Heavy Speakers on Stands

[Doug Siddons]

I have just come across the NJS speaker stand rated at 60kg maximum load they have a sample test report here http://www.electrovision.co.uk/technical/2367.pdf I use HKCTA208's which are 29 kilo each so in theory could put two of these on one stand for jobs but my gut is saying it wouldn't be safe, Would be interested in opinions.

 

Normally they are mounted on top of the CTA118's with the proper frames and plates but in some applications this could be a useful solution

[Brian]

Would be interested in opinions.

As test reports go, it's meaningless.

[pisquee]

The test doesn't show how stable to stand is when it is fully loaded, and someone accidentally walks/dances/jumps into it, or trips over its leg. Or what it is like in wind.

Using an adapter bracket thing to mount two speakers on it, would then also change its stability compared to having one speaker of same weight mounted directly above the pole.

The test cert also concerns me as it states that it's only a sample, not the real thing.

[ImagineerTom]

That's quite possibly one of the most misleading and thus potentially dangerous test reports I've ever read..... In perfect compression its quite possible for that sort of weight to be held by half a dozen eggs, but a slight sideways motion and they'd all fail. Perfect compression testing like this is recklessly misleading as nowhere in the real world would an object be exclusively under perfect compression.

 

Regardless of the weight limits you have to think about the kind of weight you're creating. 60kg a couple of metres up in the air, held up entirely by a structure that weighs less than 1/4 of that amount (ie you're making a very top-heavy structure with a surprisingly small footprint) made out of the cheapest grade steel components available. Does that sound very safe to you?

 

Obviously you need to perform your own risk assessment but personally I wouldn't be happier with more than about 25kg on that stand and even then only if it was positioned somewhere where it really couldn't be knocked by a punter / band member / waiter. I might go to 35-40kg if the actual weight could be safetied to something solid nearby so that if it did topple it would be messy and embarrassing but not actually involve dropping things on people's heads.

[Brian]

I wonder on what basis they've attached a CE mark to make its sale in the EU legal?

 

They've obviously failed to have it tested to the correct European standard otherwise they've have simply used that report, or even just the declaration that it conforms.

[kerry davies]

Two questions only, Doug.

1) Can I handle 60 kg at head height? Answer; not really

2) What if 60 kg fell on me from a great height? Answer; your head not mine, thanks.

 

I used to be very careful with the twin yokes on the Lucas's and those satellites are lightweight in comparison. Even they were susceptible to instability with the bass bin spreading the weight evenly.

[Brian]

Doug,

 

to keep your insurers happy just ask the supplier for a copy of their Declaration of Conformity and make sure it states that the goods comply with the "Machinery Directive 2006/42/EC" and that it's been tested to the appropriate standards.

[Doug Siddons]

As I said originally my gut said it wasn't a safe option and was looking for someone to prove me wrong! I think everyone has the same thoughts as I did.