Scraping problem with VMPS Larger subwoofer

IanS · « **on:** 25 Sep 2004, 04:29 am »

I bought a used VMPS Larger subwoofer with a megawoofer and carbon passive radiator, and its in very good shape, but it has a problem with the active megawoofer scraping and vibrating against the pole piece. I think this might have happened during shipping, but I'm not sure. If I push back and forth on the passive radiator, the scaping sound is quite clear.

Is this something I can easily fix myself by bending the area around the pole piece(or something else?) or does it need to be send back to Brian for refurb?

Also, is there a megawoofer option for the smaller of the two active woofers? If so, is it worth upgrading that one if I have to send the larger megawoofer back?

Thanks, Ian

sbcgroup1 · « **Reply #1 on:** 28 Sep 2004, 06:47 pm »

You should probably just flip over the sub and remove the passive radiator and then check out what's happening.

-Ed

IanS · « **Reply #2 on:** 28 Sep 2004, 07:06 pm »

Is it better to remove the passive radiator than the woofer itself, or just easier due to the lack of wiring?

When I mentioned pushing on the passive radiator before, I was just doing that to create even pressure, to ensure the scraping wasn't just the way I was pushing the woofer.

-Ian

sbcgroup1 · « **Reply #3 on:** 28 Sep 2004, 07:12 pm »

Both are easy to remove. A woofer is just a speaker cone with two wires attached to the rear of it.

You said the noise was coming from the passive radiator. In that case, remove that one and check it out. After you take it out, hold the cone up by the edges and gently flex the woofer in and out. If it's making noise, find out where. You might as well do the carpenter's glue tweak while you're at it. It will also make it stiffer (good).

Also, it may be as simple as a loose screw....

-Ed

IanS · « **Reply #4 on:** 28 Sep 2004, 07:43 pm »

I unscrewed both the large woofer and PR, and neither wants to come out. They're really wedged in there. I even popped that wooden plug off trying to get the woofer out. It looks like the woofer cone and the countersunk hole are extremely tight, which is whats keeping it in.

I'm up for suggestion on ways to get it out.

The sound actually appears to be coming from the voice coil rubbing on something on the inside of the larger woofer. Hopefully with the woofer out it'll become obvious whats wrong. It could be as simple as some stuffing getting caught in the gap.

-Ian

John Casler · « **Reply #5 on:** 28 Sep 2004, 07:53 pm »

Quote from: IanS

I unscrewed both the large woofer and PR, and neither wants to come out. They're really wedged in there. I even popped that wooden plug off trying to get the woofer out. It looks like the woofer cone and the countersunk hole are extremely tight, which is whats keeping it in.

I'm up for suggestion on ways to get it out.

The sound actually appears to be coming from the voice coil rubbing on something on the inside of the larger woofer. Hopefully with the woofer out it'll become obvious whats wrong. It could be as simple as some stuffing getting caught in the gap.

-Ian

Hi Ian,

When I first read this I thought it was probably the VC scraping and not the pole piece rubbing on anything.

Contact your dealer or Brian for instructions, since the woofer will likely need to be replaced.

The woofs are generally placed on a sealing gasket that is sticky. Usually removing the screws and placing the woofer/speaker face down will allow the adhesive to gently let go (place a pillow under the woofer so it doesn't fall out and break the wires)

It that doesn't work you might have to remove the PR and gently "push" it out from the inside.

Good luck

IanS · « **Reply #6 on:** 28 Sep 2004, 08:31 pm »

Since I'm in Pasadena, I think you're my local dealer

I'll try to let it fall out on its own then and give you an update when it does.

Thanks, Ian

John Casler · « **Reply #7 on:** 28 Sep 2004, 08:46 pm »

Quote from: IanS

I bought a used VMPS Larger subwoofer with a megawoofer and carbon passive radiator, and its in very good shape, but it has a problem with the active megawoofer scraping and vibrating against the pole piece. I think this might have happened during shipping, but I'm not sure. If I push back and forth on the passive radiator, the scaping sound is quite clear.

Also, is there a megawoofer option for the smaller of the two active woofers? If so, is it worth upgrading that one if I have to send the larger megawoofer back?

Quote

Since I'm in Pasadena, I think you're my local dealer

I'll try to let it fall out on its own then and give you an update when it does.

Hi Ian,

I missed that this was a "previously owned" woof.

So to answer your questions:

It would seem strange for you to have one "Mega" and one "stock" Woofer in the unit. I have only had one ordered like that, so it does happen.

Since one is failing, it would be best to "upgrade to both Megas ($140 for both with returned woofs, $70 for one)

E-mail or call me if you have any questions and let me know when (or if) the Woofer drops out. (it may take some gentle prying, but be careful not to damage your cabinet

)

IanS · « **Reply #8 on:** 28 Sep 2004, 08:54 pm »

Thanks for the information about the megawoofers. It seemed odd to me as well. The person I bought it from told me his friend told him what to order, so maybe he was confused when he ordered it.

Please email me at: iswett at yahoo dot com about when I could come by to exchange my existing woofers for two megawoofers. I don't know if you typically have extra in stock or not?

Thanks, Ian