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Discussion Starter · #1 ·
Hey guys,


I just installed my diyma ref 12 in a 0.5cf enclosure. it's mounted inverted facing downward into the box (helps me save trunk space as I built a box that is relatively shallow). I'm powering the sub with an elemental designs nine.2 (400Wx1 @ 4ohms bridged). I've been warming the sub up for about a week now and decided to increase the volume up a bit today. However, when I did, I heard this funny sound. It sounds as if your holding large piece of sheet metal and bending it, then popping it so that the bend extends the opposite direction. that boing sound occurs with base notes. I opened the trunk and more of the same, and I believed the VC was bottoming out. Needless to say, I turned the volume down immediately. I'm pretty sure I'm having problems with overexcursion, and I'm wondering if anyone else has had this issue with the diyma ref 12. I'm only running 400W and the gains are set pretty low (1/2 or so). It really doesn't sound like clipping. LPF was set at 125 and 80Hz with no difference. Any suggestions?

thanks!
 

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sounds like the dreaded cone warp from internal box pressure. with an enclosure that small you should REALLY be using a ssf or highpass. I hope your woofer is still ok.
 

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Yeah, the woofer is jacked if it's making noise.

I suspect it's voice coil noise you are hearing, at least I'm pretty sure that's what it was when mine started making noise. I suspect that once the cone gets warped, the coil no longer sits centered in the gap. I'm guessing here, but it's similar to when you push a driver down on one side instead of in the middle.

I bet if you remove the driver, you'll see cone damage.
 

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The sub still sounds great at normal volumes.
Trust me, I've used these subs, the cone is buckled. It's certainly not clipping that's making that noise.

Take it out of the enclosure since it's face down, and you'll see that it is. The noise will never go away once it starts...unless you are content with playing it at moderate volume only from here on out.:)
 

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Discussion Starter · #8 ·
well, I pulled it. Cone looks mint. Assuming it's still ok, am I right to assume that damage can be avoided using a ssf/hpf? Or have people had issues with this despite limiting the frequency range the sub gets?
 

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Man that's a tiny enclosure, I'm surprised it didn't implode on itself!
Well, they were designed to run in real small sealed enclosures.

It's not the OP being an idiot with his enclosure size. In fact, Npdang says he's ran them in .25ft3.:eek:

Apparently you just have to watch the volume control, but I noticed no warning signs myself, so I have no idea what it's limit actually is before the damage.
 

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well, I pulled it. Cone looks mint. Assuming it's still ok, am I right to assume that damage can be avoided using a ssf/hpf? Or have people had issues with this despite limiting the frequency range the sub gets?

It may look ok at a glance, but I bet it isn't.

I hope it is, but I just just don't think so.

I never used a SSF, but I never could understand why one would be needed anyway in a small sealed enclosure.
 

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The box isn't terribly small since he has it inverted. Wasn't someone running one in the corner of their trunk in an Audi A4 that was like that?
 

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Discussion Starter · #13 ·
89 is correct... it actually is warped. a hairline deformity. only notice it when the light hit it just right. so, anyone care to advise my retarded self on how to avoid this?
 

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I also found the limits of my diyma 12. It is in a .85 cuft box on 400 watts and I was playing get back by ludacris and it sounded great up front so I popped the trunk and could hear a popping sound. The cone was probably moving an inch and a half. Turned it off and checked it out no damage to the cone. Don't listen to a lot of bass heavy music anyway but now I now what the limit of this sub is.
 

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89 is correct... it actually is warped. a hairline deformity. only notice it when the light hit it just right. so, anyone care to advise my retarded self on how to avoid this?
This will not be a popular idea here with some, but my advice is to run a different sub.

If you did this once, you'll do it again. Buy a sub that actually suits your listening style. The Diyma apparently isn't it.

Don't feel bad, I did the same thing and I thought I wouldn't.
 

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Discussion Starter · #18 ·
well, I loved the sub for the whole week I had it. I'm just not sure it's worth the risk trying another, even if I use a ssf.
 

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You can still reach maximum power with the gains at 0... it really depends on the output of your source.

As 89Grand suggests the DIYMA is not a product for everyone, especially if you're looking for your sub to be heard. If it's just a hairline bend in the cone it should have absolutely no effect on the sound at regular listening volumes. The popping your hearing isn't the voice coil bottoming, but probably the cone coming close to warping.
 

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Just gotta say the DIYMA Ref is a top tier sub in the sq line, its not a loud one, but configured right and with an ear and its capabilities in mind, it can do phenominal things, mine is still running strong with almost 3 yrs of play on a single 500rms, 1cf. ssf @ 20hz. I do drive a hatchback so some low end gain is added, so huge spl levels arn't needed, but it does thump nicely, and digs deep.

I'd keep using it......As for how to avoid pushing it any farther, don't push the sub past its limits, you know them now! Take a picture and post how bad it is.
 
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