Why are my woofers pumping?


The other day, with sunlight direct from the side, I noticed that the woofers in my speakers are pumping in and out, much more than I was aware of, when the stylus is in the groove, even between tracks (no music).  I can see it, even if I don’t hear it. Why does it happen? The woofers behave normally (no pumping) with digital music, and when the stylus it lifted from the groove, so it is not the speakers, amps, preamp or phono stage. 

I’ve read that the typical reason for woofer pumping is that the cartridge / arm resonance is too low.  I tested, with my Hifi News test record, and yes, the lateral test puts the resonance at 7 hz or so – too low (but I’ve seen some doubts about the results from that test record).  It is strange, since the combo I use – Lyra Atlas cartridge and  SME V arm (on a Hanss T-30 player) is supposed to work well. I tried to strip my arm of extras, cleaned the damping trough, etc – but it did not help much.

Anyone has an idea, why it happens, or what to do about it?  


Ag insider logo xs@2xo_holter

A few months before I noticed the woofer pumping with the 2013 Atlas, it was in for a check at a local service shop. Soon after I noticed the pumping, the diamond dropped from the cantilever. So it *may* be that it received some tough handling at the shop - and not from my records, even if some of them were dusty. I will never know for sure.

Just a little update. Testing Pink Floyd: Echoes, with the Lyra Atlas replacement I got back in August, 2018. Could it be, that the pumping woofer syndrome is caused by wear of this cartridge? Short answer: no. The new cartridge has now run ca 1200 hours. I don’t see or hear any problems. The woofers DO show subsonic energy (they move/vibrate although I don’t hear sound), yet it is nothing like the heavy pumping I had with the 2013 Atlas.

I think the diagnosis is fairly clear here. First, this is a really wide frequency recording, especially in the opening section, and therefore, a good diagnosis tool for lowest bass performance (the treble is extended too, exceptionally life-like). Your copy of Meddle may not have this - it concerns my second press, cut by H T Moss at EMI UK). It was made to challenge your stereo.

The reason why it created woofer pumping was mainly related to the poor / worn state of my 2013 Atlas cartridge. The arm, player etc had nothing to do with it. A few months after I discovered the woofer pumping, the stylus fell off the cantilever. For no clear reason. I think it had received a bump or shock earlier - from a not so clean or dusty record - and that the woofer pumping was the result of that. It had got loose. I cannot prove any of this, but it seems the most likely explanation. Needless to say I have improved my record cleaning. Even if a record looks clean, I always use a Mofi brush before play. A little speck of dust, or a hair, can be a big hurdle for the stylus.

 

Hi rdk777This agrees with my own experience, especially regarding the VPI HW19 player I used before. Every little thing I could do to it, regarding the platform, feet, etc, made a change. Air (bike tires), a large bright star sand box, ceramic feet, you name it!
Now, with the maglev system of my new player, Hanss T30, it does not seem so tempting. It rests directly on my very heavy stone rack. Maybe HRS might improve things  even there. I note that Aesthetix recommends HRS feet under their boxes (like my Io phono stage).
Hi-

I had the exact same issue with a Kuzma Stabi R table, 4P arm and ZYX Universe II cartridge. Initially, I just had it on my audio rack and the pumping was really bad. Then I added a HRS R1X platform and it got better, but still there.  I called HRS and they suggested replacing the regular feet with low frequency feet. Also was communicating with Franc Kuzma who agreed with HRS and said the reason was that the table and audio rack got into an acoustic feedback resonance. Just got the feet from HRS and it seems problem is solved now - overall sound also significantly better.
Maybe. I did a new round of tests. The new Atlas not only sails happily along the trail without any silent woofer pumping (or mistracking), it also reproduces my stress tests cuts beautifully, including Pink Floyd Echoes and tracks from Rickie Lee Jones: The evening on my best day. Passing with flying colors. 
Thanks mijostyn. I like it with all kinds of music. The effect is  that I enjoy listening more. I wonder if it actually sounds slightly better than my former Atlas did when new. Possibly the low output version (Atlas SL) is even better, but I can't risk it with the Aesthetix Io phono stage, which likes the 0.56v output of the standard Atlas. 0.25 or thereabouts may be too little for the Aesthetix to sound its "robust" self. At least if using NOS tubes, like I prefer, even if I get a little more background tube noise. Lyra warns that the SL version is not for everyone, the phono stage must be up to it, or you should use a stepup. However, Aesthetix says no to using the Io with a stepup device, don't do it. I think this would destroy the purity of the design and be a waste of money. I tested with a Jensen stepup some years ago, and this confirmed their point. Tubes all the way = best sound, no doubt about it, to my ears. I think the Atlas feeding the Io is a very good match. Some have complained that the Atlas is a bit hard and harsh. Or a bit bright. I don't hear much of that. Rather, the tonal balance is spot on, meaning that the "character" of the cartridge is very hard to identify, since each LP sounds different. I am not saying the Atlas has no faults, but usually, they turn out to be faults of the LP production, or "to the limit" type production (cf Pink Floyd Meddle), or the LP itself (wear), or my turntable setup isn't 100 percent, so whenever I think I have a problem with the cartridge, it disappears on a different type of LP / music /  or with setup tuning. In all, the Atlas/Io combo works great. And the Atlas sounds better on the Hanss T30 player than I ever managed with the VPI HW19 (using the same SME V arm).  
Good luck o-holter. I do have a soft spot for that cartridge. It is totally unbeatable for things like string quartets and not bad at all for rock.
My former Atlas, made in 2013, was used successfully over a period of several years, before it broke down, after five years - the needle saying goodbye to the cantilever, for unknown reasons. No mishandling on my side. Although the leaning of the LPs was so-so. My first cartridge became non-optimal, after long use ca 1000 hours, and it remains to be seen if the new Atlas extends the score.  
One more update for all my Audiogon friends. The newly replaced Lyra Atlas cartridge sails through my stress tests without problems. I play Pink Floyd: Meddle, and the woofers react a lot, yes, but they dont over-react. The silent woofer pumping is gone.
mijostyn
... the SME V is a very light tone arm ...
Not really. The mass of the 9-inch SME V is about 10 g, which while on the low side, is certainly not "very low mass," especially when compared with something like the SME III, which is about 5 g or so.
O Holter, the SME V is a very light tone arm. The Atlas/SME combo is fine. 7.5 Hz is a touch low but not low enough to cause trouble. I believe you have said that the woofer pumping is different with different records. 
I'll assume you have not beat your turntable with a sledge hammer. What you are seeing is rumble pressed into the record. The lath used to cut the record is rumbling! I have seen and heard this in a number of so called 180 gm audiophile pressings. Some of these companies are using old hand me down lathes that have been moved around and damaged. If the rumble happens to be around 7.5 Hz your tonearm and cartridge will amplify it. I use a digital subsonic filter. Just for fun I turned it off and played some of those bad pressings and sure enough my subs were flapping around like drunken sea gulls. 
The resonance is a bit high - 7 hz ish
That's on the low side. The window is 7-12Hz.
Hi mijostyn
Too light? I have not thought  that adding mass / weight to the Sme V would help. Seems that the Atlas sounds better without it. The resonance is a bit high - 7 hz ish -  using my hifi news test lp - but to get it down I would rather have to reduce the total arm and cart mass - or am i wrong? I am away now but will test your 'add two grams' proposal soon. Thanks!
Get a test record with vertical and lateral resonance test tracks and see what happens. 
Holter, The SME V is too light for the Lyra Atlas, a cartridge of intermediate compliance. I suspect you are seeing the woofer take off up between 15 and 20 Hz. Add one or two grams to the head shell and let us know what happens. 
Update: I have got a replacement for the broken cartridge, and I am very happy with the performance.

Some testing: The new Atlas makes it clearer that the subsonic effects (and possibly, the subsonic woofer pumping once per revolution) is part of the intended sound, e g in the introduction to Pink Floyd: Echoes. It resides in the recording (or my pressing) and is not in a fault in the system, even if the resonance frequency of my arm and cart is a bit low / challenging, so everything happening down at the end of the frequency scale is picked up.

I don’t hear much rumble or other unwanted effects, just a marvellous big soundscape.

On Rickie Lee Jones The evening, I no longer see any clear subsonic woofer pumping, just a lot of energy, in the woofers, coherent with what I hear.

So it seems, especially with the new Atlas - just look away from eventual woofer pumping (as long as the woofers don’t complain), give it a go, and enjoy the superior sound.

Pink Floyd’s Echoes is known to include "subsonic" effects. Maybe once per revolution - like they later experimented with heartbeats, on Dark side...or maybe on Echoes this is a not intended side effect, who knows. I have an early second pressing of the Meddle UK original, matrix side 2 (with Echoes): "SHVL 795 B-6" "11"? "1" and handwritten "HTM". HTM means Harry T Moss cutter extraordinaire at EMI UK. I have read that subsonic effects may happen due to record warp, but I cannot find any signs of this, with my copy.

Does it sound good? You bet!
I thank you all for all suggestions in this thread. My problem of woofer pumping is 'solved'. No diamond, no pumping. No woman no cry. Maybe, it was mainly a result of usage. It has 1200 or 1300 hours use, in my estimate. I will try to fix the Atlas. But this thread is now at rest from my side, since the problem is gone.  
Nothing so bad it isn’t some good also. I am trying to find a way out, how to repair it for a reasonable cost. This should not happen, for a moderately used (not misused) cartridge. Such things - diamonds falling off, cantilevers breaking, cantilevers or diamonds not precisely tuned - are known to happen, across cart makers. As users we hope for better quality control and follow-up when sub-optimal units have been sold.

I think we now have a very clear main suspect, not suggested by anyone in this otherwise very rich thread. That is: 1) the Atlas showed increased signs of woofer pumping, over some months. Abnormal, when comparing to the Clavis and Titan. 2) For a short period, the diamond was half-loose from the cantilever, with blurred sound. 3) Next, it broke off, from the cantilever (this happened through normal, careful handling)  All this points to a gradually increasing defect in the diamond / cantilever connection. Assuming that a potential crack or breakup can indeed give some strange bass / subsonic pumping effects at first. I am no engineer, but it seems highly possible, and fits the data in my case.


Dear @o_holter : Sorry to hear that.  That happened to me twice and I remember that in a trip to Houston in a firned home place just when we wanted to listen his great audio system suddenly the stylus tip just " was not there ", by coincide was a Lyra too: Titan .

R.
Oh no. Worst case scenario. Trying to fasten the lead clips to the Atlas, to get it back on to the arm, something has gone wroing. Cartrudge first gave strange distorted sound, we adjusted some more, but then it just sailed across the record. Cause - no diamond. It is gone. Without any external hits, stresses etc that we can see. Maybe it just did not like this thread. Anyway it is no longer there. Atlas - caput.
Dear @o_holter : ""  But the results - so far - are more one of a kind. The Atlas pumps, the others don’t. This makes me suspect suspension wear or some other non-optimal condition in the Atlas. ""

As I said in my posts you had to test your Clavis, that could be interesting to know about and now you already know why I told tou what I told you. Fine.

R.
Since I am testing mainly for subsonic woofer pumping the sonic impressions may be less relevant, but the experience is clear and maybe interesting for some of you. Listening in "retrospective" to the Clavis DC, allthough it sounds good, I have two problems, one is the limited soundscape, the other is the harsh almost digital type of sound in dynamic parts of the music. But if I had known no better I would have loved this cartridge - and I did, fifteen years ago! The Titan i that I got ten years ago was clearly was a major step up, from the Clavis - and it sounds very good today also. The soundscape became much wider and bigger, more width and depth, refinement and detail. The Atlas is some steps above the Titan. The wider and deeper soundscape was present with the Titan, but the Atlas improves and tunes it better so it sounds more natural. No looking back...
The observant reader may ask why I did not try the Clavis and the Titan before, since I had them at my loft. That would have saved us a lot of speculation in this thread. The answer is that I thought they were broken, due to many hours on the Titan, and a cantilever problem on the Clavis. But both are playable, and good enough to test for woofer pumping.
"what I hear, it is fast vibrations, not pumping" - this needs a clarification.

What exactly is the symptom? With a better cart - changing from Clavis to Titan - I hear / see / touch woofer behavior changes (method described above: fingers slightly touching woofers, observing, listening). The woofers are more energized, asked to do more. The better cart offers more musical information, deep energy, etc. This "normal" energizing is quite easy to observe - you hear it as you see / touch it, and it is normally a fast movement, the woofer "shivers". Mainly (not always) what you see is what you hear. Sometimes there is woofer movement not clearly linked to sound, but it follows the same main pattern and is probably not serious.

The see/touch (you dont hear it) pumping is different. It is slower, more stately, rather than quick vibrations. It follows, more or less, a "once per revolution" pattern. There is no clear relation to the music, and it is easiest to see when the stylus is in the groove between tracks. The pumping is less observable when music plays, but there is (so far) no indication that it is "turned off", it is still there, but working in the background.  
Testing the Titan i (ca 2008 model).

To my surprise, there is little to no subsonic pumping. Much like the Clavis. Or maybe a little more. But clearly different from the Atlas. The woofers are more engaged, more vibrations, changing from Clavis to Titan - but this fits what I hear, it is fast vibrations, not pumping.

Sonically the Titan is a clear step up from the Clavis (today, also) with wider, deeper, better detail, better e g on female voices (R L Jones: Evening..). On Pink Floyd’s Echoes, the soundscape is now almost as large as with the Atlas, although still a bit more harsh, less natural, with some sibilants (I could cure some of it through adjustments).

I had expected a gradient, according to resonance theory. The Clavis should pump least, the Titan some, and the Atlas most.

But the results - so far - are more one of a kind. The Atlas pumps, the others don’t. This makes me suspect suspension wear or some other non-optimal condition in the Atlas. Yet I was surprised to find no signs of pumping with the Titan - since this has been used maybe 500-800 hours longer than the Atlas, so if suspension slack, wear and tear, is the culprit, it should show up there. But no.
Back to testing.

I've brought my (quite worn)  Titan i down from the loft. And will connect it soon.

Since the Clavis creates less pumping (next to none), I would expect that the Titan comes in the middle (if the resonance theory is right). This is due to the weight differences (assuming that the 10hz compliance is much the same, maybe 21, as suggested earlier in this thread). The tonearm effective mass is 10.5g, the two screws add 1.1g (I measured), the Clavis 9.5g. This gives a 7.6 hz resonance, according to the calculator. With the heavier Titan at 10.5g, there should be a 7.4 hz resonance. And with the heaviest Atlas at 11.6g, a 7.2 hz resonance.

This fits somewhat with my results, but I wonder if the compliance of the Clavis is in fact lower. Since woofer pumping goes from visible and maybe a problem with the Atlas, to not much visible, with the Clavis.

It may be that the wear and tear on the cartridge suspension plays a role here. The Clavis has only 200 hours, the Titan maybe 2200, the Atlas 1600 (rough estimates). My audio friend Eirik remarked that he had not noticed this pumping problem earlier, in my system. Myself, I am not sure, it may have been going on as long as I've used the Atlas, only we did not look for it, or it may have become stronger over time. I remember that, as the Titan became more worn, I had some rumble and bass problems, but I am not sure if the Titan was the culprit.

So it will be interesting to reinsert it into the system and hear how it compares with the Atlas. Like I've told you, ten minutes with Clavis made me think, this is decent, even very good - and then I ached to get back to the wider and deeper soundscape of the Atlas. Pumping woofers or not. The Titan should perform in a middle zone, but closer to the Atlas.



I was maybe a bit optimistic in my last post. The thread is all over the place, yes. But so are most of the threads I’ve read on this subject. Compare this one: https://forum.audiogon.com/discussions/the-arm-cartridge-matching-myth . Halcro argues that resonance means ca nothing, others don’t agree, kirkus has a good post stating that resonance is only a rough measurement, the cart-arm-combo acts as a high-pass filter. For an even more esoteric discussion, compare this: https://forum.audiogon.com/discussions/strange-tonearm-tweak-long
Invictus005 wrote: " 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?"
Let me posit this in a positive way. "Sound is good. Relax. With a good cart you get some vinyl pumping. Look away". Ok? If so, I agree. Fits my evidence, mostly.

But the thread, even if ignorant or repetetive, is not ridiculous. A large list of potential problems, regarding low rumble and woofer pumping, has been listed and described. Even if low cart-arm resonance is the main culprit in my case, the suggestions are interesting on their own, for anyone investigating low frequency vinyl problems in resolving systems.


Dear @o_holter : Nice result you experienced with the Clavis ( that ovbiously is not even a " small " challenge for the great Atlas. ).

""" So the "subsonic overwork" of the woofers seems far less. Or mainly absent. """

Either the Clavis/Atlas compliance and weigth puts the resonance frequency in the " green " territory as you said. So, seems no trouble for that and very specific tonearm/cartridge resonance frequency issue.

I imagine that you already tested both cartridges using the SME V in static and balanced way about the VTF set up.

Your Atlas has over 1,500 hours of use that are not way higher but not way low number.
Trhough those 1,500 hours stylus tip and cartridge suspension are the ones that could starts to work outside manufacturer specs and I’m not saying that’s your case but only thinking " fully loaded voice ".

Who can tell you if any problem down there? not a single re-tipper but the manufacturer it self. maybe time to talk with J.Carr for he can take a look to your beloved Atlas.
In the mid time you can re-tip your Clavis with a re-tipper using boron cantilever and you will be surprised the Clavis improvements.

Anyway, I think you need to try JC directly.

R.


Audiotomb - I already tried the feather test, and found no problem. I also contacted SME who said, basically, if you don’t notice a problem with the V, it should be fine.

Raul sensibly suggested (going the resonance path, along with invictus005 and others) - test with the Clavis DC ca 2007 model that I have on my loft (not much used, since I soon changed to a Titan).
So I’ve done it. Interesting to hear the sound of the Clavis - from back then. Quite decent.

Pumping? I am sure you’re all dying to hear the result!

First impression: less pumping, maybe only normal woofer energy.
Testing the 2016 remaster of New gold dream. And then, with even more clear result, Pink Floyd Meddle.
There is a lot of woofer energy, yes. But less, or very little, of the visual-only pumping. So the "subsonic overwork" of the woofers seems far less. Or mainly absent.

This seems to confirm the resonance problem view. There are some doubts however. First, there is the possibility that some woofer pumping is actually not a big problem - just look away from it. As was suggested early in this thread. I mean, the Atlas sounds better than the Clavis, reaching further down, more explosive dynamics, wider soundscape. After ten minutes listening to the Clavis, I want my Atlas back. Also I've noted that LPs with pumping often sound good.

 Second, I am not sure of the compliance of the Clavis - is it 12 or maybe ca 20 (due to failure to translate the Japanese 100hz rating). It weighs 2.1 g less than the Atlas, though. According to the vinylengine calculator, even a compliance of 20 is thereby enough to get me into "green" territory. This seems in line with my results. I cannot test with the HFN record since it is on loan to a friend.





one thing to try

play a record Try to move your tonearm on the record sideways with a light feather

if the tone arm doesn’t move sideways
chances are the bearing in the tone arm is rigid causing It to not move correctly

if the bearing is locked up
all the up down motion of the cartridge to the record is occurring via the cantilever not the arm bearing

the cantilever going up and down produces woofer pumping



Best wishes
Dear @o_holter : """   compliance is similar to the Atlas so the test may not tell much........ """"

well, you have a " problem " that till today you don't know exactly the reason or reasons for it. You assumed that cartridge/tonearm resonance is the culprit but you really don't know because you just don't want to make tests as listen the same system with different cartridges ( Clavis DC. ) or with different tonearm that you can borrow from somewhere or some one.

Clavis has same compliance: so what? from where came that can't tell you nalmost nothing?

makes no sense that kind of answers from you because you need to find out ( or maybe not. ) what's happening making different kind of tests and if you don't want to do it then is better to just forgeret about as invictus005 said and try to enjoy MUSIC.

R.
Invictus005 please. What may be ridiculous to you may not be so, for fellow a-gon members. You seem to "know" it all - but where is your actual listening evidence? We're all in this hospital together.
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?
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.
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.
@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.

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".
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 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).
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).
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? 


@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.

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.

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.





 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. 
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.