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Discussion Starter #1
I've been enjoying my 21" DIY sub for 4 years now, but I've hit a problem.



The other day I was doing some rewiring in my audio rack and I think I accidentally turned up the gain on the ep4000 powering my sub. I was taking a shower with the system turned to the maximum I would normally turn it up to and when I went back into the living room there was a loud rattling sound coming from the driver. It wasn't a clunk like it was hitting a stopper, but a metallic rattle like something was loose. I took it apart and the noise seems to be coming from the center of the cone. You can hear the noise pretty good on the you tube vid. I don't know much about repairing subs. I'm looking for advice on if this can be fixed. If not I guess I'll have to start looking for a replacement driver for my enclosure.

 

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To me it sounds like the voice coil might be rubbing up against the magnet. If that's true there's probably little you can do with it, given the company is out of business.
 

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I've been enjoying my 21" DIY sub for 4 years now, but I've hit a problem.


The other day I was doing some rewiring in my audio rack and I think I accidentally turned up the gain on the ep4000 powering my sub. I was taking a shower with the system turned to the maximum I would normally turn it up to and when I went back into the living room there was a loud rattling sound coming from the driver. It wasn't a clunk like it was hitting a stopper, but a metallic rattle like something was loose. I took it apart and the noise seems to be coming from the center of the cone. You can hear the noise pretty good on the you tube vid. I don't know much about repairing subs. I'm looking for advice on if this can be fixed. If not I guess I'll have to start looking for a replacement driver for my enclosure.

Video Link: https://www.youtube.com/watch?v=0VPYo-T1AVo
this enclosure is beautiful. May i ask about the building process? Did you post it somewhere?

regards
 

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this enclosure is beautiful. May i ask about the building process? Did you post it somewhere?

regards
It's in his signature.

That is a disheartening sound...

What would even be a suitable replacement driver? For such an awesome enclosure, it not only would have to perform well, it would have to look just as high class. The bar is set pretty high with that enclosure!
 

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Could be VC if you bottomed the driver. Which being metallic in sound MAY be the cause. I hope its something else. The Mach 5 FTW woofer would be a great fit for the enclosure. BUT I do hope this can be fixed. One of the last Mal 21's I know of.
 

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Discussion Starter #8
The Mach 5 FTW woofer would be a great fit for the enclosure.
Thanks for that info. At least I know there is an alternative available if this Mal can't be fixed.

I was thinking I might have to replace my DIY with a JL Fathom f212 or Paradigm Sub 1. Not only is the expense of those subs uninviting, but the thought of losing my enclosure as well.
 

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You could make a ring adapter for a SI 18 if there's no saving the 21 so you don't lose the enclosure.
 

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I have two Mael 21's. I did a sonobuild that lasted all of two months before I destroyed the tubes to try to sell my house. The drivers are sitting in storage. I planned on building two sealed boxes someday. Not exactly motivated, but if the money was right I may sell.
 

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FTW with enough power will excel much better down low compared to the Fathom. They have always done very well at the ULF's. If your going to spend money like the Fathoms then just build another enclosure similar to what you have and get a SI 24". :D

I still hope this can be fixed.
 

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I remember reading your build thread a few years ago and being amazed at your enclosure! I'm really sorry for your lost and I hope you can fix it or at least find a decent subwoofer as replacement.

Was this a subwoofer you had won in a giveaway? I can't remember.
 

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Uh oh, that is very bad luck for what was a beautiful build. I've been envious of your work since I first laid eyes on it. Excellent work and results.

Unfortunately, I've heard that sound before:


It would seem that you've a shorting ring that the glue's baked loose on or something along those lines. New soft parts won't fix it. You'll need to find someone willing to try their hand at repairing the motor itself and reglue what's loose (if possible).

Shoot an email to Fi Audio and see if they've any input. They're one of the last outfits out there that can do voice coils for XBL^2 motors and the 21" cones for a 3" voice coil an be sourced. Question is if they can repair the motor too, are willing to do so (difficulty or other business related reasons) and the whole endeavor is cost effective to you.

If that proves to not be the case, you could opt for a Mach5 FTW-21, which would be a drop in replacement. The driver seems to be well-received (despite the strange rant on steel considering essentially all North American steel is mostly composed of recycled material :coocoo:) and will give you more boom for the watts though at a loss of sound quality compared to what you've been used to with the Maelstrom-X.

What is the radius of the baffle's curve, if I might ask? Does it match the original 21" or did you scale up? If it's large enough to enlarge the hole and fit a Stereo Integrity HS-24 in there, you should really go for it. That driver in that cabinet would be a thing of beauty.
 

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I have never read how a mal-x has better sound quality than a ftw- 21. Any links?

The ftw-21 works well in 7 cf with 2000+ watts if the mal-x can't be fixed.

The si 24 will be very constrained in 7cf. It likes 12+ in sealed as I understand it. A ftw-21 would work better.

Your cab is awesome! Love the build!
 

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Discussion Starter #17
With the price point of the FTW and the fact its made only 5 hours away from me has me really leaning that way, instead of fixing the Mal-21. The comment about it not having as good as sound quality made me wonder though, so I would be interested in more info if someone has it.

The 24 wouldn't fit in this cabinet, even if the cubic feet was appropriate. The diameter of that driver is bigger than the enclosure itself.
 

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I will echo the FTW21 as a replacement. I have heard only good things about it, but there are not too many out there. I will most likely use the UXL18 for my next build if I can't source more LMS-Ultras, so I feel pretty good about the company's products.
 

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Wow, I remember seeing the thread for this build and it was beautiful. Sorry to see it like this man, I can vouch for for Erasmus' assessment of the situation - it does indeed sound like a shorting ring has come loose from within the motor.

Are you able to get the dust cap off at all gently without ripping the cone material? If so, you could see if the shorting ring is one around the pole piece, and just pull it out, or try and re glue it. Pulling it out would mean you'd increase the inductance slightly, and distortion (again, slightly). However, that IMO is better than rattle.
 

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I have not heard of anyone complaining about the SQ of the FTW. Not sure where that info came from. BUT I am sure there is someone out there that doesnt like it. That being said having an amp that is fully capable of delivering enough power is crucial. While you can feed it 800watts and be happy I was not. Even with EQ they sounded great but I needed more power.

I am not saying you have o have a LOT more power, its just what worked for me. I had about 1100watts going to mine and when I finally upgrade to a much bigger I liked the change. Enough so that I didnt want to go back to a smaller amount again. I had about 4000watts going to each of them.

So capable amp and levels adjusted I would say its pretty hard to beat the 21" in any other 21" size. I do believe the Mal 21" was more sensitive down low but thats about it. They are very similar and should have similar sound characteristics.
 
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