Originally Posted by ijansch
Thanks for pointing me to this thread. I think I’m going to try this in my build. A couple of questions.
1. Have you considered creating a website about this subject? With 115 pages this thread is massive and even with the pointers at the start it takes a while to take everything in. A website with instructions, case studies, frequently asked questions etc might help new builders. I’m happy to assist with that if you’d consider it.
2. I was thinking of creating a riser just high enough to be able to load the drivers with the magnets in, and then put a static riser of the same height around it so it blends in. Do you have experience with putting the carpeting from the boss to a regular riser, allowing the carpet to stretch a bit but ensuring you don’t see the gap? Also, how much does the riser typically lower when someone steps or sits on it? Or is it sturdy enough to not really give way when stepped on?
3. With a full size riser, would the riser have to be open on the bottom to keep it an ‘open baffle’? Or can I use 2 plywood sheets for top and bottom?
ijansch....Thanks for the note and questions about your BOSS design. I am considering a website with details on this technology. Stay tuned.
For your full size riser being planned, if you use 6" lumber for the framing with 3/4" plywood on top of that framing, that will be enough space to accommodate the prescribed JBL's with the magnets into the cabinet. If a 6" high riser is too high, there's also a low profile MBQuart driver linked in Post 29 that can be used instead (the MBQuart DS1-304 driver). This driver would allow the platform to be constructed of 4" lumber with 3/4" plywood on top since it's only 3.5" deep.
If you used the 1.25" hemisphere isolators linked in Post 29, the gap between your BOSS riser and the floor below will only be .5" and this won't be noticeable especially after carpet. This is how my back row riser is constructed and the gap disappears. Others are using this same construction technique and the smaller isolators for their full size risers with great results. With these smaller isolators, there's only about an 1/8" compression when people are stepping onto and off the platform...it's not noticeable. With the larger 2.5" hemisphere isolators needed for a mini-riser, those compress about a half inch when stepping onto or off the platform. But once seated, the compression is only about a 1/4" since that load gets distributed around the platform.
If you want to have a static platform surrounding your BOSS platform as you describe, I don't see any problems bridging that gap with carpet. Just be sure there's a gap all the way around the perimeter of the BOSS platform so that it's not touching the static riser at any point or this will rob TR from your butt. Also, make sure to allow the BOSS platform inside the static platform to breath easily since it's an open baffle design. Since you probably don't want the gap between the static and BOSS platform to be very big, I'd suggest making openings in the sides of the static riser to allow some breathing room for the drivers in an open baffle configuration.
Too keep your BOSS design simple and performing at it's maximum, keep the bottom of the riser open to allow some breathing space. This will ensure an open baffle and great BOSS performance for any application.
Sealed BOSS risers are becoming popular. But, they have to be engineered to deliver maximum performance since the sealed riser will limit excursion of the drivers which isn't desireable. Sealed BOSS platforms also provide SPL which can help smooth in-room bass response for every seat. The sealed cabinet needs to be engineered to provide the optimum SPL while also maximizing the BOSS shaker potential. There's a few variables that go into sealed BOSS designs but it can be done with great results once those variables are optimized to work together. If interested in a sealed BOSS design, send me a PM. Since there's some engineering time involved with sealed BOSS setups, there's a one time fee for the delivered design package. That package includes dimensional drawings customized for your room layout. A materials list that includes details on lumber type, insulation type, number of drivers, type of drivers, isolator details, needed power for the custom sealed BOSS, wiring diagrams, etc.
If you want to simply experience BOSS technology in an open baffle, just build the designs described in Post 29 and enjoy.
It's probably one of the easiest builds on AVS......the cuts don't have to be very accurate and the design is very forgiving since it's an open baffle design.
As always, please let us know of any questions that come up as your design comes into focus.
Hope this helps.