Why are my woofers pumping?

@o_holter I must echo armasphere.  Pumping once per revolution is not electronics.  It has to be bearing or platter related.   It acts like a warped record.  Have you checked to make sure your platter is dead level?  Put a small bubble level on the platter and turn it slowly by hand to see if it is level through a complete rotation. Repeat this with the level in different places on the platter.  Don't use one of the small round levels supposedly designed for turntables.  Use a fairly short (6 to 8 inch) carpenters level.  Second, have you checked to make sure the platter is not wobbling on the shaft?  Good luck.

@o_holter This really sounds like a turntable problem to me! I've dealt with this a lot; I repaired consumer electronics for a living right out of high school, through college and beyond. If its once per rotation, its something to do with the platter and literally can't be anything else.
To prove this out, change the speed to 45 rpm and you should see the pumping speed increase with it.

Channel imbalance in woofer pumping? No. Mystery resolved. It turns out that one of the driver tubes in the left channel amp was going bad - at first, just weaker sound (and less pumping), but after plugging in the ASR and going back and forth to the Io, the sound became clearly distorted. Failure of a brown-base 67SN7GT Made in China. Replaced with a Electric Harmonix tube. Now the channels are equal in volume, and in pumping.

I am back to square one. Invictus005 was right: "There’s nothing you can do. It's normal. .. Just live with it and when the stylus wears out get something else." 

I disconnected the Aesthetix Io, and connected the ASR mini basis mk2. Playing Pink Floyd Echoes once more. Result? Very similar behavior. Subsonic pumping, strongest in the right channel. Even if the ASR has far less deep grunt in the bass compared to the Aesthetix. I was surprised! Clearly, like Atmasphere said, the phono stage is off the hook. 

Thanks tkr - but I live in Oslo.Thinking about the problem, I thought: maybe it is related to the Telefunken NOS tubes I use in the super sensitive first gain stage of the Aesthetix Io. So I pulled it halfway out of the shelf, enough to get off the top, and swapped the two Telefunkens in the right channel for a new pair of PSVANE 12ax7. Result? No difference. The pumping is still more visible in the right than the left channel. Then I swapped the left and right phono cables leading to the Io. Again: no difference. Right channel pumps more.

Where in Norway do you live, o_holter? If you live in, or close to, Bergen, I can lend you a Soundsmith-modified Denon DL 103 R to test out your theory. It should certainly be low-compliance enough.

Thank you for your patience and help my friends.

Handymann - hire an exorcist – indeed !! I played Crime of the century (Mofi version). Woofer pumping between tracks – yes, some. Much energetic woofer vibration in the loud parts of the music - yes. But it sounds great. You said the Fathom subs “didn’t like it”, what happened?

Atmasphere - the pumping seems to repeat very exactly once per revolution – yes. But why does that point to the turntable, rather than the vinyl? My suspicion is that I pick up vinyl noise. That’s why it varies between records, and why I see it also on recordings made on my former VPI turntable. And why tightening the spindle housing and oiling the spindle made no difference.

So yes, I have a main suspect, so far – the low or borderline low cart-arm-resonance, around 7 or 7.5 hz. I will have to check with a lower compliance cartridge, when I get the chance. I borrowed an Ortofon Cadenza Black a year ago. At that time I was not much aware of the pumping problem (maybe, it was less prominent), but I remember that I felt the sound was more polite, less grunt in the bass, compared to the Atlas (the data of the Cadenza, combined with the SME V, suggests a resonance around 8.5 hz).

Raul – try another phono stage - good suggestion. Maybe the “borderline problematic” resonance interacts with some other factor, like an over-eager phone stage (or some non-optimal tubes in it). I will test with my ASR Mini Basic phono stage, solid state, very decent sounding. I bought it since the Aesthetix Io was a long time gone for repair. But when the Aesthetix came back, the reaction over here was just WOW. So if the ASR pumps less, it is maybe because it is more anemic or polite. The Aesthetix is known for its explosive dynamics and it goes down real deep. I will check.

All in all, I am learning to live with the problem...enjoying the music, but also, not giving up, the mystery will be solved. Music mainly sounds great. There are no “obvious” signs of rumble. I have a suspicion that the subsonic pumping I see between tracks has a negative effect on the music, but I don’t know this. If it had been really bad I would have preferred playing digital, but I don’t.

A final observation. The pumping is more visible in the right than in the left channel (in my home system, at least – not sure about the cottage system). No idea why.

@o_holter , if its happening once per revolution regardless of the LP, its a defect in the turntable. Could be a bad bearing (which is why I specified grease earlier, rather than oil), could be something that rubs on the platter or it could be the platter out of balance, and shifting on its spindle as it rotates.

The preamp is clearly off the hook. To test this I would simply borrow a turntable, it does not have to be expensive, just to try out.

O_holter: Sorry I misunderstood you, conerning the bump during cd playback.  Since it's only when playing vinyl, common sense dictates it has to be in your TT.  Too bad u don't know someone who could bring their TT over for an A/B comparison.  Good luck. I'll be very interested to know what u find.                                                 Steve in Tennessee. 

Dear @o_holter : ""  full SS phono pre - yes, good idea. But again, I wonder, if this would solve the mystery. ""

you will know when you try it. It does not needs to be a top SS unit because is only to make some tests.

If you have the opportunity to do it then you must to do it. You can lost nothing but time consuming.

R.

Yes I will tell, once I find the culprit. The subsonic pumping does not occur with CDs, only vinyl. It does occur when I play digital recordings (rips) of my vinyl. Since these were made with zero speaker volume, acoustic feedback is unlikely. As I've said before, my phono preamp needs balanced out, single ended sounds far less good, so the single-ended KAB would need some kind of cludge to work. If KAB had lived next door I would of course have tried it, but it requires ship across the atlantic, tax etc - for what probably degrades the sound even if it takes away rumble.

If you’re hearing a periodic bump and it’s keeps a perfect rhythm, has to be in your transport, except you said it does it on cd too. 🦄

Another thought, you may have a bad crossover in your speaker, but that would have to be both speakers failing and that’s very unlikely, but virtually everything you’ve described makes no sense. Don’t get the wrong idea-I believe you, it just doesn’t add up. You’ve invested many hours in posting and trying suggestions.  I feel your pain. Pls try a filter.  If that doesn’t work, you must be in the Twilight Zone.  No disrespect intended. It’s just too crazy.  🙃

O_holter. As I said and agree with CT_0517-I think it acoustical feedback going back into your cartridge. Today I am trying some new phono interconnects and they’re shorter, so I had to take one TT off my “floating” support platform and placed it beside the speaker.  My TT platform is on my left side wall.  Anyway put on Supertramp Crime Of The Century, which is not that bass heavy. No main speaker woofer pumping, but my two JL-Fathom 113’s didn’t like it at all. I was convinced your problem was acoustical, but I read you experienced almost the same problem with cd’s and that it had a rhythm to it like going over a road with expanders in it. Bump...bump... bump...etc. If this is what you’re experiencing, it has to be TT related-except you said you heard it when playing a cd too. My advice-hire an exorcist. Can’t see anyway you can have the sound in both cd and vinyl playing. If only in vinyl, you will probably need a subsonic filter, as I said before. You can always build an isolated floating table, as I did, or buy a TT platform designed for high tech precision instruments at around $5K😳. Please keep me informed. I would like to know what solved your problem, if you find the culprit.

Again, think KAB rumble filter with RCA to XLR adapters.  Problem will be solved with no detrimental effects.

"The highlighted noise on the LP playback, approximately 7 Hz, is absent on the CD. By the way, the very low frequency noise was present on every LP I played for this test: from new pristine vinyl to older worn LPs with more clicks and crackles."
https://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=99388

Dear Raul, thanks!

1)
The speaker system is Audiokinesis, Dream Makers in front, plus LCS speakers firing towards the roof, in the back of the fronts.
Similar to this one (but in much nicer light wood):http://www.audiokinesis.com/dream-maker-lcs.htmlThe frequency response is down to 20hz or lower in the combined system, not sure. It goes deep, that's sure.
But if speaker energy into the room etc was the main culprit, I would NOT have woofer pumping on my vinyl recordings (made when the speakers were off) - and I have!
2 Borrow full SS phono pre - yes, good idea. But again, I wonder, if this would solve the mystery. If it was related to the phono pre, the pumping should appear, depending on the volume. But it doesn't. It only appears when the needle is in the groove. More or less, depending on the vinyl record. Usually - maybe always - in EXACT repeat, each turn of the record.

The pumping pattern seems to follow its own logic, different from the normal vibrations and excitations of the woofer. As stated above, it is less obvious within than between tracks. This evidence suggests that it does indeed relate to the cart - arm match - it has too low resonance, and picks up too much down-below vinyl excitations, for some tastes, or just "good enough" for other tastes. The whole system goes deep down.

We played Pink Floyd: Meddle, the intro number, with the hammering bass, and noticed that a bit of pumping was still there, but NOT in time with the bass notes, but repeating - like before - in a once per revolution pattern.

Dear @o_holter : Two question, how is conformed your system speakers and its frequency response? is a passive design or active? two subwoofers or none? well more than 2 questions and other one.

I posted before that could be a good test to try to borrows a full SS phonolinepreamp instead buklbs you are using. I think you have to have that test, is a must.

R.

My audio friend Eirik came around today and helped me tighten the housing of the spindle on the Hanss player. Luckily the needed 2.5 mm Umbraco driver was included in the set I had bought. So - what was the result? Pumping: no difference. It did not go away. Sound: maybe a tiny bit more relaxed, less tense, but this may be my imagination. Eirik brought along some fine-sounding records and we played tracks from the Mofi edition of Dylan's Another side, and from the reissued Grateful Dead Cornell 1977 box. They sounded very good, and neither he nor I could find any clear indication of too much rumble. But he did remark on the LOOKS - the visual (subsonic) pumping of the woofers especially between tracks. It does not look like that in my system, he said.

My short summary, so far.
Vinyl rips from my main rig, made on my DSD recorders, played back at my modest cottage system, are able to reproduce subsonic pumping. When I play digital including advanced digital at the cottage system - SACD - there is no such pumping. With vinyl yes, some pumping, varying with the record.
This seems very similar to my findings, regarding my main system at home.
The pumping seems to happen with the cart-arm combo regardless of the player (VPI vs Hanss) - although I have not checked this much.

Atmasphere - thanks for hanging on, what would A-gon do without such good advisors.

Today I received the millimeter version tool that should help tighten the housing of the Hanss bearing. When I get my friend over we will turn the whole heavy player on its side and then try to tighten it. We will also give the bearing a bit more oil - this should be just thin "sewing machine oil", says some audo importers over here - Hanss does not specify.

My suspicion is: it won't make much of a difference. But we'll see.

Just as a FWIW- the digital recordings you made may not have the subsonic information that is pumping your woofers, so I would not use such recordings as the results might be inconclusive.
Have you tried greasing the platter bearing yet?

Back home testing woofer pumping on Pink Floyd: The Wall, the dreaded thing happens, my neighbour (house is vertically divided) rings my door bell and asks me to turn it down PLEASE. It happened after I played the "shotgun" drum/bass effects in the intro - "there were certain teachers"...Another brick in the wall. Volume close to the wall to the neighbour maybe 92db.
Since it was early evening, not late at night, I went over to him, rang his door bell, and protested. They have lived there for 4-5 years and not complained before. The dividing wall is sturdy cement you took away some isolation. Etc. But - well - I guess, no more woofer testing, at the moment.
I HATE the feeling that my music "bothers" someone else - don't know about you.
 

Back testing my cottage system playing SACDs. System is good enough to show the considerable step up from CD sound. Almost as good as my vinyl rips. And like before - with digital sources i see no pumping.

Conclusion so far - maybe, just, live with it, until the next cart change.
Facts:
- Pumping carried over to the secondary system - clearly not amp or speaker dependent (digital LP recordings).
- Arm bearing, turntable, drive, belts etc - no indication of misbehaviour
- Maybe the leeway in the Hanss bearing plays a role, I will know soon when I get the tool to tighten it (i doubt it makes much of a diff, based on testing so far) - including: if the Hanss misbehaves, why do I see pumping also on my VPI HW19 recordings - ?
- Getting a balanced filter seems difficult. E g the KAB single ended filter would need an extra box. This combo (or cludge) would probably not be good for sound quality, compared to direct balanced.
- I suspect that a rumble filter, properly installed (in the phono stage) might help my sound.
- I see woofer pumping clealry before or between the music tracks on the LP, with the stylus in the groove. This goes on more or less, depending on the LP. The pumping is clearly related to the revolution of the record, it repeats once per cycle.
- When the music is playing and the stylus in working within the music track, I don’t see much pumping. I suspect that this is because the woofer is now in the grip of the musical energetic vibrations.
- However, it may be that the woofers are still made to "work" down below in ways not optimal to the sound. In simple terms, more stress, less peace. Not sure.
- I have a feeling that woofer pumping is related to more listening fatigue. But I am not sure. Testing different records, I also find a bit of the opposite rule - pumping is related to good, involving sound.
- If I had serious "underlying pumping problems" with analog/vinyl, I would have selected the digital source, in my system (since digital music shows no pumping). Yet that’s not the case. Digital music sounds much poorer in my system. More harsh and flat - and not much more "peaceful". Although this may also be due to the fact that my analog chain is better than my digital chain.

Testing DSD recordings made by the same cart-arm combo on a different player, the VPI HW19, some years ago. Not quite the same, since the recording was made with the Lyra titan i cart, not the Atlas. Yet they have the same compliance and should behave fairly equal.

Is there woofer pumping? Yes some. A bit less? Maybe, not sure yet. The jury is out.

Listening to my older recordings, I hear a poorer recording and flatter, more restricted sound than with my current Tascam DA-3000 recordings (and direct vinyl playback). Not strange, these recordings were made by the little Korg MR-1, punching above its class, but still limited, with single ended connections while I now go balanced, to the Tascam. My general impression is: when I went from standard DSD recording (Korg MR-1) to double speed DSD (Tascam DA-3000) I clearly got better sound and more bass. But maybe a bit more woofer pumping too? I am not sure. I will have to check this out.

Yes - or simply, the vinyl groove noise...

I would grease the platter bearing and see if that makes a difference. If it helps, I would consider replacement of the bearing unless grease is an acceptable lubricant.

The fact that its happening in time with the rotation of the platter (as you stated earlier) points to the platter bearing.

Back home, some more testing on main system:

Audiotomb suggested an arm bearing test. I set the SME V so that the arm floats, zero weight and zero anti-skate, can I lift it with a light feather? Yes. Movement is vertical, not slanted? Yes. Can I drop a 1 cm square piece of paper on the top of the cart, and the arm sinks? Yes. Can I blow the arm vertical and lateral? Yes. Can I  wiggle the arm base, is there any slack? No. Conclusion: arm bearings probably OK.

Stingreen - support is a heavy stone rack, but sure, I can try a wedge.

Atmasphere - I guess you mean that there could be a turntable issue even if the pumping is more evident on some LPs than others. I have ordered the tool to tighten the bearing shaft/housing on the Hanss, but have not received it yet. So I have no way to check directly. Come to think of it, I could try to find some DSD recordings made with the same cart and arm, on the VPI HW19 player that I used before - this should clarify the issue. If it is a turntable issue, I shouldn't have pumping on recordings from the VPI - right? (But my inner audiophile says: if things were that simple...)

Since degree of pumping varies with the LP and repeats precisely with the record's revolution, drive problems probably is not much involved - confirmed by cleaning belts and adjusting the player - no big difference.

This comment really suggests an issue with the turntable despite the belt cleaning (which would not address something like this).

Have you tried solidifying your support table to the wall with an appropriate piece of wood wedged there??  

Ct0517 you are right - i’ve installed two beams in the cellar under the rack - I hammered them into place, a horizontal plank on top of each - it makes a lot of difference - i can jump in front of the player without mistracking. This, and separate el to the system, are among my "no looking back" mods / tweaks.

I have been thinking: the main culprit is the cart-arm combo's low resonance. But is it? Much is in the blue, since the HFN test record is known to be somewhat problematical (e g dont use it to set antiskating), calculators may be crude and we dont even know the exact cu at 10hz for the Lyra. It is 12 at 100 so MAYBE 18 at 10. Or 20 or 22. These numbers make a difference in the calculators.

The basic idea is that the pumping would stop if I change to a lower compliance cartridge - or to an arm with less effective mass. Then the HFN test would presumably show a resonance at ca 10hz - where we want it.

The Kuzma 4point is three grams more mass than the SME V. It should have even more resonance problems than mine. Yet Michael Fremer declared the 4point/Lyra combo so good he could not get over it. It seems that the Atlas sounds good with more arms than the calculators and test record would suggest.

o-holter

if you have addressed the turntable, and your amplifier is not blowing its brains out, then it leaves one thing - acoustic feedback. 
what is under the hard wood floors in your room. Do wood beams run under the floor ?   

It seems that to use the single ended Kab filter from the balanced outputs of my phono stage (having tested that these sound better than the single ended outputs) I will also need a converter box. It becomes complicated.  If KAB was next door of course I would have tried it by now, but it means shipping across the Atlantic and maybe taxes just to have a try. Kevin at KAB has been helpful.

Update: situation in the system at the cottage seems like with the main system at home. Vinyl records including DSD recordings of these made by the same cart-arm-phono-preamp in the main system, create pumping, more or less. Its not just Meddle, but e g Glass and Shankar too and Sade: Love is... When I play digital from the Oppo player I have here - no pumping so far at least, testing SACD Moody Blues: On the threshold, and CD Spirit: Sardonicus.

There is pumping with vinyl but maybe it disturbs less with the smaller speakers and less linear amp here. I also note that there are more energetic vibration from the vinyl (slightly touching the cones) compared to the sacd and cd. My ears tell me I prefer vinyl - this is why i bother to make recordings. 

Audiotomb - very interesting. I think my arm floats fine but will check when i get home. The HFN record lateral test shows very visible and sonic resonance ca 7hz while the vertical test is much less obvious (the test tone warbles a bit between ca 10 to 5hz).

"If you have rumble problems, get a light feather!" Who said this hobby was boring?

I had significant woofer pumping

https://forum.audiogon.com/discussions/rumble-issues-see-old-thread-update#1559764

Tried everything

then did the feather test

a light feather should be able to move a tone arm

the bearing in my tonearm wasn't moving vertically

all the movement was the cantilever going up and down creating the woofer pumping

I am mystified. Why do i see woofer pumping playing Echoes on my small cottage system which is 6db down at 42hz and probably not audible below ca 38hz? All hail to DSD? I play a rip / recording of the same original vinyl that gives pumping in the main system. Recorded in DSD on Tascam Da3000. Playback by the little Fiio x3 player, which does native DSD, to a Ming Da integrated tube amp and Aurum Cantus Leisure 3 SE speakers. All very good but i seriously doubt if this system is capable of doing anything down at 7hz where my cart-arm resonance problems are.

Handymann - much appreciated and relevant. I did a lot of platform and feet mods with my Vpi Hw19 to good effect but mods have so far little effect on the Hanss t30 with its maglev feet. And - my vinyl recordings are made with the main speakers silent or very subdued. So I doubt acoustic feedback is the main culprit in this case.

The woofers on the Aurums are smaller but the behavior is similar to the Audiokinesis woofers. Some sound related vibrations but also pumping in and out. Yet I dont hear this movement at least not directly. Using my fingertips there is energic quick vibration that I hear but also a slower pumping that i dont hear. 

 Listening more, the experimental nature of Echoes and the whole Meddle album shines through. In other words it may well be that they experimented also in the low frequency range. They used Shepard tones and invented seagull squeals, I read. It is one "flowing" album and the silences between the tracks are not just silence but e g wind blowing too like at the start.So it is maybe a quite special case.

O_holter:  I'm convinced your problem comes from acoustical feedback. With a TT, placement is vital. I too had the same problem.  After months of experimenting, I found that TT platform isolation cured my problem. I built a suspended platform using heavy duty dampened springs and cables. (my room is on a suspended floor on the upstairs portion of my house that exasperates the problem)  I also noticed feedback on my Theta Miles CD player, when playing anything with a lot of elf and high db levels. I installed four steel cones on the bottom of the player and now I enjoy outputs of 90 db+, without any adverse effects on both playback systems. Most rooms have areas, where the low frequency is somewhat exaggerated. Be sure your TT, as well as your CD transport is not in one of these locations. 

I notice that Pink Floyd Echoes recorded from the LP on my system pumps the woofers also on my cottage system! 

Thanks Atmasphere - yes the low reach of the amps in combo with the speakers  may play a role. But with the Triplanar you dont have the problem. Do you know the resonance of your arm cart combo?

Lathes - low frequency - ok - but if it happens between tracks why not also within them? I can see the pumping between tracks on my 'energetic' Lps. Not much within the tracks but i think this is because the music energy takes over the woofer. It does not show much but is still there. Giving more stress in the music. Just my suspicion.

Since degree of pumping varies with the LP and repeats precisely with the record's revolution, drive problems probably is not much involved - confirmed by cleaning belts and adjusting the player - no big difference.

Electronics bandwidth is an issue too- your amps are full power to 1Hz. Most tube amps can't go anywhere near that low.

But I have similar bandwidth with both the amps and speakers at home, yet don't experience this issue. I am using a Triplanar, which allows for a bit of adjustment of the mechanical resonance by using multiple weights for the counterbalance. My 'table is different too.

Its true that some lathes can impart low frequencies to the LP, but that usually occurs between tracks and also at the end, where the carriage for the cutter head is advanced at a higher rate than during a cut. It sounds like you are getting this pumping during cuts on the LP, so I would rule out the LP as the source.

I would try applying a light grease to the platter bearing, to see if it shuts it up. If so, I would be thinking that the platter bearing is worn as normally a light oil is used.

Listening to vinyl rips from main system, on my cottage system. No pumping of course - the Aurum Cantus speakers only go down to 40 hz or so. So music is limited but it also sounds nicely peaceful. No harm done - sins of omission not commision in the bass.

I think beyond the low cart-arm resonance we need to add the very fullscale speaker system in my main system. Four speaker Audiokinesis. Lots of woofer power. - Maybe other speakers is why some users and reviewers dont experience much problem.

I already know that using single ended outputs from my phono stage curbs the pumping compared to using balanced outputs. But it also sounds much poorer! So to give the KAB a fair chance it would need an xlr to rca adapter (thanks, stereo5). Not sure if an additional adapter is needed to the Einstein preamp it seems xlr and rca inputs sound the same.

Thank you miner42 and stereo5. It may take some time, but i wish to try your suggestions. Although changing the arm or the cart might be optimal, no one so far knows for sure what works best in my system. 

+1 miner42

Just a thought, what if you used RCA to XLR adapters? BAT makes some excellent ones. I have an original Harvest first pressing of DSOTM and the bass is very taut and very deep with no woofer pumping.  I also have a MFSL pressing which for some reason is much lower in volume with no pumping.   I wish you lived close by, I would let you borrow my KAB filter to try.

Another KAB RF-1 user with great results.  VPI Aries 3, Ortofon Cadenza Black MC, Manley Chinook SE, McIntosh pre and amp, Sonus faber Cremona Auditor Ms, REL B1.  Glorious music.

Pink Floyd LPs  - a  quick test of woofer pumping
1 The original LPs from the first years, not so much, deep sound is not recorded.
2 Notably more deep sound - increased pumping - overall sound is better - step by step - on Atom heart mother, and early 70s LPs - reaching a climax on Meddle
3 Less woofer pumping but also somewhat limited, anemic sound on my remasters of Dark side of the moon  (i dont have the original here)