be placed and are to be free for driving things into the ground.

My concern with sandbags is that if there's enough wind to sway the tripod, placing sandbags in support positions that are not marked for sandbag placement trades one risk for another.

Putting a 50 pound weight on a cross arm that is not designed to hold that weight adds a new potential failure point that didn't previously exist.
Logged
Brian Jojade

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 22231
  • Wichita, Kansas USA
Re: sandbags on speaker stands
« Reply #11 on: April 27, 2021, 09:16:08 PM »

"I will use whatever brand and model of stand you find that documents such use of sand bags in the user/owner manual, and I will use them only in full conformity with the manufacturer's instructions."  See where this is going?  /nudge, wink

If the client wants to prescribe a "solution" then the client needs to prescribe a "fully designed solution."

Edit ps:  the topic of stabilizing tripod-style loudspeaker stands comes up maybe once a year?  I recall a few years ago the discussion got into the geometry and wind loading calculations (maybe involving Langston Holland? Can't recall for sure) and was very informative.  If anyone remembers and can find that thread...

My thoughts - 60lbs at 10 ft to the bottom of the loudspeaker is a force multiplier on a big vertical mast, the resistance at the bottom a factor of base area and friction.  I didn't take statics.. but there's a bending force (moment?) caused by the wind load.  I'd wager that most aluminum, folding tripod loudspeaker/lighting stands are not designed for this dynamic, lateral loading.  Adding weight to the leg braces seems like a way to cause the legs to pull in and reduce the base area; the concrete block/eye bolt with a tether that puts the load on the apex of the tripod (where the legs meet), or a T-bar fence post driven into the soil, with the post secured to the stand's upright mast seem preferable.  The former would not cause the base area to change but does nothing for the dynamic load on the mast; the latter solves that issue up to the top of the fence post.

How windy is "we don't have much wind here"?  In Kansas we call a day with 20 MPH winds "calm." ;)
« Last Edit: April 27, 2021, 09:36:14 PM by Tim McCulloch »
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Weogo Reed

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 291
  • Western NC,
    • LiveEdge
Re: sandbags on speaker stands
« Reply #12 on: April 28, 2021, 10:19:55 AM »

Hi Kevin,

    That's the first I've seen a bag like that.
I like the four feet on the stands.

    Mal, gotta love those sponsor banners.

    Dave you are correct about the chuckling.
Am adding steel anchors and ropes.

    Brian, I already cleared driving steel in the ground  - 
no sprinklers, power or control wires there.
The stands are steel, and fairly stout:
 http://www.worklifters.com/products/lw-130

    Tim, It would be great to see stand manufacturers specify
what can and can't be done with their stands as far as anchor
weights, points, etc.
 
Thanks, good health and be safe,  Weogo
Logged

Jim McKeveny

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1208
Re: sandbags on speaker stands
« Reply #13 on: April 28, 2021, 10:59:16 AM »

These will be away from foot traffic.

Unpaved?
Logged

Mal Brown

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1076
Re: sandbags on speaker stands
« Reply #14 on: April 28, 2021, 11:45:16 AM »

Driving stakes is prohibited in the waterfront parks and event spaces where I normally work.  Too many irrigation breaks.  The folks who payed out the system for the city are long gone and left no map behind...  We are the self proclaimed wind surfing capital of the world...  Hood River, OR Winds here are no joke April to mid or late September.

Out walking the dog, I've already seen one guy attempt a full loop while foil boarding this year.  Usually it's at least June before the knuckleheads try that ;-)  Been crazy warm so the water people are early this year.  Fire season is going to suck...
Logged
Bass player, sound guy.
Fb Gorge Sound and Light
WillyandNelson.com

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2127
    • HappyMac Digital Electronics
Re: sandbags on speaker stands
« Reply #15 on: April 28, 2021, 04:19:20 PM »

Driving stakes is prohibited in the waterfront parks and event spaces where I normally work.  Too many irrigation breaks.  The folks who payed out the system for the city are long gone and left no map behind...  We are the self proclaimed wind surfing capital of the world...  Hood River, OR Winds here are no joke April to mid or late September.

Out walking the dog, I've already seen one guy attempt a full loop while foil boarding this year.  Usually it's at least June before the knuckleheads try that ;-)  Been crazy warm so the water people are early this year.  Fire season is going to suck...

In cases like that, a tripod speaker stand may not be the appropriate tool for the job then.

If the equipment isn't engineered for a specific task, and you decide to do your own napkin engineering and get it wrong, you're asking for trouble.
Logged
Brian Jojade

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1947
Re: sandbags on speaker stands
« Reply #16 on: April 29, 2021, 05:25:08 PM »


Edit ps:  the topic of stabilizing tripod-style loudspeaker stands comes up maybe once a year?  I recall a few years ago the discussion got into the geometry and wind loading calculations (maybe involving Langston Holland? Can't recall for sure) and was very informative.  If anyone remembers and can find that thread...

How windy is "we don't have much wind here"?  In Kansas we call a day with 20 MPH winds "calm." ;)

More than a few years ago, but statics are the same now as in 2009:

https://forums.prosoundweb.com/index.php/topic,118012.20.html

Speakers have changed..

Art
« Last Edit: April 29, 2021, 05:27:57 PM by Art Welter »
Logged

Weogo Reed

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 291
  • Western NC,
    • LiveEdge
Re: sandbags on speaker stands
« Reply #17 on: May 11, 2021, 05:33:41 PM »




Hi Folks,

    Follow-up notes:
We had 25mph winds Friday for setup, and rain showers twice.
Saturday commencement had winds up to 15mph.
Am glad I didn't count on the usual calm air around here!

    The 60# speakers were anchored with two 35# sandbags and
tied to pins in firm soil.(It took significant effort to get the pins out.)
The site electrician showed me where power was run so
no chance of hitting electrics with the pins.
The speakers didn't need to be raised all the way up, they were at about 9' height.
Smaller, lighter fill speakers got two 15# or 25# bags.
Everything stayed absolutely in place.

    Thanks for all the comments and advice!

Good health,  Weogo
Logged

ProSoundWeb Community

Re: sandbags on speaker stands
¬ę Reply #17 on: May 11, 2021, 05:33:41 PM ¬Ľ


Pages: 1 2 [All]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.042 seconds with 20 queries.