Hi Stereo5...just curious. You mention buying your table from a high-end audio dealer in Newton, MA and they did table setup. Which audio dealer are you referring to as i live in the Boston area and was not aware there was a high end dealer in Newton? In any case, what does the dealer suggest? The KAB rumble filters sound like the right fix, especially if you are not flexible in terms of wall mounting the table or changing speaker positioning. Good luck.
I am guessing it was Newton but the dealer is Goodwins High End. My bad, it's Waltham Mass. I got confused because the Newton/Wellsley exit on I 95 is close by. I really don't like the idea of inserting a rumble filter via the tape loop into my system.
You are experiencing acoustic feedback. You need to move the table to a difference location.
I agree with Sidssp. You probably had your table setup by Jim F at Goodwins. Have you asked him for his recommendation?
Actually, I hadn't thought of that. I'll give him a call in the morning.
Try a 'constrained layer' dampening.
The idea is to have the TT with an increased mass on top of a rubber, ? whatever, rubbery like layer, then another massive layer. So the rubbery layer really cannot move, it can only absorb vibrations.
i use round 3" thick concrete patio blocks (5" round) on my basically cheap TV level rack, with rubber chemical bottle stoppers, then the 2 TTs with mass added to the bases under the table. I have the TTs across the room from my Maggies 3.6 and do not have a problem, though the floor is wood.
Also, even if your rack is vertically stuff, it may not be horizontally stiff enough. See if pushing on the top of the rack sideways while the phenomenon occures lessens the woofer pumping. If it does, then your rack is moving sideways!
your preamp has a filter, it's on the front panel next to the mono botton, push it in, you don't need to buy anything, that will solve the problem
Also call Audible Illusions. Why would the low filter on your preamp function so much differently than the KAB. Find out the rolloff frequency for both.
I have had Jim set up the two tables that I purchased from Goodwin's and he does a great job. I would give he or your salesman there a call and discuss the problem, I am very confident they can resolve the issue for you. Best of luck.
oops, didn't see that you already tried that.
two things, there is a good chance that the filter is not working correctly. when I had my AI it eliminated woofer pumping. the other is a 103 is a mismatch compliance-wise with a JMW-9. people run them but the numbers are way off.
Bob, I had the same situation where I couldn't move the turntable and couldn't mount it on the wall, etc.
The KAB rumble filter finally solved my troubles a few years ago, and I've never looked back.
I would check with VPI and see what they think of the effective mass/mechanical resonance issues with regards to playing that cartridge in your arm.
The mechanical resonance should be between 7 and 12 Hz, if its off, you can get crazy woofer pumping. The way you describe it, this problem did not show up until you got the table setup done recently- that really points to the arm/cartridge compatibility issue.
So Bob...were you able to fix your "woofer pumping" issue?
The table wasn't recently set up. I have had it for 2 years. It is definitely the turntable picking up resonant energy from the turntable. I am going to try the KAB filter first and go from there.
Bob, please let us know what you think after trying the KAB.
I think you're going to be hit with large waves of relief!
the object is to shortan the distance from needle to speaker. filters just increase that distance. adding and taking away from what was intended. at best, masking the problem. at worst, killing the sound. don't wall mount! your issue is vibration, airborne or cart/arm. owned the vpi aries with simalar, if not exactly the same tt feet on it. high volume vibrated like crazy. moved up to the HRX never had the problem again. the scout is a relitively light tt(total 40lbs). making it harder to isolate. you need a heavy rack with a well insolated platform for the best isolation of the tt. maybe you can upgrade to the super scoutmaster feet or even better up the vpi chain to the super scoutmaster tt. vibration is what it is all about. controlling vibration, not trying to mask it, thats where it's at. best of luck
If you haven't already pulled the trigger, I would hold off on the KAB until you have made sure mechanical/design solutions have been exhausted.
1) A slight variation on what Elizabeth is suggesting above, I would try a very heavy wood or concrete platform (as heavy as you think your rack can handle) between your table and your rack isolated from the rack by sorbothane dots or equivalent.
2) Similar to what cpk is suggesting above, I would run the numbers on the compliance match with your cartridge and the tone arm. This could accentuate problems with rumble. Switching cartridges to one that is more compatible may solve the problem.
Turntables are mechanical devices first, and I would look to mechanical solutions before trying electronic soluitions.
Finally, this is an interesting test of the capacity of the Kidsmets to reproduce low frequencies. In some ways, a "good" kind of problem to have if solution is ultimately at hand.
Replacing the cartridge is not an option for me, but I will try some different platforms on top of my audio rack. I thought that since I had originaly had the Scout sitting on top of a 2 inch thick slab of black granite would have eliminated that possibility.
Yes, the Kismet Reference speakers are giving me the best bass response of any speaker to ever grace my living room. Actually the mids and highs are the best as well with these new speakers. As incredible as these speakers sound when played loud (100db+), they sound just as incredible at low listening levels (80-85db) At the lower volume, I never have that feeling that something is missing.
If I can just lick this turntable problem I will be in true audiophile heaven.
Installed KAB rumble filter on Friday, problem solved.
I have an AI Modulus 3 and an ARC SP11 mk II.
When using the AI with filter on there is still alot of woofer movement on my 801 matrix s3 speakers.
When using the ARC preamp with filter on there is minimal movement.
LOL, I'd say Knownothing knows quite a lot. ;-)
I'm happy you're happy but the problem is not "solved". It's papered over. You can't eliminate mechanical behaviors in a source component with a downstream electrical filter. That's nonsensical. A genuine solution requires investigating the root cause and addressing it directly.
Your cartridge is still vibrating at the same low frequency. You've attenuated the resulting signal before it reaches your amp and woofers but it's still muddying the signal path from cartridge to preamp (not to mention shortening the lifespan of your cartridge). We never hear such mud until we eliminate it, at which point we're inevitably astonished at how much more music there is. That would indeed be Audiophile Heaven.
The most likely cause of this problem is the demonstrable mismatch of a Denon 103 on a JMW 9, with ineffective TT isolation being the next most likely. Several knowledgeable posters tried to suggest this. There's more vinyl expertise here than at fifty Goodwin's and that's presumably why you asked. Why request expert guidance if you're determined to ignore it?
Your a priori refusal to investigate the real problem or consider real solutions dissuaded me from answering. I commend those who tried, but why bother? I'm only posting now to warn others who stumble across this thread and mistakenly believe you've found the optimal solution. You haven't.
I half agree with you. Stereo5's problem was caused by acoustic feedback. Putting in a rumble filter basically interrupted the feedback loop. Of course an ideal solution would be to relocate the TT but since he has placement constrain, rumble filter is a good fix.
If the problem were caused by cart/arm mismatch, oscillation should happen regardless of volume level which was not the case here. Oscillation only started when volume was above a certain level. It was acoustic feedback.
I am not in the financial position to buy a new low output mc cartridge and I spoke with Mike at VPI and he said the cartridge is NOT a mismatch for my JMW9 arm, especially since I had the new and heavier counterweight. I purchased the cartridge from Audiofeil and he has assured me that he has sold many of them to people with VPI Scouts. Since the problem happened when the volume was up after a certain level, tells me it is more acoustic feedback than anything else. Relocating the turntable or putting it on a shelf on the wall wasn't/isn't an option since I share the living room with my wife. She has been really good about my sound system, so why rock the boat?
I tried many different tt isolation tweaks: I removed the turntable off the slab of granite it was sitting on, I tried a friends Black Diamond shelf, I put tennis balls under the tt, I tried a Townshend seismic sink (borrowed from a friend), I tried my Big Rock setup (box filled with sand and floating shelf on top, and NOTHING helped. So
Dougdeacon, why do you have the audacity to say I didn't try other posters suggestions????? Stop trying to read between the lines.
The KAB rumble filter did it's job, I am happy, end of story.
Funny that this problem reared its ugly head with new speakers that just happen to be ported.
Enjoy the KAB and what it has done for you and don't worry about it. It is a very good product.
I believe it is because the combination of being a rear ported speaker and the speakers proximity to the rear wall. That is something I couldn't change. The speakers also go much lower than the DeVores and much more cleanly.