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Discussion Starter #1
I've been playing with building out a home entertainment center with shelfing to replace my stand alone equipment stand and stand alone sealed subwoofer enclosure. While doing this, I have the opportunity to modify my enclosure design some and was looking at doing a PR build.

To do this build, I definitely cannot do the standard cube design that is shown in other threads. My question is, can this rectangular box design work where two are on one side and one is on the other?

Note, I do have a couple inches spacing of it from the wall, and the cabinet is not resting on the subwoofer enclosure. Also, I would add some diagonal bracing between the sub/pr's. Volume is 8.9cu ft, not counting the subs or bracing.



 

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That would be equivalent to placing the port of a vented enclosure in the adjacent room. The issue there is if the port/PRs output is well within a 1/4 wavelength (or 1/2... can't recall) of the contributing frequencies... Such a build would be tuned low enough that it might conceivably work. I don't really see the point, though? I'm not sure if it would be worth taking the risk of some unforeseen poor performance...
 

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Discussion Starter #3
That would be equivalent to placing the port of a vented enclosure in the adjacent room. The issue there is if the port/PRs output is well within a 1/4 wavelength (or 1/2... can't recall) of the contributing frequencies... Such a build would be tuned low enough that it might conceivably work. I don't really see the point, though? I'm not sure if it would be worth taking the risk of some unforeseen poor performance...
Well, the point was to get lower extension than my 4.5 cu ft cube. I also have a vented design in similar amount of space that I was messing around with around the same time, but can't remember how the modeling went. Maybe I'll mess around with that some more.

The only other option would be a similar sized sealed build. Really wanting to get something that doesn't extend towards the sitting location quite as much, but could be a bit taller and definitely longer.
 

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Discussion Starter #5
It would need to be a foot away. Can you design it wider to get all 3 on the front?


Yeah, it is possible I could make it work with reduced equipment space, but then there is the chance my wife would kill me for having what looks like 3 18" subs.
 

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Discussion Starter #6
Well, looks like I could build upwards and build cabinets up above it to make it look integrated.



 

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Discussion Starter #8
Looks good. What tuning frequency are you shooting for and does your amp have the appropriate hi-pass filter?
Maybe this is a bad assumption, but from my research when I build the current enclosure, could I get by with utilizing a BFD? I have a EP2500 for the amp and no high pass filter, but was planning to purchase a BFD.

I need to play with the volume some and run some simulations to determine tuning. I haven't built a ported enclosure before, so unsure what drives people to select a specific tuning. If I could keep it reasonably flat to 20HZ with a slight dip through 15HZ I'd be more than happy.
 

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It would need to be a foot away. Can you design it wider to get all 3 on the front?


I have about the same kind of a plan with Mal-X Gen2 wit 2 passives. I have understood that for 18" Mal-X element it is enough to put it 5 inches off the wall. I have now downfiring sealed box for the element with that clearance from the floor. Isn't it enough that the amount of moved air by the element/passive have free way from the sides (area of the "cylinder" sides is more than the area of the element)?

If that is not the case I think I have an issue with my plan (active element facing front, PR's on the sides, one passive will be 5 inches from the wall)...

EDIT:
Maybe I'll do main driver downfiring with 5 inch clearance from the floor and both PR's firing front. Would this be feasible?

EDIT2:
I don't want to borrow this thread for my own questions/plans so I started a new thread.
 

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Discussion Starter #12
Ideally yes, but if it's not an option.......
Yeah, I'm hoping it won't be an issue. I'll have the active sub in the center, with the passives on either side. Would it be better to secure the box to the wall, or leave some space? I was thinking attaching it to the wall would be more stable and would avoid issues with them all being on the front.
 

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Discussion Starter #14 (Edited)
Well, it looks like I have the PR's lined up, so this will be a go.

I'm still unsure on whether I should couple it to the wall to avoid oscillations, but potentially having more wall vibrations, or leaving some space and potentially having oscillations due to the height. I could take the height even to the top of the cabinets as well to get a bit more volume. The real purpose of this rebuild is the modern, European style walnut cabinets. The outer baffle of the sub will use the same walnut plywood for a built in look. It might be harder to achieve that while maintaining some spacing.

Edit: Found another with this orientation, although 15" instead of 18". It also looks deeper than it is wide: http://www.hometheatershack.com/forums/ported-subwoofer-build-projects/44910-single-15-two-15-page-rankings-7.html#axzz2FYdvQXAa

An alternative would be to still go tall and short in depth, but doing a ported/vented build instead. Keep the sub low, and have the port coming out the top.
 
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