pouët.net

Hi there. Probably doesn't belong here, but just in case: any of you audiophiles, have JBL Control (25 or 28, don't know if others) speakers?

They come with a "Invisiball" wall mount which looks like this:


I have a couple of old Control 28 speakers for which I lost (in a moving) the wall mounts. Had them over some furniture so I didn't look after that a lot, but I'm moving again and want to wall-mount them. I've looked and the original mounts are something like $100 + shipping, which I find quite outrageous for a couple of ball and brackets.

So I'm wondering if any of you have these and could measure the ball's circumference or radius... and I can get it them done at a miller for a fraction of the cost.

I'm probably shooting wildly but just in case :-)

If you have the speakers, shouldnt you be able to measure the holes at the backside of them, where these mounts would fit?

Something like this?
http://www.fullcompass.com/common/products/original/256350.jpg

I could measure the hole (so I know the ball is at least smaller than that), but it's not just a hole where the ball goes in, it has some bearings inside to allow the speaker to rotate around the ball, and the ball doesn't go all the way into the hole either (it's not just some hollow opacity where the ball goes in and stand on it). It goes something like this:


If I don't get the exact measures, I'll just figure it out, get one made almost as big as the hole, and cut it down till it works. Knowing the exact size would be just better, but I can definitely work it out without :-)

This image could be used to estimate the size..



I'm fairly sure it's some even number of millimeters (or inches =)

Assuming that drawing is to scale, and my math isn't completely wrong, we end up with about 23 units of measurement, probably millimeters.

That sounds like right! I get a 21,3 measurement on that picture (got 196 pixels for the 130 vertical units, and 32 pixels for the ball, which would make it 21,333). Probably doesn't make much of a difference... and yes, more likely millimiters... the external side of the hole is about 40mm, the inner side (it's tapered) around 36/37. Don't have a caliper to measure right now, but around that.

Will make some test with a 22-23mm ball (which should be really easy to find pre-made, some steel bearing ball or something) and if it works and rotates allright, I'll just solder a threaded rod to it :-)

Thanks!

When I measured from the picture, I got a bit over 23 when measuring vertically and a bit under 23 measuring horizontally. Lost my notes though, so I can't verify. Anyway. Good luck!

So, is this thread about the diameter of Jcl's balls now? :)

it's about my lack of balls, actually :-)

Just use one of these instead