Originally Posted by superkyle
Ok guys I got about an hour playing with the boss platform and man this thing is fun. I’m still working on getting it dialed in. It seems the center of the couch definitely gets more TR than the outer sides. Now this could be bc there are two drivers (I’ll just remove one) or bc it’s flexing too much. What do you guys think? I would like to keep all 4 drivers but I’m not sure how to ensure it all is shaking equally. Any advice?
superkyle....Thanks for the update and details on what you're feeling. Just looked at your picture of the 4 drivers. Yes, it makes total sense that you're getting more TR in the center and less on the side seats.
There's 2 reasons for this....the obvious one is there's 2 drivers in the middle so twice as much shaker potential as the sides but that's a small reason. The other reason, and the biggest contributor is the bending beam effect that's present when using a couch as a platform. What I mean by this is think of a 2"x8" laid on its side and supported by cinder blocks on both ends. Now, imagine some one standing in the middle of that 2"x8" and someone pushing that person up and down slowly. Not only is the person in the middle going to move up and down easily due to their weight, but that person will also move up and down more than a person that is on either side that is standing closer to the cinder blocks.
To help spread that TR around more equally, I'd recommend supporting the couch in the middle with 4 extra legs that are the same length as the other 4 legs. Then underneath those 2 extra legs, place the same isolators as the other 4 legs have. This will support your couch in the middle and help spread that shaker potential more evenly across the platform. Basically, with this recommendation, you'll be supporting your couch just as you would be supporting a BOSS mini-riser as prescribed in Post 29 (1 isolator every 2 feet or so).
I'd place the 4 extra legs and 4 extra isolators on the plywood cross members in the middle, 2 on each cross-member, 1 towards the front and 1 towards the back of each cross-member.
This will keep the entire couch moving up and down more uniformly and minimize the bending that's occurring now. That bending not only increases TR in the middle but also makes that TR in the middle more limited in bandwidth and feel different than the TR on the side seats.
Hope this makes sense.