Fi Q 12" making a strange vibrating sound...

[CaptNKILL 0]

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.

Edited June 10, 2008 by CaptNKILL

[cougarballa2k5 0]

I'd bet money you have an airleak. Ensure the woofer is mounted with gasket material as well as all screws are properly fastened. Also if possible take the woofer out and try to as I put it "finger" the seams with loctite.

[CaptNKILL 0]

I'd bet money you have an airleak. Ensure the woofer is mounted with gasket material as well as all screws are properly fastened. Also if possible take the woofer out and try to as I put it "finger" the seams with loctite.

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.

[lee 2]

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.

If I had to guess the problem your box would be it. are you shure the q logic box is 3/4 because most all that i've seen were 5/8'' wood thickness. back in 97 I had those with RF DVC 15s in em and i could here the wood smacking together under high levels. I thought the box was going to blow apart and mine were 5/8'' 1.5^3ft q logic boxes

[CaptNKILL 0]

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.

[lee 2]

OK ,well i've been wrong before. Next step is to take the sub out of the box and check it to see anything out of the ordinary.

[KU40 173]

OK ,well i've been wrong before. Next step is to take the sub out of the box and check it to see anything out of the ordinary.

That's what I was going to say. If it doesn't make the noise outside the box, it's an airleak. If carpeting goes underneath the sub when mounted there is often not an airtight seal there. Plus I doubt those people used sealant on the inside edges of the box. Also check the wire terminals on the box. If it does, something is probably wrong with the sub. The voice coil may be a little out of alignment or a little mangled in some way to make it hit the motor.

[CaptNKILL 0]

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?

Edited June 10, 2008 by CaptNKILL

[crazyder 0]

Have you checked to see if the sub is vibrating when there is no music? By that I mean turn everything on and just feel the cone, maybe the sub is motorboating from something wrong with the amp.

[NDMstang65 403]

If it falls under the warranty clause then we'll repair it...

Post some pictures of it and let me see what your looking at.

Thanks!

-Nick

[BKOLFO4 29]

Where are you located? Maybe there is someone on the forum near you that can help you figure out what is wrong.

Brian

[mrbobian 0]

How about your bass boost? When I first got my sub and amp, I didn't know any better and turned up the bass boost. This clipped the piss out of the signal. It didn't sound like distortion at all, just a vibration that was louder on the higher frequencies. Something to check.

[CaptNKILL 0]

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.

Edited June 11, 2008 by CaptNKILL