[Vr3]

Why would I be bottoming this sub?

My room is 10.5x10.5x8 ---

Amp is 1400 watts, 4 ohms (Crown XTi1000 bridged)

And in low frequency passages... it bottoms at not even reference levels for my small room...

I unbridged the amp to 500 watts, 4 ohms ----- and turned the limiter on. Havnt retested.

Any thoughts?

PS: Sounds like the PR is what hits bottom.

[Brian Cheney]

We can fix that if you return the PR to the factory.  Send to Itone Service, 2031 Rumrill Blvd #6 San Pablo CA 94806.

How old is the Larger?

[Vr3]

Its probally 2 months old.

Why would the PR be bottoming?

[covermye]

I've got the same problem, and have spent a maddening amount of time trying to find an air leak that I don't think exists.  Brian:  What do you do to the PR to keep this from happening?

Same thing for me, the "bottoming out" noise comes from the PR for sure.  I've re-sealed all drivers and hot glued every joint inside the box to try to prevent any air leakage, to no avail.  Only happens during very low frequency passages.

[Vr3]

Yeah.. I'm just curious what is done to the PR to prevent this and why isnt it done from the factory day 1?

Because there is no reason in my small room this sub should be close to bottoming out...

Thanks

[Dan Nelsen]

My Larger with megawoofers, made 10/2002, is now making the flapping sound described in this thread and also these threads:

2004
2006

Nobody ever followed up to say if they fixed it or still have the problem.

I've removed and vitrified the PR, checked for loose parts, cushioned the wires with fiberglass, and carefully sealed the PR.  Still flaps on any type of LFE pulse (gunshot, explosion, etc.), and not at extreme levels either (-15dB below reference).  I haven't tried re-sealing the drivers yet.

It didn't flap when new, but now does after sitting unused for 2 years.  So is it an air leak, worn out PR or driver, etc.?

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[Vr3]

Ive since sold my Largers

Brian sent me a PR that he said was not possible to bottom. It didn't bottom again.

But I found the biggest problem was the fact my DVD player was hooked up with RCA cables...

Hooking it up with Optical fixed this problem, but I dont have a surround system so it introduced other problems but it definitely fixed the Largers bottoming problem. The room was falling apart after that...

[Dan Nelsen]

Brian sent me a PR that he said was not possible to bottom. It didn't bottom again.

But I found the biggest problem was the fact my DVD player was hooked up with RCA cables...

Thanks.  I'm waiting to hear from Brian for the cost of a new PR.

Analog vs digital LFE difference sounds like a setup issue, since normally a source reduces analog LFE out -10dB and a prepro boosts its analog LFE input by +10dB, or something like that.  Mine is digital.

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[BC Dave]

I ordered a 12 inch Megawoofer and a new passive radiator a couple of years ago for my VMPS Original subwoofer and have since noticed severe distortion with fdemanding ilm clips such as the lightning scene in War of the Worlds, even at moderate volumes. However the sub sounds fantastic with deep bass in music. Brian, could I use my old passive radiator with the newer megawoofer? It's a hassle to ship the newer passive radiator back to you from Canada and pay brokerage fees etc. By the way, WHY is this passive radiator malfunctioning? I take it that the fault lies strictly with the PR because the Megawoofer is designed so that it can't bottom out?

[Dan Nelsen]

I just received and installed the new PR, and the flapping sound is gone.  It sounds as good as new!

There's quite a difference between the new PR on the left, and the old one on the right:


Comparing the two, I see that it doesn't take much movement for the old PR cone to hit the frame at the point where the cone is attached to the foam surround.  I think the new PR frame eliminates that.

Also, the new PR has a much wider blob of hotmelt (or silicone?) on the spider which makes it stiffer and reduces  the maximum movement.

I can now see that my old PR had almost no tension left.  Before, anything below 20Hz sounded like a motorboat "putt putt putt".  Now 16-18Hz tones sound like tones.

Thanks Brian!

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