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Discussion Starter #1
I've got a bonus room over my garage that has attic space down each side of the wall. In the attic space there is only insulation on the wall of the bonus room (see attachment) and not on the floor or the ceiling of the attic space. There are also attic vents on the floor that vent to the outside. Given that there is no insulation apart from the bonus room wall does that pose a problem for an IB installation? I have a neighbor about 20 feet away from the mentioned attic space. Will an IB be a constant nusance? My joists are 24" on center and I can easily put a manifold centered down the wall.

I've always thought building sealed boxes and then putting them into the wall would be cool, but why go through the hassle of that when I could just do an IB and use the attic space.

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What are your thoughts?

Thanks,
 

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Your IB will be just as loud in the attic as it will be in your room. One thing you could try if you were really nervous about loudness would be to put your existing sub up there and listen outside the house to see how loud it is. Other than that I dont think you would have any problems with an IB.
 

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That is exactly what I would do... test it, but not just right outside that room. Go over to your neighbors house and listen. Of course, depending on what you own right now, an IB is likely going to be much more powerful and extend lower, thereby possibly harder to test in reality.

You mentioned building sealed boxes and putting them into the wall. If you end up believing that an IB will be too loud for your neighbor, an option would be an SLLT similar to what Rodny did... see IB Makeover in the Sticky Threads here in the IB forum. He ended up enclosing his IB and he talks about how much quieter it ended up being in his house.
 

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Definitely put your sub in there and see how loud it is outside. Something to consider... you could also insulate the attics ;). I would say, since you're interested in IBs (and since you mentioned the possibility of a small sealed sub... and an IB is a super large sealed sub... I get the impression you don't like ports), build one in each attic and see how it sounds at your neighbors. If too loud, get some insulation and add it to the room. It can't be that expensive. If still too loud, just build in a "smaller" enclosure as Sonnie mentioned. This could be a medium sized sealed sub (compared to an IB). If the response doesn't give the low end you want, add deeply tuned port to convert it to a SLLT. Each step allows easy modification to move to the next should it be necessary.
 

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Discussion Starter #6
I like the systematic approach recommended by jagman. I initially fell for the IB concept because of how unique and custom it is, the fact that it takes no floor space, and in all honesty a manifold seems simpler to build than some of the speakers I've built in the past (ported, slot vent, and passive radiator).

I will try moving the sub to see how it sounds. Like mentioned earlier though, my sub won't be a completely accurate comparison as it only has in room useable output to about 30 Hz. I've also never driven it much above max SPL of 95 db's or so as it seems like its going to break at those volumes :) FYI I have a Velodyne VX-10 ($160.00 online price).

If I were to seal off a large section of the attic, will having large panels create resonance that I would be able to hear through the speakers or wall? I'm not about to add bracing every 12 inches to raise the passband high enough on a box that's like 40 cubic feet :scratchhead:
 

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Discussion Starter #7
I would say, since you're interested in IBs (and since you mentioned the possibility of a small sealed sub... and an IB is a super large sealed sub... I get the impression you don't like ports).
I have never heard an expensive or upper end, properly designed ported sub, likewise with sealed. My experience has been with stuff that cost 300-500 in the audio boutique shop and in that range the sealed subs always seem to sound tighter, less bloated than the ported.

I think I could pull of a sealed design better than I could a ported therefore I am leaning towards sealed or IB. I'm aware of the trade offs, efficiency, SPL, etc. per driver but none of those seam to make me feel the need to go ported. I think I would convert from IB to a ported SLLT if I felt the IB lacked in the low range, but given my listening experience and coming from my single 10" (100 watt RMS) driver in a 2300^3 ft. room I think whatever I do next will be a huge improvement :)
 

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Another thing that could factor in is how big are we talking? There are ib's floating around ranging from two 12's to four 18's (hopefully 22's soon thanks to FI :devil:) and things differ greatly depending on what you want from this project.

As far as the ported/IB comparison, I recently went from a single 15 to two 18's in an IB and while the IB is obviously worlds better I was quite satisfied with both. Coming from a single 10 you are going to get knocked out of your chair no matter what you go with.
 

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Discussion Starter #9
I was originally thinking of starting out with 2 15" in a manifold built for 4. I guess if funds allow when I pull the trigger I would probably just go for 4 anyways. Sheesh, I need to get off this forum before I get the bug and start bugging my wife about another speaker project:R
 

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You could start with two 15's... add two more later if you feel the need. I would get a couple of good ones though with good xmax.
 

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Discussion Starter #11
I was thinking of using the AE IB15's which have 18mm xmax, that's not huge I know. Given the price of the AE speakers I could buy four of them for the price of say two Fi or Soundsplinter 15's. It would be nice to buy something with a little more reputation though, there isn't much on the web about the AE IB15.
 

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We could always model it for you against some other drivers if we have the specs. How much are they?

The Fi IB's are $199/18" and $119/15" for 4 or more.
 

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Unless the prices have changed recently you can get 4 ib15's for $400. With 3.0710 L displacement each that is very respectable. Even at that price they still cannot match a pair of FI IB18's though.

Dont forget to use the handy subwoofer comparison chart!
http://pages.sbcglobal.net/ginmtb/woofer_comparison_chart.htm
 

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Discussion Starter #14
Driver SD (cm^2) Xmax (mm) QTS FS(Hz) Vas Efficiency (dB) price Displacement p-p (liters) $/per liter Notes
Ficaraudio IB 15" 810.0 22.0 0.77 24.4 269.5 90.0 129.00 $ 3.5640 36.20 $ Shipping included, discounts for 4+
Acoustic Elegance IB15 15" 830.0 18.5 0.70 16.0 439.0 86.0 129.00 $ 3.0710 42.01 $ Discounts for multiple drivers

The AE 15 has more SD than the Fi 15. Also a much lower Fs. Does the lower Fs mean that the AE will play lower without eq boost? Xmax is better on the Fi 15 which would make the sub handle boost better in the low end which may be necessary with an Fs of 24.4 Hz.

I don't think the price difference between those two drivers is significant enough to be a deciding factor.
 
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