[audioguy213]

So, if I use a TT with my system, even at silent passages between songs, I can see my woofers jumping around like MAD, tons of xMAX, with no actual bass sound associated with it.

This is with any TT, any phono pre (both tube and solid state) , with any integrated or separates.

The sound is fine, the vinyl sounds great, but I am literally worried about the safety of my drivers watching them oscillate like that -
I flip to the same track via DAC and the sound output is comparable but the woofers are moving MUCH less,

Is all vinyl sending some sort of low inaudible rumble that none of my gear has the RIAA to filter out?

[Phil_S]

2 things are happening, there appears to be feedback between the turntable/cartridge and the speakers, and there's very low frequency information being transmitted to the speakers.

The primary cure is a low frequency filter.  This should take care of the speaker pumping you are witnessing.  The second issue is one of isolation.  The turntable needs to be sonically isolated so it doesn't pick up the vibrations from the speakers (feedback).  There are many threads here and on other forums addressing both issues.  Do some research. The cures need not be expensive.

[lcrim]

Hi:
You are experiencing rumble.   Check out http://www.kabusa.com/ for the KAB RF-1 rumble filter.
    Getting into LP's and startled at the big speaker cone movements that you're seeing? Thinking a better turntable will help? It may not! This very low frequency energy is called rumble. Much of it is actually cut into the record groove when the master disc was made. But the main source is feedback exciting the natural stylus/arm resonance between 7 and 12 hz. This produces a slow easily visible in and out motion of your woofers. If you cannot see this motion, the RF-1 will not solve your feedback problem. If you can see this motion, the RF-1 will solve your feedback problem.


  Larry

[Ericus Rex]

Compliance issues; your arm and your cartridge are mismatched.

[Wayner]

First off, the OP didn't tell us what table or cartridge he has, so saying that there is a mismatch doesn't cut it right now.

I'd first ask where the table is in relation to where the speakers are and what is the table sitting on....

[hibuckhobby]

I'm with Wayner.  Isolating Tt both acoustically and the electrically ( if need be)
will lkiely help a great deal.  Also issue of record warpage?
Hibuck...

[audioguy213]

it's because none of my gear has a subsonic filter in it, a rumble filter should resolve as someone mentioned earlier. I am working on that.

the TT is isolated, it is on herbie's feet, it is on the other side of the room, and it is isolated from the floor or floor vibrations.
The table is on a poured concrete mantle, on a separate wall from where the speakers are,


The cart is a Kiseki Purpleheart NS, it was properly set up, it is on a Jelco tonearm on a Merrill Polytable,
the vinyl is new 180g pressings, but sometimes they are not perfectly flat  at the rim (I use a weight, but no edge clamp).


Chinook Phono pre, then Nuprime separates, but previously Hegel integrated,

I have a cheap Thorens with Schiit SS phono pre that I tested - same issue.

Uberbuss, TWL power cords, dont worry about electrical isolation or issues.

the problem is persistent, regardless of components, I did the usually troubleshooting changing one thing at a time throughout the chain, etc.

Thanks to all for their feedback ,I will report back once rumble filter installed.

[Wayner]

I don't have any woofer pump at all. A filter is a band-aid to another, underlying problem.....

[*Scotty*]

This may sound crazy, but does the woofer pumping change in any way when the table is used sans the Herbies feet?
Scotty

[Pete Schumacher]

vinyl rumble is usually an out of phase condition, hence not hearing anything from the woofers even though they are moving like crazy.  Back in the day, I built a low frequency summing circuit that basically caused the left and right out-of-phase low frequency information to cancel out.  An infrasonic filter can work, but that circuit I built worked even better.

[neobop]

You'll usually see pumping in vented speakers when they're fed subsonic info below their resonant frequency.  The woofer cone pumps, but no sound comes out while trying to play this out of band signal. 

This may sound crazy, but does the woofer pumping change in any way when the table is used sans the Herbies feet?
Scotty

Possibly.  The vast majority of woofer pumping is caused by acoustic and/or mechanical feedback.  If you do a search here or other vinyl forums you'll see the solution is usually mechanical.  Having a table on an unstable platform or rack is the number 1 culprit.  If you couple this with wooden floors which act like springs, you're asking for problems. 

A subsonic filter treats the symptom, but the root cause is still there.  High amplitude subsonics cause distortion within the audio band, so it's better  to treat the root cause.
neo

[BobM]

You could have a mismatch between your cartridge and tonearm. This is not uncommon - it happened to me and I had the exact same problem as you. Here's a link to an article that explains cartridge-tonearm compliance:

http://www.gcaudio.com/resources/howtos/tonearmcartridge.html

Here's a link to a calculator that will help you determine if there could be a problem.

http://www.resfreq.com/resonancecalculator.html

[audioguy213]

thanks for all the replies,
this happens with numerous TT, numerous arms, carts, and several phono pres., tables are in different places with different isolation systems (suspension), Herbies, among others.

I think it has more to do with:
1. living in an urban environment with subsonics from heavy trains (if it is mechanical resonance)
2. ported speakers, no rumble filter anywhere, resolving gear


1 I cannot fix,
2 will resolve the issue, I suspect and I will report back in a few days.

[*Scotty*]

What loudspeakers are you using?
Scotty

[dB Cooper]

Agree 150% with BobM: Your system has a severely underdamped low frequency resonance, most likely arising from incompatibility between the tonearm and cartridge. (This past Capital Audiofest, I noticed that the woofers in the system they were giving away were flopping back and forth noticeably for the same reason). If it's in the tonearm/cart interface, it can be fixed by finding a more compatible cart (lower mass and/or compliance) for that particular arm.

If there is that much LF noise pollution in your environment, vinyl may not be practical for you.

[audioguy213]

inserting a rumble filter resolved all issues perfectly, thanks all,
system sounds perfect.



I use a Merrill table with a Jelco 10 inch arm, a Kiseki Purpleheart NS cartridge,
feeding a Manley Chinook with Amperex 7308s,
feeding a TDSS modified Nuprime Dac10 and ST 10 combo
I use  ZenWave D2 interconnects
Triode Wire Labs Digital American and digital Am HP power cords
Uberbusses with Mongos
Herbies Feet
Odyssey Audio Kismet Beryllium floorstanding speakers (rear ported, hence the woofer bounce)




When I want to troubleshoot I break out Hegel integrated, monoprice cables, and a Thorens TT that feeds a Shiit Mani phono pre - those are the things I let my my wife touch on the other side of the room that hook into my main system.

[Stercom]

It's your ground connections. Even if you think they are good double check them.