ugh- sub bottoming

[jdawg90 10+ year member]

Okay so I blew one of my sa-8's when I had them in a trunk car. I just reconed the blown one and put it back in the same box, only this time it is behind my seat in a truck. The reconed sub will bottom out on music that the other sub doesn't bottom out on. When I rest my hand over it this stops the bottoming. I also notice a slight rubbing/rattling sound on some notes. Not a blown sub rattle sound but it is there nonetheless. Any idea why one sub will bottom while the other one doesn't? The only thing I can think of is it has something to do with the four small holes drilled that I used to run my 10 gauge speaker wire through when it was in my old car. There are no air leaks around the sub gasket.

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[dbeez 5,000+ posts]

You mean the sub is unloading? I bet its a loading issue on the box design side post up some pics of box and specs.

 

[garychoffmann 10+ year member]

Did you do a drop in recone or did you assemble it? Did you happen to notice the coil winding depth into the motor?

 

[jdawg90 10+ year member]

You mean the sub is unloading? I bet its a loading issue on the box design side post up some pics of box and specs.

This happens at frequencies above tuning on some songs. I built the box several years ago, i don't have the specs, its somewhere around 1.4 cubes at 33hz if I remember right. What exactly is a loading issue?

Did you do a drop in recone or did you assemble it? Did you happen to notice the coil winding depth into the motor?

It was a drop in. Idk what you mean by that^^

I suppose I should build a new box and go from there.

 

[garychoffmann 10+ year member]

I've seen people recone a sub and put the voicecoil too debep into the motor. But if it was an assembled drop in I doubt that would be the case.

 

[dbeez 5,000+ posts]

Unloading or loading issue I am referring to is the one sub basically has no cone control from the box due to many different reasons if no air leaks and they would have to be significant then I would say the sub that's unloading is doing so csuse its more than likely firing directly into the port opening on the inside of the box and probably the reason you hsd to recone it in the first place.

 

[basswiigee]

last time my sub was doing that i ignored, and my spider seperated!!! check the spider good... may have a small tear...

 

[Full Tilt 10+ year member]

Okay, I've got a couple questions for clarification.

1. Is the sub in the same place that it was before your recone?

2. Have you tried putting another sub in the same place in the enclosure to see if that does the same thing?

3. Do you remember what happened to the other sub (how it blew)? What is blown because it was mechanically strained or was it a thermal problem?

4. Did you notice any sort of sound before you reconed it? Also, are you positive you're bottoming out, and not rubbing the coil/former somewhere in the gap?