CaptNKILL

I'm in north western Pennsylvania, I doubt anyone here is from my area of the "woods". heh And I don't use any bass boost so I know it isn't that. I really don't think its related to clipping since it does it at moderate volumes. Hopefully I'll be able to get some caulk at the store today and reseal my box. I'll check out the sub then too. Is there anything on the sub that I should check for that could be loose or misaligned? BTW, what do you guys think of adding polyfill to a sealed box? I've got a bag of it laying around and I was thinking of adding a bit to my box to see how it sounds.

If it turns out that it is the sub, will Fi repair it under warranty? And will I have to ship it to them at my own expense?

This is the box I'm using. http://www.crutchfield.com/App/Product/Ite...S125&tp=127 It says 3/4" MDF, but I haven't measured it myself. I don't know if it'd be the wood itself. I have plenty of songs that hit much lower and louder than the ones that make the sub vibrate. It just happens at certain frequencies. The noise really sounds like its coming from the sub itself too, not the box.

Just to clarify, what did you mean by "mounted with gasket material"? And which seams should a touch up? Just everything visible on the outside of the cone? And would plain old super glue work? Also, I edited my original post. Made some stupid errors. Fi Q doesn't have a copper coil option... I was thinking of the SSD I was originally going to buy. And I'm using dual 1 ohm in series for 2ohm load.

I've had my Fi Q 12" (no BP option) for about a month and a half now and its been making a strange vibrating noise at certain frequencies since I bought it. I thought maybe it'd just need broken in a bit since seems to be hitting really well and doesn't sound distorted. But its still making the noise as much as it was the first day and its been broken in plenty since then. I made sure that it wasn't anything in my car rattling. I used an extra long run of speaker wire and put the box outside of the car and it was clearly the sub itself that was vibrating. Its audible with certain sounds in certain songs at a moderate volume but actually gets pretty irritating at high volumes. Its a bit hard to describe but it just sounds like two pieces of plastic or painted metal vibrating with the movement of the cone. Here is my setup: Kenwood KDC-X491 head unit Fi Q 12" dual 1 ohm Q-Logic 1.25cu sealed box made from 3/4 mdf Kicker ZX750.1 rated at 891W, wired to 2ohm Kicker ZX200.2 running Eclipse SC6500 components in front doors (rears are faded out) Using 4 gauge amp wire and 12 gauge speaker wire for the sub I've also done the Big 3 upgrade using Knu KLM 1/0 gauge in my 2006 Hyundai Sonata V6 with a 130amp alternator and factory battery. I have no problems with dimming and at high volumes my DMM measured around 13.8v at my sub's amp, so I'm not having any power issues either. I've also set my gains with a DMM so I'm pretty sure that the amp is not clipping when this happens. I'm thinking of trying to reseal my box since it is a pre-made box and it probably isn't perfect, but I doubt this is the source of my vibration problems. Does anyone have any ideas as to what this could be? I've done a lot of research for this system but this is only my second system build so I'm clueless when it comes to troubleshooting problems like this.