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Discussion Starter · #1 ·
I'm looking into build a Sealed Sub for my family room that opens up to nearly 3/4 of my 2900 sq. foot house. I mainly watch movies and listen to music when i can, so basically a 70/30 ratio of movies/music. My budget is $550 including materials and shipping costs. I have already priced out everything else i would need so that pretty much leaves me at $450 for the sub and amp. I have narrowed down the sub to a Stereo integrity HT 18" Dual 4 Ohm?, in a sealed cabinet. I'd like build something very similar to this build if not nearly identical. I really do not have the space for anything larger than a 24" cube, so would that build fit what i'm looking for? I also need some advice on an amplifier, the BehringeriNUKE NU1000 seems like it would fit the bill perfectly at $200. As for that amp, would i need the DSP version that is $100 more? So basically any input or suggestion will be greatly appreciated.

Thanks
 

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Yeah, you'd want to pull the most power possible to get bang for the buck on your amp. D2 would be the way to go.

If you have a decent size room that's open to the rest of the house, a sealed sub is usually not the way to go. However, considering your size constraints you could probably pull it off with the NU1000DSP. The EQ and strong amp would be key in making the sealed sub fill in the bottom end down to 20 Hz in an open environment. The problem with boosting LF is that you run our of amplifier headroom FAST. Around 4 cuft net volume, fully stuffed, would do for the 18 D2. That'd be roughly a 20" cube, maybe a little bigger depending on how much bracing you use.

The alternative would be to go with something like a 15 D2, vented. It would work in 5.5 cuft net tuned to 22 Hz with a 20 Hz HPF. It'd need the equivalent of three flared 4" round ports at a minimum. You could use the DSP amp for a 4th order HPF at 20 Hz, and use the EQ for room correction. This route is my suggestion over the sealed 18.

Here are both, the 15 D2 vented [green] is the clear winner over a 18 D2 sealed [blue] with EQ (amp power limited with 600W, +4.5 dB @ 22 Hz Q=1.0).
 

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Discussion Starter · #4 ·
Could you please upload the WinISD file for the 15" you modeled? I'm not getting the same results as you, granted i'm just learning how to use the program... So if i go with the 15" i would rather build a slotted port than use 3 4" cylindrical ports, therefore the port volume would have to be at least 1330" cubed correct? And is the port volume included in the total volume of the cabinet? When you said "20 Hz HPF" Is this a setting in the NU1000DSP amp or is there another product i need to purchase for high pass filter setting? Lastly and probably most import for me is how would this build compare to my current klipsch KSW-12 sub?

Thanks again
 

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The NU1000DSP will do a 48dB/oct 20Hz HPF for you. Yeah I'd agree that building a slot port would be a good way to go, it's up to you. Either sub will completely blow away the Klipsch KSW-12 (which is essentially a 100W ported 12" in <2cuft). Be sure and play around with box dimensions and port sizes to make sure you get the volume right! :T

http://www.hometheatershack.com/forums/enclosure-volume-calculator
 

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Fusseli, I checked out your SI 18 file. Are you sure you have the correct parameters for the driver?
I used measured parameters from http://www.data-bass.com/data?page=driver&id=46, and also note that box Q was adjusted to simulate stuffing and PEQ and applied amp power were adjusted to push the driver and amp to their respective limits. I re-entered everything again and uploaded the file again to be sure something wasn't missed.
 

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Looks like this woud be a good alternative to the SI 18 sealed build I was looking at. What kind of design criteria should one consider in doing slot ports? Minimum demensions, flares etc?
 
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