I mounted a buttkicker LFE Transducer (from a Buttkicker LFE kit) beneath a 4’ x 5.5’ riser. The riser is constructed of ¾” plywood glued and screwed to a base constructed from 2”x8” lumber. Because of seat mounting requirements, there are 8 2x8s in 4 feet so the riser is very stiff. The transducer is bolted directly thru the ¾” plywood (and thru a piece of 2x8 to stiffen the floor) about 1.5 feet from the rear of the riser, beneath the 2 old style folding theater seats. I used 4 of the rubber isolaters from the kit as feet for the riser. I estimate that the risers and seats weigh around 170 pounds. Pictures:
I have a similar transducer mounted to a loveseat of about the same weight as the riser with 6 K28 isolators. At first, I wired the 2 transducers in parallel to the bk amplifier. When I played a bass heavy movie scene (beginning of Serenity), I noticed that the transducer on the riser overloaded almost immediately and continuously (started rattling – hammering noise), while the one in the couch only rattled once (as it normally does during that scene).
My first thought was to replace the LFE kit isolators with 4 of the heavier K28s that I have. This made it quite a lot better, but it still goes from no shake to overload very quickly. In order to stop the rattling, the amp must be turned down so that I can feel very little shake for most of the movie – kind of defeats the purpose. Removing the feet completely (carpet) reduces shake but not overload.
Anyone have any recommendations that might help? Is it possible that the unit is defective? My next project will be to switch the transducers between the couch and riser to see if they behave similarly, but this requires two people and some effort. Would more power help? I am powering it with a crown 1500 amp. It is rated at 1050 watts at 8 ohms (bridged) – has to be higher for 4. I can switch to a buttkicker 1000, but the amps are difficult to reach at the moment. Would going with the much more expensive large isolaters ($15 each) help? I suppose that it would be possible to cut out parts of the 2x8s to lessen the stiffness of the riser, but that would be a last resort and rather permanent...
Thanks in advance!