Why are my woofers pumping?

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 ?   

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.

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.

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

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).

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...)

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.

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

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.

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.

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.

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.
 

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?

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.

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.

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.

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.

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.

"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

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

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.

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.  🙃

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. 🦄

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.

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.

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. 

@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.

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.

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.

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.

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. 

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." 

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.

@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.

@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.

Are you able to turn down the gain on the phonostage?

analogluvr"Are you able to turn down the gain on the phonostage?"

It has become increasingly obvious and apparent that the underlying responsible problem this particular user is experiencing is related to his turntable and possibly although not likely his cartridge/tonearm combination and there is no way that the gain of the phono stage could have any effect influence or ability to correct the problem which the user doesn't seem willing to take the steps necessary to resolve anyway. 

 Turning down the gain on the phonostage may alleviate the issue somewhat, it did for me previously. Agreed it is not solving the problem but it would be highlighting it less. 
 Alternatively it should be easy enough to get a rumble filter made with balanced connectors, you could contact the previously mentioned Dan Santoni for that. Shouldn't be that expensive depending on the level of parts you use. 

Dear friends

Atmasphere, VPI - if the pumping repeats once per revolution, how do you know it is the drive / turntable, and not the record itself?

As shown above - the evidence in my case points to the vinyl. E g the pumping varies from record to record. It would not have done so, if it was due to the turntable. And a number of turntable fixes have no effect. AND vinyl recordings made on my former HW-19 turntable seems to pump the same way! The main suspect is the cart-arm combo.

I hope to test this, with a different (lower compliance) cart, in some weeks time, and will report back.

Clearthink - I do want to resolve the problem! I agree with your line of thinking - I also thought it was a two-component problem (low resonance plus something - possibly a turntable issue) - but recent testing seems to show that this is wrong. It is basically a one component problem - the resonance. I’ve tried a lot of remedies, so far. The turntable is not the main suspect. Please folks, read up on the Hanss T30 players. Not where you would look for rumble (and I have tried).

Analogluvr - good idea. I can vary the phono stage volume (it has volume controls). Basically, up to a point, the more the Aesthetix phono stage takes care of the gain, the better the sound. The sound is fine with the Einstein preamp also, but still, it is a step down (the sound is more slim, solid state, compared to the fat, organic Aesthetix). The best fit, in my system, is ca two thirds Aesthetix, one third Einstein gain, before the signal is fed to the amps.

I tested a bit - Pink Floyd: Echoes, once more - changing relative gain levels. Result: much the same woofer behavior, regardless of the phono stage / preamp mix. Like you write, maybe turning down the Aesthetix "alleviates" the problem, but this is marginal. Basic conclusion, the amount of gain phono stage vs preamp is not a decisive factor.

Once more I note that the woofer pumping varies with the LP. Example: I put on my UK original of Colloseum: Those who are about to die, expecting pumping, but there is little, despite very energetic woofer movement within the music tracks. Is there, still, a part-subsonic rumble, due to the low resonance, disturbing the sound? I don’t know, but it is not very obvious. The bass on this LP seems limited (compared to Pink Floyd Meddle, made ten years after). The problems I hear with the sound seem to relate to the treble, not the bass.

My system has "distributed" bass reproduction. It is not a full Audiokinesis "Swarm" bass system, but goes part of the way, with four speakers reproducing the bass. These can be aligned in the analog domain by positioning and other measures. This sounds better than any form of digital equalization I have heard so far. I had a Velodyne DD-18, but sold it.

@o_holter  Well, I don't know it is the TT as opposed to a warped or otherwise flawed LP.  If the pumping is being caused by the record I can think of only 2 issues: 1) The records are warped or otherwise flawed and you're not going to solve that problem by making changes to your system; or 2) Your system is so resolving at subsonic levels that it is reproducing subsonics that were present at the recording venue.  Once again the problem would not be your system.  I don't recall the LP but I have one where I can actually hear either a subway or air conditioning system on the record.  

Since, however, you have mentioned several times that the pumping occurs one time for each revolution of the LP it would seem an amazing coincidence for you to have that many warped records or that the signal recorded on the master was exactly in sync with one revolution of your platter.

Thank you, vpi. I have no indication that the pumping happens only with flawed or warped records. I think your hypothesis 2) is correct, that is, first the low resonance plus a superb cart picks up subsonics, and next, the system is very resolving and sends it all to the speakers. Note, however, that even my modest cottage system was able to reproduce the pumping.

I don't have test instruments to test if the pumping is exactly in sync. I can only say that the pattern repeats ca once per revolution. This is easiest to test in the outro of a record with pumping. There is a click once per revolution when the lead-out groove meets the circular groove at the end, and I can see (and touch) the woofers pump in a regular pattern between each click. So it seems roughly in sync. Which would be the case with most records I would guess? 

Examples of records with subsonic woofer pumping:Pink Floyd Meddle (UK orig), Rickie Lee Jones: Evening of the best day of my life, Byrds: Untitled (US orig), Byrds: The Columbia hits (Sundazed).

It should be easy to test here on Audiogon. If you have a cart-arm combination with resonance around 7hz, you should be able to see the pumping. (Put weight of arm and cart, and cart compliance, into the vinylengine resonance calculator, and/or test with the HFN test record, lateral compliance track).

Testing Jefferson Airplane Volunteers, the new 45 rpm Mofi edition. Not much clear woofer pumping in the outro. But clear in the intro, before We should be together.

The subsonic woofer pumping seems inherent in the recording itself, picked up by my cart-arm combination. It is not due to vinyl warps or turntable problems. But more, due to recording issues, engineers’ decisions. Sometimes the recording goes way low - sometimes it doesn’t.

I associate the records with pumping with "quite good sound", or even very good sound (especially in low energy music, like on Pink Floyd’s Echoes, in the subdued sections). Not "bad sound". Pumping records maybe go a bit further down in the bass, with an overall improvement factor. Even if I suspect that the pumping is not so good for the music.

It is quite bewildering - testing LPs - Elvis Costello: This year’s model - intro yes, between tracks no, outro yes. JA Volunteers mofi side 3, intro yes, between tracks some, outro some. Liz Phair: Exile side A - some, but rather little. A Parsons: I robot, Classic, intro yes, mid track yes, outro yes - with note "great sound".

@o_holter Very interesting, your last few posts.  I have noticed on some LPs there can be a hum in the runout grooves and have always supposed it was on the record.  I don't see why there could not also be subsonic signals in the runout grooves that would cause woofer pumping also.  Unless the woofer pumping is extreme I'd be inclined to congratulate my self on a great resolving system and ignore the pumping.  If it is bothering you, I suppose you could use a subsonic filter as some here have suggested.  I personally don't like filters because you are just placing additional things in the signal path and more "stuff" you put in the signal path the greater the opportunity to degrade your sound quality.

Dear @o_holter : I think you own a Clavis DC too. Do you already tested with?

Characteristics are almost the same as the Atlas regarding resonance frequency calculations. 
I think you have to test it because you " think " problem is that resoannce frequency tonearm/cartridge behavior.

R.

More surprises: Simple Minds: New gold dream, 2016 half speed remaster - pumping - yes. Procol Harum: Home, UK orig - some.

Thanks vpi. This is my thinking as well. I will first try a different cart, and then maybe, a filter, if I get a money back option. A significant fact in all my investigations so far, is that "pumping" LPs are often very good sounding. Lean back and enjoy it.

Raul - yes, I have a somewhat worn Clavis is on my loft. I could test it. But I think the compliance is similar to the Atlas so the test may not tell much. Let me tell you, I don’t like exchanging cartridges....do I get my former adjustments back...or do I have to start from scratch, for cart adjustments.

This has to be the most ridiculous thread on Audiogon at the moment. Everything and all of it. OP, I told you it’s a problem YOU can’t solve. Just enjoy the music. Some of these things are just part of vinyl. Many comments here have crossed the line of insanity. Seems like some people want to end up in a mental hospital?