# The Maelstrom-21" BASS! HOW LOW CAN YOU GO?



## WLDock

OK, I have a true bass head friend that had been into bass for at least a decade and a half or two When he got a new Chevy Avalanche years ago (Around '03-'04) he put a BIG system in it with a P9 combo, 3-way front w/ 8" midbasses, and ALL JBL in back with a couple of 500 watt 4 channels, a JBL/CROWN BPX2200.1', and three W12GTi subs ported. That system was loud as hell and was waaay more then I could take as I was getting lightheaded during an open listening session...and the system was not at full tilt.* My bud comes to me for advice on certain equipment and will go out and get it if he thinks it will work for him.* The W12GTi's , P9, Dayton RS225, Max Fi, etc are some of the gear that I recommended.

OK, moving forward....I remember seeing a big sale on JBL amps and told my bud.....*and of course he checks it out and picked up ANOTHER CROWN 2200!* I don't know what he planned to do with it but he got it. Later, he was looking around for different subs and I suggested a couple of W15GTi's. Somehow we got on the topic of LARGE subs and I told him SOUNDSPLINTER makes and 18" sub, the RL-p18. *Low and behold.....he bought the sub!*

He says that the RL-P18 hits harder and cleaner than the 2 W12GTi's....if you can believe that. He says that the enclosure just moves all over the place and he is scared to bolt it down as it might really do some damage. The sub actually blew the bottom of the enclosure apart and even blew itself out of the enclosure. The last incident....*the sub tore the cone off the coil!*

Around the time my bud was considering sending the RL-P18 in for repair here recently I told him about the DIY CABLE Exodus Audio *Maelstrom-21" sub*. He was VERY interested but said he was trying to repair the 18" with some JB Weld but would look into the 21"

Well.........He repaired the 18" and said it hit just as hard and clean as when it was new.* Pictured here in a 5 cu ft sealed enclosure!*:









However, he said he was still after something new and indeed bought the *Maelstrom-21" sub*! But wait....*he did not buy just one Maelstrom-21" sub....the old school bass head friend of mine BOUGHT TWO Maelstrom-21" SUBS SO THAT EACH JBL/CROWN BPX2200.1 HAS A SUB TO POWER!!!!!* WTF?

A "true" heavyweight hitter indeed. He stopped by one night to show me one of the subs and we talked about how robust the enclosures are going to have to be. Here are the pics:

21"!!! Adult bass!









The Maelstrom-21" next to the SOUNDSPLINTER RL-P18"









The 21" side side with a huge JBL W12GTi...bird's-eye view:









The W12GTi has to be the largest 12" that I know of....









The powerplant that will be used for the upcoming build...two Kicker 4 channels and about 4000-5000 watts of CROWN power!









Stay tune...I will post the build when he saves up enough pennies to pay for wood for the enclosures.



*



The big brother for the Maelstrom-18", the MAELSTROM-21"!!!! The Maelstrom-21" isn't just one of the world's highest output subwoofers, it is a bargain too! Displacing nearly 10L of air, it has the raw output capability to outperform subwoofers costing many times it's humble price.

Deep bass is all about moving air and most companies use 12" or 15" subwoofers in their top-of-the-line products. A 12" driver, typically has around 490-500 cm^2 of surface area, and a 15" around 800 cm^2 of area. The Maelstrom-21" has a simply massive 1550 cm^2 of surface area being swept through up to 66-70mm of two-way throw. That is enough swept area to CRUSH the top of the line subs from some of the biggest names in audio and home theater.

But the Maelstrom-21" isn't just about output, it is a balanced design that is musical and can reproduce the smallest nuances in bass reproduction. This is a state-of-the-art product, that is brought to the market at realistic prices. You don't have to dream about that statement product, you can now permanently end your upgrade fever. The Maelstrom-21" is the last subwoofer you will ever need to purchase. Feel free to contact our engineering and support team for advice on how to build your final subwoofer, the Maelstrom-21".

Kevin Haskins 
Exodus Audio

Click to expand...

*


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## mmiller

Does your friend have a hearing Aid??? LOL...

That dudes Crazy!


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## miniSQ

I'm sure your friend ha seen this but for the others...42" of woofer porn....

*****The 42's: Maelstrom 21" sub box (NEO Dan design).....dual box build***** - AVS Forum


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## WLDock

miniSQ said:


> I'm sure your friend ha seen this but for the others...42" of woofer porn....
> 
> *****The 42's: Maelstrom 21" sub box (NEO Dan design).....dual box build***** - AVS Forum


I don't know if he has? i will forward it to him. thanks man!


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## WLDock

I showed him the link....I think he plans to use about half the cu ft for his in vehicle install.


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## miniSQ

He should try and get in touch with Kevin Haskins at EA to see about box size...but half sounds about right.


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## cubdenno

cajunner said:


> 21's are too slooooow...


BWA HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!:laugh:


Tru Dat!


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## 60ndown

cajunner said:


> 21's are too slooooow...


naw mang, you can get em great with a *faster* signal.

21s play 35hz real good if you send em 38 hz. :blush:


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## fish

The surround on that thing is massive next to the JBL 12".


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## Electrodynamic

The surround on those 21's are pure sex.  

...and the guys on the AVS forum's are NUTS (just the way I like it)!! Talk about wanting tons of bass in a living/listening room!


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## da Vinci

I'm quite interested to see where this goes. I have been reviewing the differences between some of these large format, high excursion linear motor subs such as the XBL^2 in the Maelstroms, LMS from TC Sounds and Differential Drive from JBL. The price point is great on the Maelstroms, however without seeing one or having someone to reference, I wasn't sure how the Maelstroms foam surrounds would hold up to Michigan weather in a vehicle. Basically all three subs I have been looking into have drawbacks. The maelstroms with the foam surround, the JBL's with the odd voice coil resistance, and the LMS Ultra is just expensive. 

Out of curiosity, where are the Maelstroms assembled?


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## fish

Da Vinci, regarding the JBL, what are you using for your sub amp?


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## da Vinci

fish said:


> Da Vinci, regarding the JBL, what are you using for your sub amp?


I have two McIntosh MC443 at the moment. I probably will use those for midbass though, and end up getting a Kicker 10ZX2500.1. I am aware that I can run 3 of the WGTi to get to a 4 or 1 ohm(not big on running this low) load. I also know 3 would be sufficiently powered by the Kicker amp at 4 ohms. But with three 15's comes added weight. If I do use the two MC443, I can run each VC on a Maelstrom or LMS Ultra with one amp. If I use the 10ZX2500.1, I'll get about 1500 watts at 4 ohms. I could also run two W15GTi, one to each MC443 and they would get about 500 watts being that the 443's are rated with 1db of overhead.

Mind you, I'm going for linear displacement, not spl(although i'm sure I'll get plenty)... so I don't plan on running whatever I go with full tilt. I've just been looking to try something new and am leaning towards one of these setups.


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## DS-21

da Vinci said:


> I'm quite interested to see where this goes. I have been reviewing the differences between some of these large format, high excursion linear motor subs such as the XBL^2 in the Maelstroms, LMS from TC Sounds and Differential Drive from JBL. The price point is great on the Maelstroms, however without seeing one or having someone to reference, I wasn't sure how the Maelstroms foam surrounds would hold up to Michigan weather in a vehicle. Basically all three subs I have been looking into have drawbacks. The maelstroms with the foam surround, the JBL's with the odd voice coil resistance, and the LMS Ultra is just expensive.


I wouldn't consider the foam a drawback, or the JBLs voicecoil resistance. What I would consider drawbacks are the relatively weak motor (by comparison) and highish inductance on the current-gen Maelstrom (especially the 21, which just needs too much box to be useful IMO), and the mounting depth of the JBL GTi.

I've used most of the "high excursion linear motor subs" by now. For a while and for maybe a week or two more I've been running a Maelstrom-X Mk. I (dual 4Ω coils, 0.87mH Le) in my nearfield home system. (I'm replacing it with an Aura NS18. And yes, it will be for sale.) Before that, it lived in my main home system from new, where it replaced a more primitive "high excursion linear motor sub," an Ascendant Avalanche-18. It displaced a JBL W15GTi-based sub in the nearfield system. The main system is all Aura on the floor - an NS15 and two NS12s - with the high-mounted sub soon to be an NS10.

My honest opinion is that they're so close in performance that it's basically impossible to tell them apart in listening. Except for the Ava18, which was a clear step down from any of them. (Why? Simple: no shorting rings in the motor.) 

So, why the changes? Basically appearance, to be honest.



da Vinci said:


> Out of curiosity, where are the Maelstroms assembled?


The Maelstrom, like the TC Sounds LMS*, Aura NS-series (the ur-linear motor type, underhung, but with the new twist of the neo radial magnets), and possibly but I'm not sure the JBL GTi (Harman has or is in the process of closing down its Northridge plant, so all JBL home, car, and Pro speakers will be made in Mexico or Asia), is made in China. The Maelstroms might actually be _assembled_ in the US. I vaguely remember Kevin once writing about them being shipped to him in two pieces and assembled by him in WA, but that could be wrong.

*technically, the final assembly step for the LMS/LMT woofers occurs in the end-user's home, because they are (I believe) shipped as a separate cone-assembly and a motor-unit. Which, considering the mass of the motor, makes great sense. Probably many fewer shipping losses that way.


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## da Vinci

DS-21 said:


> I wouldn't consider the foam a drawback, or the JBLs voicecoil resistance. What I would consider drawbacks are the relatively weak motor (by comparison) and highish inductance on the current-gen Maelstrom (especially the 21, which just needs too much box to be useful IMO), and the mounting depth of the JBL GTi.
> 
> ...
> 
> The Maelstrom, like the TC Sounds LMS*, Aura NS-series (the ur-linear motor type, underhung, but with the new twist of the neo radial magnets), and possibly but I'm not sure the JBL GTi (Harman has or is in the process of closing down its Northridge plant, so all JBL home, car, and Pro speakers will be made in Mexico or Asia), is made in China. The Maelstroms might actually be _assembled_ in the US. I vaguely remember Kevin once writing about them being shipped to him in two pieces and assembled by him in WA, but that could be wrong.
> 
> *technically, the final assembly step for the LMS/LMT woofers occurs in the end-user's home, because they are (I believe) shipped as a separate cone-assembly and a motor-unit. Which, considering the mass of the motor, makes great sense. Probably many fewer shipping losses that way.


The thing is, where I live in Michigan, it is constantly VERY humid (I live right by the great lakes after all... 5 miles from the water). In the spring, and toward winter, there are many nights where the interior of my car is covered in condensation. On a bad night, it all freezes. If that Foam surround is at all scratched or compromised in any way, that water will get in there, expand when it freezes, and deteriorate the surround. I'm an installer, and I have seen many foam surrounds fail whether it was from moisture or from UV damage. So needless to say it worries me. That sub wasn't designed to be primarily used in a vehicle after all. As far as box space for the Maelstroms... not an Issue. I drive a Focus Hatchback, and have removed the rear seats. As far as I am concerned the box will take up the entire rear of the car. I also am concerned with the motor however, but am taking the approach that they know more about speaker design than I do.

As far as the JBL's, its not really the VC resistance as much as it is the fact it leads me to need to run 2 or 3 of them to get what I am after... and that is more weight (and possibly money) than I want. I also don't want to run down at 1.5 ohms, and to run at 6 I would need an insanely large amp just to power them properly. If it wasn't for that they would probably be my first choice.

It's going to be a while before I dive in, as the sub is going to be the last phase of my install. By then i'll probably have saved enough to take the plunge on whatever... just need to research more.


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## T3mpest

da Vinci said:


> The thing is, where I live in Michigan, it is constantly VERY humid (I live right by the great lakes after all... 5 miles from the water). In the spring, and toward winter, there are many nights where the interior of my car is covered in condensation. On a bad night, it all freezes. If that Foam surround is at all scratched or compromised in any way, that water will get in there, expand when it freezes, and deteriorate the surround. I'm an installer, and I have seen many foam surrounds fail whether it was from moisture or from UV damage. So needless to say it worries me. That sub wasn't designed to be primarily used in a vehicle after all. As far as box space for the Maelstroms... not an Issue. I drive a Focus Hatchback, and have removed the rear seats. As far as I am concerned the box will take up the entire rear of the car. I also am concerned with the motor however, but am taking the approach that they know more about speaker design than I do.
> 
> As far as the JBL's, its not really the VC resistance as much as it is the fact it leads me to need to run 2 or 3 of them to get what I am after... and that is more weight (and possibly money) than I want. I also don't want to run down at 1.5 ohms, and to run at 6 I would need an insanely large amp just to power them properly. If it wasn't for that they would probably be my first choice.
> 
> It's going to be a while before I dive in, as the sub is going to be the last phase of my install. By then i'll probably have saved enough to take the plunge on whatever... just need to research more.



The one ohm difference on the JBL's won't make a massive difference in power from the amp, at least not anythign super audible or worth losing sleep over. What part of the Maelstroms motor bothers you?


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## da Vinci

T3mpest said:


> The one ohm difference on the JBL's won't make a massive difference in power from the amp, at least not anythign super audible or worth losing sleep over. What part of the Maelstroms motor bothers you?


Seems a bit small for a 21" woofer. Like I said, I've taken the approach that the designer knows more about it than myself.


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## DS-21

da Vinci said:


> I have seen many foam surrounds fail whether it was from moisture or from UV damage. So needless to say it worries me. That sub wasn't designed to be primarily used in a vehicle after all.


There are many types of foam, and most car-fi-intended speakers tend towards the cheaper varieties.

As to suitability for your application and climate, why not just e-mail or call Kevin and ask? He's a very straight shooter? He knows the details of the parts he's specified better than most end-users.



da Vinci said:


> As far as box space for the Maelstroms... not an Issue. I drive a Focus Hatchback, and have removed the rear seats. As far as I am concerned the box will take up the entire rear of the car. I also am concerned with the motor however, but am taking the approach that they know more about speaker design than I do.


The only "problem" with the motor is that it makes the sub require a huge box, because it's kind of weak. If that's not an issue for you, then it's a non-issue. (Though I can't imagine why anyone would willingly waste all of the available cargo volume in her/his car on speakers. But that's just me.)



da Vinci said:


> As far as the JBL's, its not really the VC resistance as much as it is the fact it leads me to need to run 2 or 3 of them to get what I am after...


What does that even mean? People worry too much about impedance. Not getting every last possible watt out of a given amp is, believe it or not, not even a sign towards the end of the world. A 6Ω sub will do just fine in most applications. The worst thing you will notice is that your amp will run a bit cooler than a more loaded-down one. And that's a huge problem! After all, who wants to prolong the life of her/his amp?


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## laxcat73

DS-21 said:


> What does that even mean? People worry too much about impedance. Not getting every last possible watt out of a given amp is, believe it or not, not even a sign towards the end of the world. A 6Ω sub will do just fine in most applications. The worst thing you will notice is that your amp will run a bit cooler than a more loaded-down one. And that's a huge problem! After all, who wants to prolong the life of her/his amp?


I laugh anytime someone mentions the impedance thing as a huge issue - they usually want lower impedance to get the most out of a given amp. :laugh:


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## new2mobile

what kind of spl could one expect from that driver in a 5ft cube sealed with 1000 watts?


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## t3sn4f2

new2mobile said:


> what kind of spl could one expect from that driver in a 5ft cube sealed with 1000 watts?


I think that enclosure size is one of the enclosure examples in the manual.


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## da Vinci

laxcat73 said:


> I laugh anytime someone mentions the impedance thing as a huge issue - they usually want lower impedance to get the most out of a given amp. :laugh:


I don't see what's so hard to understand about it. I am not a fan of running any load lower than 4 ohms. I have two McIntosh MC443 that I have had since 1997, still run perfect. I have a Kenwood KAC-1021 from 1991 that still has no problems. This is because I do not ask the world of them, and they have always been set to avoid clipping. That being said, one of those amps at 6 ohms would be about 225-300 watts considering they were rated with 1db of overhead. Do either of you suggest I run two 15's sharing that much? I could run them 1 to each amp at 3 however and it would work great.... except for this overhaul I plan to use those amps for my midbass section. Now taking a look at modern sub amps, they are almost all rated for 2 or even 1 ohm... not a fan. So I can buy a huge amp... one I have available to me at a very good price is the Kicker 10ZX2500.1... and run it at 4 ohms and still get about 1500 watts out of it. That is how I would want to run that amp. If I run that amp at 6 ohms i would get roughly 1125 watts. Thats good enough to run two of those... absolutely... but that's a lot of money to get 1000 watts... when with normal speakers I could spend half that much. All this is looking past the fact that I already run two 15's and am looking for more LOW output. That leads me to getting three WGTi and giving them 500-600watts each just to reach those lows. Three WGTi is also the heaviest of the options. It's absolutely NOT about squeezing every watt out of an amp... but it does have to be an acceptable (to me) amount.

You guys are making a bigger deal of it than I am anyway... its still one of my options... it just requires more consideration than others when it comes to the amps that I have available to me and how much weight I add to my car. It will also cost the most. That is why I called it an inconvenience. In the end when I make my decision, it's going to be based purely off which I think will perform the best for me... price, box size and weight be damned.

All that is a ways off, and I have a lot of research to do. I wont be buying any of this until its ready to be put in... I don't want it sitting around my house. For now I'm concerned with getting my carputer in the car as well as getting the front speakers put in which will be a lot of fiberglass work. One thing at a time... research as I go.

Back on topic now? I'm interested because the OP doesn't live far from me... I'd like to hear his impressions how it holds up to our weather. I realize there are different foam surrounds... but I've never seen a Maelstrom in person so I can't judge it. Maybe it's super high quality. I don't know that yet. Although I do plan to email diycable, I don't know anything about him to 100% trust a sales person(and I don't trust people in sales). So it doesn't hurt to hear the opinion of someone in my area. People who are not from this area don't understand just how humid it gets here.


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## new2mobile

t3sn4f2 said:


> I think that enclosure size is one of the enclosure examples in the manual.



it is , but I don't get the application notes too well (because i royally suck at this, lol)

from what I understand the in room and cabinet graph peaks at around 120db at 40hz, but I'm not clear on the power required and what cabin gain would add to that 120


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## T3mpest

new2mobile said:


> it is , but I don't get the application notes too well (because i royally suck at this, lol)
> 
> from what I understand the in room and cabinet graph peaks at around 120db at 40hz, but I'm not clear on the power required and what cabin gain would add to that 120


another 10-30db's depends on the car. A 21 is like having 2 15's or 3 12's if that gives you any idea.


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## DS-21

da Vinci said:


> This is because I do not ask the world of them, and they have always been set to avoid clipping. That being said, one of those amps at 6 ohms would be about 225-300 watts considering they were rated with 1db of overhead. Do either of you suggest I run two 15's sharing that much?


Why not? It would be worth a try, especially if they're in large enclosures or mounted I-B. Small sealed, probably not.

Of course, the bigger question is whether one needs two fifteens. One W15GTi can do a helluva lot. 



da Vinci said:


> Now taking a look at modern sub amps, they are almost all rated for 2 or even 1 ohm... not a fan. So I can buy a huge amp... one I have available to me at a very good price is the Kicker 10ZX2500.1... and run it at 4 ohms and still get about 1500 watts out of it. That is how I would want to run that amp. If I run that amp at 6 ohms i would get roughly 1125 watts. Thats good enough to run two of those... absolutely... but that's a lot of money to get 1000 watts...


Don't think in terms of watts, think in terms of output. Download Unibox and plug in some numbers. You'll find the actual differences are quite low. Especially on a sub with such good thermal properties as a W15GTi.

At _home_ in my nearfield system for a while I ran a W15GTi in a ~4.5 ft^3 sealed box off of an NHT A1 monobloc, an example of which was measured here. It was good for maybe 375W into the 3Ω impedance of the driver. And yet, it did just fine. It kept up quite well with my nearfield mains, 8" Tannoy Dual Concentrics of 90+ dB/w/m sensitivity powered by ~100W each. Yes, the Crown XTi2000 (run in stereo for 800W per vc, 1600W total) that eventually supplanted the NHT amp sounded much better. But the vast majority of that improvement was due to the parametric EQ that allowed me to address some pesky room modes.

So obsessing about power is generally speaking a waste of time.



da Vinci said:


> when with normal speakers I could spend half that much. All this is looking past the fact that I already run two 15's and am looking for more LOW output.


Well, a _better_ 15 in the right-sized enclosure might be enough for you. Perhaps your current ones aren't in the same class, or your box design is suboptimal. ("Recommended" box sizes are not designed for fidelity, but to prevent warranty claims.)


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## da Vinci

> Why not? It would be worth a try, especially if they're in large enclosures or mounted I-B. Small sealed, probably not.
> 
> Of course, the bigger question is whether one needs two fifteens. One W15GTi can do a helluva lot.


I want to be able to drop the knob on occasion. Aside from that, I would much rather turn down the gain or bands on the EQ than up. I'd rather have too much and run it slightly underpowered than push too little into distortion. Also... this install is somewhat of a "go big or go home" type thing as I am trying to build my portfolio. I've always been very private about my installs in my own car and my friends... kind of stealth approach. Unfortunately there's not much to see or take pics of doing that... so I never did aside from a few door pods. I've been on interviews and they wanted to see more. It's never been my bag of chips, but like I said... it's time for something new... I think this install will be fun... something car audio, for me, has not been in a long time.



> Don't think in terms of watts, think in terms of output. Download Unibox and plug in some numbers. You'll find the actual differences are quite low. Especially on a sub with such good thermal properties as a W15GTi.


You know, I downloaded Unibox years ago... and I don't think I've ever used it(maybe didn't understand it back then). I'll have to do just that. Maybe I'll learn something I didn't know when I do... in fact I'm sure of it. I still have a lot to learn when it comes to speaker parameters and box modeling. I've been pacing my way through the Loudspeaker Design Cookbook... unfortunately much of it goes over my head. I'm looking to change that.


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## Hispls

60ndown said:


> naw mang, you can get em great with a *faster* signal.
> 
> 21s play 35hz real good if you send em 38 hz. :blush:


^^^^ True dat. 

:laugh:


That's a monsterous looking driver.


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