Originally Posted by Johnson4
Fabulous build! I've just spent the morning reading through the entire thread as I'm just about to start my own build... yours will certainly be in my head as I do it.
A few questions sprang to mind as I was reading:
- Your IB setup -- do you get any flex in the "cabinet" walls at all? They don't seem as reinforced as some builds I've seen (although the opposing drivers would help counter the mechanical forces I suppose).
- The access port to the IB cabinet -- why doesn't that pop open? I would have thought any opening in the face of the cabinet would be detrimental?
- The bass traps -- must admit, I don't fully understand the science, but does any box filled with insulation act as a bass trap? What about a wall? Do you find the room is too "dead" with all that padding?
- The riser -- is it important to fill it completely with insulation? And why did you put two layers of flooring on the riser (separated by Green Glue)?
Again, congratulations on your build -- simply inspiring.
I have not noticed any flex in the "cabinet" walls at all. As mentioned previously I think it is the most solid structure I have ever built and by my estimation the IB chamber weighs 3000 lbs. The dual opposed drivers do help. The manifold walls are very solid - The manifolds are constructed of 2 layers - one of MDF and another of baltic birch ply. They are also attached to a base that is full of 300lbs of sand. The walls of the IB chamber are triple layered with 2 layers of 5/8 drywall and a layer of OSB with Green Glue between the layers. The access port to the IB "room" is also constructed of 2 layers of MDF with Green Glue between the layers. It has a gasket to prevent air leaks and is screwed into a framework which presses the cover against the gaskets - again it is very solid. It would have been nice to be able to not have the access panel, but I needed some way to access the drivers for installation and to finish off the inside of the room with insulation etc. Most people do not need to climb inside their subwoofer.
The room is not too dead. In fact I still plan to add more bass trapping in the rear - its probably impossible to have too much bass trapping because it takes a lot to be effective at really low frequencies. The rear bass traps might be covered to reflect high frequencies and absorb low.
I built my riser so it could be used as a giant bass trap in the future should I decide to do it. Everybody here seems to fill the riser with insulation and it should help damp some resonances. I figured it was inexpensive to do it before the carpet was in and impossible to do after. The two layers on the floor is just to prevent any rattles in the riser.