Suspended mass stability query

[TheInternet]

First off apologies this is not science per se (engineering at best) but the audience here is probably best placed to answer.

I'm suspending some speakers by cable from a ceiling and wish to arrange the cabling to minimise movement and have the following options. Anybody enlighten me to which is the better choice? (I'm pretty sure it's B...btw)

Side view:

[anonymous-user]

TheInternet said:

First off apologies this is not science per se (engineering at best) but the audience here is probably best placed to answer.

I'm suspending some speakers by cable from a ceiling and wish to arrange the cabling to minimise movement and have the following options. Anybody enlighten me to which is the better choice? (I'm pretty sure it's B...btw)

Side view:

better is option C, that crosses the cables, but attaches them to the speaker ABOVE it's CofG (ie, at the top!!)

[TheInternet]

Max_Torque said:

better is option C, that crosses the cables, but attaches them to the speaker ABOVE it's CofG (ie, at the top!!)

Top fixed would make sense but the cabinets are unblemished and not designed for it so it's A or B only. Sounds like of those you'd go for B.

[Einion Yrth]

TheInternet said:

Max_Torque said:

better is option C, that crosses the cables, but attaches them to the speaker ABOVE it's CofG (ie, at the top!!)

Top fixed would make sense but the cabinets are unblemished and not designed for it so it's A or B only. Sounds like of those you'd go for B.

I can't see anything to stop A swivelling until its CoG is below the mount point, thus becoming C; similarly I can see B becoming D in fairly short order.

[TheInternet]

Einion Yrth said:

I can't see anything to stop A swivelling until its CoG is below the mount point, thus becoming C; similarly I can see B becoming D in fairly short order.

It certainly needs consideration. The diagrams don't show the dimensions well, my gut says it would need a pretty good shove to achieve it. It's straightforward to add some tethers to prevent rotation. Could alternatively add eyelets to route the cables through.

[RizzoTheRat]

Mark on the centre of mass and then think about how it moves in relation to the mounting points, maybe even mock it up with some cardboard and string. I think if it's roated clockwise the bottom right mount will move to the left quicker in B than in A, meaning it's less stable as it'll end up inline with the centre of mass sooner.

Can't you hang them upside down?

[TheInternet]

Upside down is not feasible without a lot of work; at present it is effectively a shelf with a cable mounted at each corner. Will probably add some small eyelets to prevent rotation like so:

[XM5ER]

anonymous said:

[redacted]

Have one of these

That's not aimed at you OP, it just tickled me is all.

[Huff]

TheInternet said:

Upside down is not feasible without a lot of work; at present it is effectively a shelf with a cable mounted at each corner. Will probably add some small eyelets to prevent rotation like so:

That short link needs to return to the ceiling mount that side, to do any good; and then you'll find that the 'rear' cable stay needs to be fixed at ceiling level a fair way further back, to keep it stable.

MaxTorque is right of course - can you find a way to use the suspension as 'option c' recommended above the speaker's top surface - say, a sheet of ply taking the fittings - then just hang the speaker (vertically) directly from that ?



NB pro PA cabs usually come with detailed manufacturer recommendations available for 'flying' them, if that's what we are talking about.

[TheInternet]

Huff said:

That short link needs to return to the ceiling mount that side, to do any good; and then you'll find that the 'rear' cable stay needs to be fixed at ceiling level a fair way further back, to keep it stable.

With the added cable stay I was hoping it would be akin to this:

[Simpo Two]

The pros would probably mount them upside down on a rigid pole, eg Unicol, like a video projector.

[coanda]

I would suggest A being more stable than B, especially when there is the chance of movement - B will have the longer cables for the same height so will be less ideal from a stability point of view. B will also, naturally want to unwind so you'll be more likely to end up with upside down speakers if they are knocked anyway. Shame you can't suspend them from a single cable.