Rerurn to Romy the Cat's Site

My first thought is for a "very dense layer of foam", or maybe very good felt, between two hard, even "slipping surfaces", such as 2X4s or even "5/4" (1" net) or 3/4" net oak boards.  This might be a fairly thin sandwich that the entire length of the mouth of the horn could simply rest on, right above the beam, with felt or something also used as a slip anywhere the horn might otherwise touch on the house framing, so the horn could just sit there and vibrate, more or less by itself.  A few "cleats" fastened to the house, but not the horns (or vice-versa) could prevent the horns from "walking around".  Apart from foam, I have used strips of sheet Transite (compressed asbestos fiber) for "slipping blocks" betweeen concrete floor sections on bridges and parking structures, etc.  Much lower frequency, of course, but it certainly "works".  This scenerio could perhaps be re-created at the middle of the horn, resting the "slipping block" on something spanning the joists over another bearing point.  Steel "U-channel" is compact and strong and widely available for this purpose of distributing weight across ceiling (attic floor) joists.

The sling idea is a good one (if you could figure out where to hang the slings!).  Rather than rubber, consider industrial "web" slings, which can be rated for use on truly gigantic loads that are moved with cranes, etc.  Slings like this are widely available, once you start looking.  Again, this also creates "point loads".

No doubt someone else will mention the "motor mounts", which are indeed compact and plenty strong, but which may have a disadvantage in your case, especially at this point in time: they create very severe "point loads" that would be hard to counter with wood framing alone.  Perhaps you could mount them on metal plates or "U-channel" to distribute the load across a sufficient number of framing members.

Depending on how (and how well) the "dissipation" points work to bleed energy, one might still face the need to "drain to ground" any unwanted energy not "converted to heat".

Best regards,
Paul S

Rerurn to Romy the Cat's Site