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depends if you will run some sort of limiter or not.


in infinite baffle, there is no air spring, so it is very easy to push the woofers to bottom out/damage.
 

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Discussion Starter · #3 ·
Sure, I understand.

I doubt I'll be pushing as hard as some guys around here do. I'd have the cops at my house quick.

There's a balancing point as to how much overhead you need to get a good EQ curve and how much power the woofers can take.

I don't know about a HPF, it's an option for sure though.

I'll probably be running MiniDSP with these so I can implement a HFP if needed.
 

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with no limiters in a full i.b. and not much rolloff in the signal chain, 500 watts would be on the highish side, but in the right ballpark (per driver).
 

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Discussion Starter · #9 ·
Well there you go!

Dang, why didn't I think to model them in WinISP!

Well less wattage means less money, so it sounds good to me...
 

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the plot shows extrapolation off small signal, not actual large signal, which will be a little less. as the cone move toward its limits, the bl field is less, so the sensitivity goes down.


the plot doesn't show any rolloff in signal chain. first order high pass around 5-8hz wouldn't be the worst 'guess' for many systems.


winisd is pretty good. just keep in mind that it is a model with limitations.


the inuke amps aren't going to output the marketing power. the 3000dsp will output around 2000 watts into 4 ohms or about 1000 watts into each channel at 2 ohms. that is probably the one that you want for a 4 driver 4 ohm per driver i.b.
 

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Depends on the alignment too, there's many quasi IBs around. In addition to normal subs in my room, I've got a quad set of these in full IB with an attic backspace ... and they don't need much power (that's the beauty and inherent superiority).


I've powered these so many different ways experimenting, currently I'm config'd at 225w per driver with good results. I want bullet-proof no high-pass operation though.


They're rated at [email protected], but I've found 500w apiece is too much with HT material (full bandwidth LFE)


I'd suggest anywhere around 300w-400w for no worry operation, 400w-500w being careful.

Maybe explore an INuke with prudent setting of the limiter. I always thought a pair of EP2000s and four channels of 4ohm power would be nice too.

I've got 4-15"s in addition to the quad 18 IB, so operation on the ragged edge is no longer a concern.



The version I own is pre-redesign, the newest have a back-plate that's bumped a bit more than mine.




 

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Discussion Starter · #14 ·
And 4 of them is enough for your room?

I think it was you that suggested 8 for my room. I've been on that notion ever since.

Yours may be quite a bit smaller than mine though.
 

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No, it wasn't enough.


If you notice they're supported by (4)15"s.



That said, everyone is different. But, four dual opposed manifolds, spaced appropriately, would be quite good...both wrt output, and acoustically.


MKTheater has eight of these in his baffle wall build, and he couldn't be much happier.
 

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Discussion Starter · #17 ·
Well I'm still wanting 4 manifolds with 2x18" in each one, with a total of 8.

It sounds so insane that I don't even want to tell anybody. :)

The big question is whether I or not I put them at the top of the vaulted ceiling near the peak, or spread out more towards the sides.
 

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With regards to IB subwoofer builds, what are the optimal manifold dimensions for the IB3-18's? Do they need any EQ once built and setup?


This is something that I have never previously considered, but, my curiosity is getting the best of me!
 

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Discussion Starter · #19 ·
I'm in the same boat Marty!

From what I understand, it doesn't matter what the size of the manifold are. You just have to have it tall enough and deep enough to mount the drivers, but the width doesn't matter so much.

EQ appears to be about the same as any other sub.

The real issue is the very real possibility of bottoming out the drivers by pushing them over the limit.


Note, all this is just from stuff I've read and I don't have any real world experience with IB.

My house being a one story and having a lot of attic area around my living room is the only reason why I'm considering it.

Tapped horns were originally where I was going but my wife would totally not go for that. At least not in "her" room. :)
 
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