I have 4 Berkline 090 theater seats with installed Buttkickers in a row. I have noticed that the Buttkickers have an impact on the floor and although I’ve used the coasters that Berkline provided I think the seats should have vibration isolation from the floor for two reasons. First an most important is that you won’t make a soundboard out of the floor and second is to give less mass for the Buttkickers to hammer against so as to retain the energy in the chair.

I’ve seen what others have done and I’ve not really seen a very good system so I came up with one and I’m looking for ideas on what’s right or wrong and I’ll gladly share my notes and photos at the end for anyone who wants to build something similar.

In building an isolation system you have to consider what you’re trying to isolate and what types of stress will be created. Most of our stress is in the downward weight of the chairs with people on them. Isolators are not really built for a varying weight but the weight on the system will most likely change. I looked at products and decided that I would split the chairs into one frame with two chairs. I will use 4 Neoprene floor mount isolators per frame and each frame will hold two chairs. The Neoprene isolatrs are rate each for weight from 85-175 pounds. After some math with adding the 4 isolators and subtracting the weight of the chairs and steel frame it works out that both chairs together will work best within the weight of 200-560 pounds. Remember this is just the frame, which sits on the floor.

Next is attaching the seats to the frame. I will use cylindrical neoprene isolators and use 4 per chair that will be a total of 8 connections to the frame. Again I was concerned in the weight in picking these out but I had to recognize that I need to consider sideways shear also and so I went with 125 pounds per isolator with 20 pounds of shear strength. Add the 4 together and you have about 430 pounds max load per chair.

The frame and the isolators will add less then 4 inches in height to the chairs.

Ideas and questions please.

John

Hi John,
Great Idea man, where did you get these from?
regards

Thanks.

The isolators are sold by Grainger.com. They have local stores all over. I've changed a bit on the design now that I'm into it but I should have it done by this weekend. I've spent enough time on the Berkline chairs tat I should be able to tell if it made a difference and I'll let you know.

john

Well I finished the isolation system and I took a couple pictures of the frame.

It works as expected and it does a couple things. The frame is built for two chairs and I built two frames for my four chairs. It s nice to have the chairs locked down in place. Secondly and most importantly is that it lets me turn down the buttkickers because the energy from them is no longer shared with the floor but is kept in the chairs. Even though I had hard sturdy floors I sitll produced vibration in the floor prior to the isolation system and now I don't.

I think these chairs that use the Buttkicker should have built in isolation and I've never heard anyone even mention it which I find surprising because it really made quite a difference. I also have two Buttkicker amps, one for each two chairs but I've moved to only one and no longer see a need for the second amp.

John

Man thats an excellent idea. Much credit to coming up with that. Im going to have to use that idea on my theater.