Peter,
Would love to see a couple more pics of this solution!
Tom
Here are a couple of pictures of the prototype testing. Several improvements have been made since. The top pin in the (bottom) picture is shown not all the way through, just had to increase the clearances a little to make it work correctly or in this case swap the poles / subs around.
Its important that you have a substantial base to make it stable. The double 21" are 710mm x 750mm and the pole is arrange so that the load hangs exactly in the centre.
I'm not happy with the quality of the winch and I am currently looking for a replacement. I had to modify the one shown in the picture to get the worm drive to engage correctly and weld the assemble in position to ensure its ongoing safety.
You can also remove the handle and use a battery drill / socket to drive it up and down.
The line-array is a single 8" + horn. It is possible to get 6 boxes on it but the bottom box is around head height.