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Discussion Starter · #1 ·
Hello guys,

I was curious i really liked the box that dan created and i was wondering if i can replicate this for an Fi Q 18

http://www.hometheatershack.com/forums/exodus-audio/12134-my-sealed-maelstrom-x-build.html

Im planning on using the box mainly for music but also for movies and games occasionally but 98% of the time MUSIC

Thanks, i just want ot know what i gotta do to make it work for an FI Q 18 thanks

Q18

DUAL 1 | DUAL 2

Fs: 24.5 Hz | 23.8 Hz
Re: 0.7 Ohms/coil | 1.4 Ohms/coil
Qms: 5.66 | 5.73
Qes: .64 | .63
Qts: .58 | .57
Mms: 322g | 342g
Cms: 0.13mm/N | 0.13mm/N
Sd: 1210cm^2 | 1210cm^2
Vas: 268 l | 268 l
Spl: 89.7dB 1W/1m | 89.4dB 1W/1m
Bl: 10.4 N/A | 15.1 N/A
Xmax: 27mm
Rms: 1000W
Sealed box: 4-8 cuft
Ported box: 6-10 cuft @ 28Hz
Sub OD: 18.500”
Cut ID: 16.750”
Mounting depth: 10.000”
Displacement: 0.24cuft
 

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Here is the WinISD download and a tutorial on how to use it.

http://www.hometheatershack.com/for...wnload-detailed-guide-how-use-winisd-pro.html

Here is the file for the Q18.

http://www.hometheatershack.com/forums/diy-subwoofers/14410-downloadable-winisd-pro-files.html


Model the Q18 in 6 cu.ft. sealed and see what you come up with.
just posted about that in the other thread, hadn't seen this yet.

but what he said... get to know thiele small paramters, get to know ISD
 

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I will admit that it was kinda hard to learn WinISD, but once you do, it's a breeze to use. You can input new driver's T/S specs without having to look at what order to put them in, and other stuff. Its a really helpful program once you lean how to use it properly. Just fool around with it for a while. After a while, you will just start modeling a bunch of other drivers in different box sizes, tunings, and other stuff, just to see what it would look like haha
 

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Discussion Starter · #7 ·
oK THERE we go well i read a Q of .5 was good is that true, and that was for a sealed enclosure with an 18, can some one shed some light?

Thanks,

KrazyBassKevin
 

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Discussion Starter · #9 ·
so if i added fiberfill to that box with .9 can i get it down to .7???

thanks i think .7 is ideal for me cause i play more music that i do Movies!

Thanks will that fiberfill work

KrazyBassKevin
 

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i have heard a full stuff = 10% volume added, so add 10% to your volume and plot again... someone correct me if I'm wrong, I've never stuffed... my subwoofer enclosures :)
 

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Discussion Starter · #11 ·
Thanks Ryan althought i just need the Q to go down from .9 to atleast .8 or .7 cause .9 is a little high i just was curious if the fiberfill would lower it

Thanks

KrazyBassKevin
 

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Discussion Starter · #13 ·
About how little are we talking about with fiberfill and what would be an option to lower it possibly to .7?

What kind of simply box changes would need to be made??

the box larger or smaller and by about how much?

Thanks,

KrazyBassKevin
 

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Kevin, I feel for you right now because I know I did the right think talking you out of the SPL burp monster BTL and into the HT ready Q driver.... you did the right thing. But now all a sudden it doesn't seem that way cuz you still need to build a large enclosure for it.

Well here is the deal. The larger you build an enclosure, the less springy it is, the less it has to fight. This lowers Q and raises efficiency down low. The lower the frequency plaid, the further the sub has to move ( 1/2 an octave means moving 4 times the air to maintain the same SPL ) so lower frequencies have to fight the "air spring" more. So the smaller a box is, the more it reinforces the high frequencies, but fights the lows.

The drivers Thiele Small Parameters also come into play. The Q will play much lower than the BTL in the same alignments. Youre still much better off with the Q, but, you still need to plot.

Mike does the plots around here... scoot him a PM or myself and I'll do some for you.

What amp are you using? Goals?
 

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Discussion Starter · #15 ·
Thanks Ryan for the help much appreciated,

Ok i have a Behringer ep4000, and i was thinking to make a 13 ft^3 box so making the box 30inches all around a basically a 30 inch cube with 2 braces with diameter of 18 in i got a Q of .750 somthing like that what do you think

Or a 40x40 inches thats like a 30 ft^3 which i think is way to big but it does hit .7 very low .7's but i like 30X30 inches cause its not to massive and i can add fiberfill to lower a tiny bit i think??

But hey Ryan what do you think i saw you last monster creation with the 15 that was nice sized, so if you can plot a 13ft^3 box that would be cool lets see if that changes the Q?

And another question about tuning the frequencies about how low is it going to be

Thanks a ton

KrazyBassKevin
 

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Thanks Ryan for the help much appreciated,

Ok i have a Behringer ep4000, and i was thinking to make a 13 ft^3 box so making the box 30inches all around a basically a 30 inch cube with 2 braces with diameter of 18 in i got a Q of .750 somthing like that what do you think

Or a 40x40 inches thats like a 30 ft^3 which i think is way to big but it does hit .7 very low .7's but i like 30X30 inches cause its not to massive and i can add fiberfill to lower a tiny bit i think??

But hey Ryan what do you think i saw you last monster creation with the 15 that was nice sized, so if you can plot a 13ft^3 box that would be cool lets see if that changes the Q?

And another question about tuning the frequencies about how low is it going to be

Thanks a ton

KrazyBassKevin
what 15? my signature is an 18" Fi IB3

I'm downloading driver data and firing up winisd now...post in a bit
 

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forgot i formated the other day, redownloaded isd and driver data, plotted Q in default vented, default changed to 13 cubes, 30 cubes, and against BTL defaulted, 13, and 30 cubes to show how much more you get from going with the Q. Then had trouble as BTL plots disappear even after rentering tuning. Then cant remember my photobucket password. Its late man, sorry, get to ya tomorrow!
 
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