Excessive woofer movement with a VPI JMW 9 ?

It looks like the OP solved the problem but I thought I'd post regardless as I'm a little concerned with some advice that was offered in this thread. Rumble is a quite common phenomenon associated with analog playback and can occur even when everything else in the system is well matched. Here's a quote from KAB: "This very low frequency energy is called rumble. Much of it is actually cut into the record groove when the master disc was made. The only way to suppress it is with a really good rumble filter." It can also be worsened by warps in a record, but I've experienced it even with perfectly flat records. Advice such as "You need a different cartridge," is in my opinion not only useless but may send someone on a goose chase and cause him to waste time and money to no avail.

A few days ago I spoke with Jim Pendleton from Osage Audio who is always a great resource for anything analog related and carries the KAB filter in his online store. I also experience rumble with my Scout and JMW-9T and Totem Hawk speakers, usually not bad, but once in a while to the point that I'm afraid the voice coils might get damaged. (Interestingly, the worst woofer pumping occurs with a copy of Black Sabbath "Paranoid," which is an otherwise perfect and great sounding pressing.) Jim said that he has used the filter, and in his listening experience the KAB filter does not negatively impact the sound. His opinion seems to confirm others' experience with the filter, which is good to know and puts me at greater ease as the package from Osage Audio is waiting for me at home as we speak...

Ported speakers or ported sub + vinyl = subsonic filter. It doesn't matter how well the cartridge is matched to the tonearm or how well the table is isolated. You will benefit from a decent subsonic filter.

Thanks guys. I had a local guy (Morgan Sound, seattle...really great techs by the way...) build a 20 and below filter for my sub, which is where i had the problem.
It worked great. Thanks again. sm2727

KAB rumble filter worked for me too. HW-19, Audioquest arm and Sumiko Blackbird, Wright pre/phone.

I've owned both the KAB and DB Systems units in the past - both effective without any negative sonic impact to my ears.

Anyone tried the DB Systems Subsonic Filter?

-Bob

Another vote for the KAB rumble filter - I went through so many scenarios ad naseum before buying one - cartridge compliance, phono stage gain, isolation feet, mounting the table to the wall...on and on.

The KAB is a miracle worker, plain and simple.

You need a different cartridge..

Yep rumble filter needed....Had a phono amp, cheap variety no rumble filter, bought a little better one with rumble filter, woofers dead solid, dead silent. There is not much below 20hz on a vinyl pressing accept surface noise, so you won't lose anything in the musical sense, just background noise.

Now if you did not have this issue before this arm all together and another one you used originally did not exhibit "this issue" on "this same system" in question than yes it is coming more from the new cart/arm combo, however still can be eliminated using a phono stage with a rumble filter or adding the after market version stated above. Either way you need to block that noise, so starting over with a perfect cart/ arm combo may not be easy, and unnecessary until you try a rumble filter.
Good luck

amp and preamp is?

I hesitantly tried the KAB Rumble filter to address the same problem you're having - excessively pumping woofers. I'm glad to report it really did the trick, and with no sonic compromises I can detect. An added, unexpected bonus: my table seems much less susceptible to footfalls with the rumble filter in place than it was without.
Got mine here on A'Gon for around $160 - they turn up every now and then, and you could probably turn it around at no loss if you try it and don't like it.

The problem is not endemic to unipivot arms. The problem is probably an arm/cartridge resonance that is either too low in frequency or too high in amplitude-- or both.

most likely you have the cartridge that is mismatch with the JMW9.
what cartridge are you using?