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Discussion Starter · #1 ·
I'd love to be the first, but budget and (limited) space are making me think the 18" is going to be for me.

I'd love to live vicariously through some 21" build threads though!!

Who knows, maybe someone can talk me into building a 21, for better or worse. :sn:
 

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Discussion Starter · #5 ·
Two 15'³ sealed boxes........at least at the moment. I'm still trying to finalize the size of the boxes and what amp I'm gonna use......
That's exactly what I was considering building, but others have suggested a ported 18" of the same size would outperform a sealed 21". I am not yet skilled enough with WinISD to hash that out for myself. Back when I was building subs (going back 15-20 years) we didn't have all these cool tools and knowledge available.
 

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That's exactly what I was considering building, but others have suggested a ported 18" of the same size would outperform a sealed 21". I am not yet skilled enough with WinISD to hash that out for myself. Back when I was building subs (going back 15-20 years) we didn't have all these cool tools and knowledge available.
The sealed 21" rocks..... I'd ignore the "others". ;-)

I have a customer building a pair of ported 21"s for electronic organs. It is a large cathedral so they have to move some serious air to hit their 16Hz objective (lowest note on their electronic organ).

I'll see if he will post some pictures and notes.

Kevin Haskins
Exodus Audio
 

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Discussion Starter · #9 ·
The sealed 21" rocks..... I'd ignore the "others". ;-)

I have a customer building a pair of ported 21"s for electronic organs. It is a large cathedral so they have to move some serious air to hit their 16Hz objective (lowest note on their electronic organ).

I'll see if he will post some pictures and notes.

Kevin Haskins
Exodus Audio
You sure you're not just trying to upsell me?! :wave::D

Do you have plots for 18" ported vs 21" sealed with the power of an EP2500 behind it?
 

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Can't wait for the build threads to start, this is going to be a lot of fun to watch from the side lines.
 

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I should have a thread soon...........plans are two Mal-21's in two large sealed boxes.
Who would have ever thought dual Mal-X 18's in sealed boxes would feel so dejected so soon:hissyfit:

I think the boxes for a pair of 21's would be too big for me though but I could always keep hope alive.

Can't wait for your build thread.......got keep feeding the addiction:help:
 

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Pretty excited to see some of these 21 monster takeshape.

I was real close to attempting a submersive type build with the 21s; however just bought a new house and this will have to wait.

Lets get'r done!
 

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Re:New build with Maelstrom-X 21" with 4 18" 2100 gram passive radiators

vongerv

Here's one! I'm using Kevin's Maelstrom 21"er with the passive radiator design. I normally don't like building a passive radiator sub with a Qts over .4, but it is so close, I won't have a problem.

Here's the deal....23" x 23" x 60"; 13 cubes and 15.5 hz box tuning. Throw in a dash of room gain and the numbers drop. With the typical passive radiator design there is more of a roll off, but at this tuning I'll have more than plenty of bass. I needed the height to get the required volume and it will match my main speaker's height. Better WAF here.

I just picked up the pallet of materials from my mill. My construction material is 1.25" mdf. It looked like I had ten bags of concrete in my truck going down the road. Cabinet resonance with this thick material; I don't think so. Moving it? Now that's another challenge.

Just got back from Houston with the materials so here is the first build pic::wave:

Update: I've just started a new thread for my build.
http://www.hometheatershack.com/for...800-gram-15-passive-radiators.html#post208516
 

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Discussion Starter · #16 ·
Re: New build with Maelstrom-X 21" with 6 15" 1800 gram passive radiators

vongerv

Here's one! I'm using Kevin's Maelstrom 21"er with the passive radiator design. I normally don't like building a passive radiator sub with a Qts over .4, but it is so close, I won't have a problem.

Here's the deal....23" x 23" x 60"; 10 cubes and 17.5 hz box tuning. With the typical passive radiator design there is more of a roll off but at this tuning, I'll have more than plenty of bass. I needed the height to add the three passive radiators on each side and it will match my main speaker's height. Better WAF here.

I just picked up the pallet of materials from my mill. My construction material is 1.25" mdf. It looked like I had ten bags of concrete in my truck going down the road. Cabinet resonance with this thick material; I don't think so. Moving it? Now that's another challenge.

Just got back from Houston with the materials so here is the first build pic::wave:
Awesome! I can't wait to see your thread on it!

If all goes well, I should be firing mine up tonight!
 

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What size sonotube would you need for these 21"er. Diameter and length needed, Kevin?

Where would one find these large diameter sonotubes in Ohio? I have a QSC PLX3402 sitting around I could power two of them with, maybe?
 

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What size sonotube would you need for these 21"er. Diameter and length needed, Kevin?

Where would one find these large diameter sonotubes in Ohio? I have a QSC PLX3402 sitting around I could power two of them with, maybe?
You would probably want to go 24", just so you have some space around the driver for feet. You have to go to the local lumbar yard or contractor suppliers. The place that orders them in my neck of the woods is the sand/gravel/concrete business. They are concrete forms, so that is the type of business that will carry them. Get out the Yellow Pages and let your fingers do the walking.

Kevin Haskins
Exodus Audio
 

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Discussion Starter · #20 ·
I was actually wondering the same thing. I have about 26" between the screen and the floor, and my mains are about 24" from the wall.
 
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