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Discussion Starter · #1 ·
I wanted my opening line to be " I just ordered two Incriminator Audio modded Death Penalty 21's" or " I just ordered two Maelstrom-X 21's" but I haven't heard back yet, so I am jumpin the gun a little, but here goes the beginning of the mod. The initial goal was to get two of the largest drivers with the most Vd, Fi Audio IB3 22's that are supposed to have 96% of the Vd of two IB3 18's, put them in the largest enclosures possible keeping it simple with 4'x8' sheets of MDF without joining pieces together. So the towers are 4'x4'x8' with a 12" port 5" long for about a 13Hz tune. I was running a pair of 18's temporarily at 8 ohms (custom dual 4 ohm coils) until th 22's came out then get dual 2ohm coils and run the 22's at 4 ohms. I want the lowest Q I can get with the largest single driver to get as much of a natural peak from 20Hz on down.


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Discussion Starter · #2 ·

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Discussion Starter · #3 ·
out with the old, those will get reconed for the VAN





 

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Discussion Starter · #5 ·
I was very pleased with the 18's should only get a touch better with 21's



Only problem besides electrical to back up current draw was the woofers causing the baffle to flex around the drivers but I'll be fixing that.
 

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Jordan,


Just a quick mention a 12" port 5" long with the 21" driver at 2000 watts input will give you a port velocity off 54 m/s max which is really high.


2 12" ports 19" long reduces it to 26 m/s and has a port resonance still off 350hz.


Just something to think about.


cheers


Graham
 

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Discussion Starter · #7 ·
Thanks Graham, I commented on that under the Collo: port too short tests? thread. The larger the port the higher the acceptable airspeed. Guess we will find out, may have to make some bells!
 

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Discussion Starter · #9 ·
Neither are answering back
 

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4 IB3's with 2 in each cabinet model the same as 2 21" malx's in the same cabinet. The input power is 2000 watts.


Why don't you stick 4 IB3's in each 128 cu ft box with 2 ep4000's. 1 ep4000 to 2 off the drivers and another ep4000 to the other 2 drivers in each box.


time that by 2 for both boxes and you get 124db at 10hz.


Apply that to a two sealed boxes with 4 IB3's in each box with 2000 watts to each box you get 104db at 5hz. Ported you only get 92db at 5hz. You still get 100db at 3hz.


I would say if you want 15hz and down to 5hz then ported will loose below 10hz. Sorry I said that.


You could easliy by the IB3's you need to match the cost on the malx's.

I know what I would do.


cheers


Graham
 

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Discussion Starter · #11 ·
From the " Two Towers, Two 22's, or MX21s? " thread

Quote:
Originally Posted by kryptonitewhite /forum/post/19555901


My intentions for my Two Towers was initially Fi IB3 22's. 96% of the Vd of double the IB3 18's. I wanted the largest displacement driver possible for the projected $450 price tag. I wanted to build the largest enclosures possible per driver for the lowest Q and lowest tune possible with the largest port. The FR plot for the 18's is exactly what I want. Flat to 20Hz then a HUGE spike from 10-20Hz. I have been hoping the 22's would plot similar but louder, more displacement.


Well I need something now. I have been waiting 2 years for the 22's and Ive given up. I don't want to simply add 2 more 18's because that messes up my Q per driver, messes up my FR. I want the same but more.


Going from the 18's to the 22's shouldnt be a huge difference, double the VD but not double the Xmech. I push my IB3s to the full 41mm all the time and I cant hear it when I pass Xmax. So even though the 22's have double the VD cause theyre supposed to have 38mm Xmax vs the 18's 30mm, they have the same Xmech, same profile surround, so I won't have double the useable excursion. So already changes with 22's may only be marginal.


So Nick at Incrimiator is willing to build me custom 21's for $450. PLEASE no one assume they can get them for that, this was a personal talk a long time ago. Do not quote me. He would be using the Death Penalty motor with a softer suspension. I don't think very much Xmax, and I have no idea about parameters. So going from a 22" cone with 30mm Xmax down to 21" cone with less than 30, no good, especially for the same cost.


At one time I was able to get 21" Maelstrom-X's for $450, but it was too late. Again, do NOT quote me on that, that was special circumstances and has now passed. Going from 22" to 21" makes a difference. Period. 1" wide 21 inches around is a good amount of cone area. On top of that, its a flat/wide surround that I HATE rather than the tall 1/2 roll profile of the IB3s. 32mm is OK.



I decided to plot the 21's vs the 18's and I dont like it. Just like all the plotting I did in my van comparing "better" drivers to the IB3s, the larger motored drivers have the same issue in so much airspace: Huge spike at tuning, good, but a huge dip after, then climbs back up.




Overall the 21 is much louder though, as expected, and it would be popular cuz who doesnt love this driver




I been asking about having to bump up to 20" ports for the 22's, well they have more displacement that the 21's and the 21's getting out of hand with *only* 12"



 

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Discussion Starter · #12 ·
From the " Two Towers, Two 22's, or MX21s? " thread

Quote:
Originally Posted by kryptonitewhite /forum/post/19560184


the plot for adding more 18s is nasty, counter productive. same 20Hz on down but sky rockets from 20Hz on up, opposite of what I want.





 

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Discussion Starter · #13 ·
I will reitterate: I think people go overboard on bracing sometimes, I feel people get too concerned with port resonances, panel resonances, decay, little peaks and dips, imaging, yadda...I'm no SQ guy, I am a sloppy lazy guy. I have seen so many boxes with panels less than 2'x2'x2' with a **** ton of bracing. Good for them, props to them, I won't hate. I will not argue that it is not effective. It looks badass, it makes things solid, ridgid. It makes your enclosure perform closer to the predictions by minimizig losses. I am all for it. But it is NOT me. Furthermore, I have 4'x8' panels with only a single center brace and I:


Barely suffer from pressure flexing! The only flexing issue that I have is the driver force itself flexing the baffle. It is only a serious problem by the drivers. The bottom 1/2 of the baffle seems to suffer a touch from the ports, but the side panels do not have the problem.


Because of this, I am putting braces in the 4 corners of the subs, this should also help support the large drivers weight that is centered so far back. Then 2 more braces on the upper corners of the ports. Front to back.





 

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looking good so far man, but I still think the 21's will not be enough for you. "no g spot note here, move along please."
 

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Discussion Starter · #15 ·
I think I need a 40" with a parthenon motor
 

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I'm just re-establishen, that there aint no such thing as WAY too many pointless pics.


I've enjoyed your videos, some a bit long and monotonous, but whatever. I've enjoyed your pics, keep 'em coming.


Good luck with the retro-fit and rock on
 

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Discussion Starter · #17 ·
Quote:
Originally Posted by FOH
I'm just re-establishen, that there aint no such thing as WAY too many pointless pics.


I've enjoyed your videos, some a bit long and monotonous, but whatever. I've enjoyed your pics, keep 'em coming.


Good luck with the retro-fit and rock on
It's post like that that make it worth my time! Hope to have some driver pics and vids soon! Thank you
 

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Only two??? make it more like 12! two might get lonely.
 

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Discussion Starter · #19 ·

Quote:
Originally Posted by s_carter /forum/post/19594721


just one of those for the HT and one of those for the van and Id be happy. Hell, a 40" driver with a ton of Xmax and Id never have upgradeitis again. Nah, wait, if I had 12 instead of one I could get down to xHz



this truely is a sickness
 

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I can totally see my first house being built entirely of speakers. Who needs a vacuum when you can just blow all the dirt out of your house?
 
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