Shredding Soft Parts

[DJ Nitrous 427 10+ year member]

Howdy. A buddy of mine has a pair of MT 12s on a Stetsom 7kw (part of matrxx dude's old setup). Matrxx Dude built his box for him I'm not sure of it's the volume, hopefully he will chine in. Anyway...

they've been reconed with RE kits...ripped the dustcap off and screwed up the cone...

they've been reconed with IA kits...ripped the surround where it meets the baskets

they've been reconed with FI kits with supposedly 7 spiders...ripped the dust caps off again and messed up the cones

wtf is going on?

Click to read more...

 

[silvercookie 5,000+ posts]

stetsom pwns joo

 

[audioarsonal 10+ year member]

What freq?Maybe its below tuning and your unloading the subs causing the failure?

 

[jmanpc 5,000+ posts]

MTs have a tendency to mangle soft parts.

 

[NDMstang65 10+ year member]

Your not putting the dustcaps on right...

15 minute 3700psi epoxy, 10lb weight until it cures and then put the incredible goop on top of them...unless you know how to properly apply them with the black CA glue then they'll never hold on with that either.

MT's are going to be bad about blowing the dustcaps off due to the solid square pole that is in them, it builds up too much pressure...especially if they aren't put on right. Make sure the dustcaps are sanded with 40 grit as well.

Edit: Big thing could be a pressure spot in the box, or that amp is throwing the cone around all over the place and causing it to 'ripple' slinging the dustcap off..

 

[DJ Nitrous 427 10+ year member]

The paper cone is separating...the glue is not coming off...its ripping the cone.

We're blowing the dustcap off and it's ripping the top layer of the cone off where the cap is glued on.

 

[NDMstang65 10+ year member]

Mess with the box and get rid of the pressure spot that's in it...

It wouldn't happen to be in one of those tubes with a 6" aero out the back like a street car would it?

 

[DJ Nitrous 427 10+ year member]

No..its a standard rectangular box with 4" aeros. I saw matrxx dude looking at this thread about an hour ago but he didn't say anthing.

 

[matrxx dude 5,000+ posts]

pressure spot,hmm.so ur saying to much backpressure,its in a wood box,4.5 cubes with 2 4'' aeros,in a toyota avalon trunk car facing forward sealed off from the trunk.

 

[DJ Nitrous 427 10+ year member]

Video

 

[NDMstang65 10+ year member]

pressure spot,hmm.so ur saying to much backpressure,its in a wood box,4.5 cubes with 2 4'' aeros,in a toyota avalon trunk car facing forward sealed off from the trunk.

Wait, you've got a single 12 in that big of a box?

2.5 cubes is about as big as you need/want to go...even smaller with that much power.

 

[DJ Nitrous 427 10+ year member]

2 12s the pictures are of 1 sub and the video is of the other

as you can see in the video, the glue is holding...the cone is not

Matrxx Dude ordered the kits from Scott himself, and he said that Scott told him the subs should be able to take 3k daily ea....

 

[NDMstang65 10+ year member]

No clue man..never seen that before in all honesty. Out of sheer curiousity, take a razor blade and cut around the edge of the dustcap and put some epoxy back on the cone and reapply it and see if t hey do it again..

Something really weird is going on for parts to be shredding like that..it simply doesn't happen. Looks like it's just building pressure underneath the dustcap because the MT does not have a pole chamfer to keep it from building pressure...nothing you can really do about it either...

Cut it with a razor blade and glue it back down, go to autozone and get a tube of the 'incredible goop' and goop the edges of the dustcap to the cones...we used to do it with Scottie's subs all the time...only way the dustcap would stay on..

 

[tommyk90 5,000+ posts]

2 4" aeros isn't enough port area for 2 12's, especially MT's with a decent amount of power.

Step it up to 4 4" aero's or 2 6" aeros minimum. What's likely occuring is a LOT of pressure on the backside of the cone because of insufficient port area. Combine that with the solid pole piece and you have instant destruction.

 

[bass-aholic 10+ year member]

2 4" aeros isn't enough port area for 2 12's, especially MT's with a decent amount of power.
Step it up to 4 4" aero's or 2 6" aeros minimum. What's likely occuring is a LOT of pressure on the backside of the cone because of insufficient port area. Combine that with the solid pole piece and you have instant destruction.

im glad some one pointed that out, at first i thought it was 2 4" for 1 sub but than i realized it was for 2 subs. That could definitely be the problem.