" I think I'm leaning more toward living with it than putting something else into the signal path that might negatively impact the rest of the sonic spectrum"
Sounds like a good approach.
I know the positive attributes of vinyl and analog is worshiped by many here, including me to a significant extent, but it is what it is, almost a form of antique collecting at this point, and like most things it ain't perfect.
It only bothers me when I have some old rare favorite record that has particular issues and can't be replaced easily, but in most cases, I can either find a decent fresh replacement that is better somewhere either on vinyl or CD. |
Simpler is usually better, IMO. I'm even bothered by the idea that I would need a step up device if I were to get a LOMC down the road. Somehow I wonder if any improvement over the 20X-H (a very good cartridge in its own right) would be lessened by the step up transformer.
Thanks,
Bob |
Hi guys, I guess you dind't see the smiley face after the "20 pound one square foot..."
Bob#1, if you can live with it ........cool. Dont worry about it! Why correct problems, that are not there?
Though I think for $30 give it a try! It will still reduce the amplification of said freq even though you do not hear them, most assuredly your amps are trying to reproduce them and using up available headroom and giving your amp fits. Whether or not you speakers are able to reproduce these freq..
I tried last night and today with the increase in weight of the tonearm mass, to change the compliance, to lower the resonant freq., and saw/heard no difference. That is not my "problem". At least one that did not "cure" mine.
Bob |
Hi Mapman I re-read your post and saw "isn't" as opposed to "is" as I initally read it. Or something like that. And now that i re-read it........
Bob |
Hello everyone, I also am experiencing, what I would consider, severe sub sonic woofer pumping. I hear no affect to the music and no noise whatsoever. It seams like many here are willing to just put up with it, which I have no problem with. Is anyone else here concerned about doing damage or premature wear and tear to your woofer and/or sub woofer from all that constant movement? |
Markpao,
Best to minimize it as much as possible through better isolation, clamps etc., in that large driver excursions from noise can cause damage more easily than otherwise, and it consumes power to produce noise that might result in amp clipping and tweeter damage sooner, , but it is normal, in lieu of filtering, to always have some of this present with records.
Its something to be aware of, keep an eye on, and manage, but not expect to do away with completely even with high pass filtering. |
Yup it's the nature of the beast
My next phono stage will have an IEC Low pass roll off installed ..If I ever solve the woofer pumping for good I can easily reverse this by changing value of the caps
If the woofer pumping is excessive in the long run you can/will do damage IMHO
I will opt for the lesser of two evils and install a low pass filter |
Mapman,
I posted a response earlier today, but for some reason it dissapeared.
My TT is essentially brand new, so I don't think it's the motor.
I suspect, that Shelter 501 MK II compliance is too high for the Technics arm, and that creates an unwanted resonance. Do you think, that's a valid concern? |
The pumping woofer does not just use up available amplifier power. It gives rise to "Dopler distortion" because the advancing and retreating cone is also reproducing higher frequencies, which are modulated by the cone movement.
Get a rumble filter. Cheap and easy. |
Maril,
Yes, it is a valid concern worth investigating. |
The solution I just got around to using is a good, and easy one, though somewhat expensive. I just a day or so ago changed the equalization from standard RIAA to IEC in my Simaudio LP 5.3 phono pre, which has the filter built in. What a difference! Needless to say, I recommend getting and using a subsonic filter.
Dan |
Here's an update. I bumped into Michael fremer. he suggested adding some Bluetac or Moretite to the headshell, effectively increasin the mass of the tonearm and changing the compliance. unfortunately this didn't change anything.
another suggestion was to take the TT off the rack and put it right on the floor, to see if there was some rack related issues. No dice.
Another friend, Wes Bender, has a VERY high end system (Hanson's, Redpoint TT, etc.) said he sees the pumping also, but figures it's just part of the medium and so ignores it. I'm afraid he's right and that some kind of subsonic filter would be the only real solution.
So, live with it or build a filter. Lets see what the New Year brings. There may be a project in my future.
Bob |
FWIW, some speaker manufacturers build subsonic filters into their speaks as a way of tightening up the low end by filtering out low end frequencies that the speaks are not designed to reproduce accurately. That is another possible reason why some do not observe this phenomena on their system. It is a true statement though that it is inherent to the medium. For example, I believe Ohm does this with newer design speakers that employ their "sub bass activator" circuit internally. |
Mapman...A passive rumble filter would require large and expensive inductors and capacitors. And lots of them to yield the minimal 18 dB slope. Rumble filters are only practical for line level signals. |
Eldartford,
I've seen the Ohm sub bass activator device. It is a rectangular circuit board just a few inches in dimension that connects between crossover and woofer internally as I recall. I ordered a pair and installed them into my Ohm L's as an upgrade. The cost was nominal as I recall, less than $100.
My understanding is that it acts as a subsonic high pass filter to some extent. It definitely helped clean up and tighten the low end on these moderate sized bookshelf speakers.
Here;s the description of the SBA upgrade on the Ohm site:
"Tighter and deeper bass is heard with the addition of a SubBass Activator (SBA) and vent adapter. The SBA eliminates the drive below the speaker's natural response to reduce distortion and clean up the deep bass. The vent adapter tunes the cabinet to work with the SBA and new woofers for deeper bass response. " |
the filters mentioned here are only masks trying to cover up another more basic problem and will only cause other unintended consequences. if the problem occurs in no other sourse, it is the tt and/or it's set up. the "rumbling" or "pumping" is not, i repeat, not a part of the vinyl medium that we must live with! |
Greetings all, as I've mentioned early in this thread my DIY ESP P99 subsonic filter has worked superbly in removing practically all unwanted subsonic energy with a rapid and steep response below 18 Hz.
There have been no adverse effects on the remaining audio spectrum above 18 Hz and greater perceived available power due to the main amplifier no longer being required to reproduce all that unwanted subsonic rubbish below 18 Hz. Regards and Seasons Greetings! Fap. |
Koegz said, "the "rumbling" or "pumping" is not, i repeat, not a part of the vinyl medium that we must live with!"
I say that's true, only if your system is not able to reproduce it. Then you have nothing to worry about.
Bob |
acoustat6 in your post i am not sure what you were suggesting? but if it was that my system was no "able to reproduce" because it does not meet your high standards, well all i can say is thanks for the laugh. i only hope to some day meet your lofty standard. |
in 100% of the cases I've seen over the years where "rumbling" or "pumping" was a significant issue at play, the cause was a warped or poorly cut record.
Lets face it, even if our turntables and systems are darn near perfect, few if any records are. Some are real bad. You'll hear the effects of a poorly manufactured record way before the stylus starts skipping grooves, especially with most good turntables that track very well.
If you are playing a record and getting a lot of pumping or rumbling visible with your speakers, just be glad that your table is such a good tracker and accept the fact that this is par for the course. Either that, or go for the filter if it is something that cannot be lived with. |
Hi Koegz, I was indeed suggesting that your system is not reproducing below 20hz and perhaps not even below 30hz.
Thats OK, no problem there, I am sure it sounds great!
Bob |
I do suspect some cartridges with higher compliance (stiffer) styli might be more naturally immune to picking up low end noise due to record warping or irregularities in the way the record grooves were cut (off center, etc.). |
Bob#2 - as much as I don't like to say it, because it might hurt some feelings and because we all know the size of our system reflects the size of our audio-manhood :-), I have to agree with you.
The subsonic problems I seem to have now were not there in the past. The resolution of my system has improved greatly with a better phono stage, better arm, teflon caps in my preamp, etc. Yes, the music got better, yes the sound is better, and yes I now seem to have a new problem caused by this increase in resolution.
Bob #1 |
Mapman,
You mean lower compliance... |
acoustat6 you must be reading a diferent post then i am. ptmconsulting posted a question based on his analog equipment with hiss tt and it's set up. also seeing that no normal human can hear below 20hz and that sound at that level is felt and he descibes the problem coming from his "speakers" and not sub. i own no vinyl music that i believe goes below 20hz. i do not listen to organ or classical music. although i listen last nite to stealy dan's "gaucho" and that could be definatly felt. l believe the rumbling he is descibing has to do with the tt set up, either in the bearing or platter or plinth with those steal screw feet and definitly is not something inherant in vinyl and that one has to settle for or mask. one of my first tt's had a similar problem. over a certain volume the tt would resinate. OH and my system sounds STELLAR, thank you very much! |
04rdking,
YEs, I got it backwards I think.
I did mean "stiffer" which I believe is in fact lower compliance. |
Hi Koegz, I am sure your system is capable of great sound, you will not get an argument from me there. And I assure you I am reading the same post.
I dont believe Bob#1s (ptmconsulting) issue is his tt, but the fact that he is able to reproduce these unwanted freq, whether they are subsonic (ie not heard) or rumble (pumping and audible due to its freq).
Whether this is due to his ablity to reproduce below 20hz (subsonic) at a significant spl level, or if it is from 20hz up (rumble) and his systems ability to play down to 20hz. Most assuredly both, but I dont know I am not there.
It could be a bass peak in his room which is accentuating his "rumble" problem at perhaps over a certain freq, say if he has a broad 10db peak over from 30 to 50hz.
Conversly it could be someones system is not able to reproduce 20hz and below for subsonics to be a problem. Or his system is not able to reproduce 20-40hz where rumble generally resides. As well as it could be that someone have a 10db bass null over the range of 30-50hz which is preventing them from hearing the offending rumble.
It could be that he has a very good in room response that is allowing his system to reproduce all of the noise produced on the LPs. Just as well as someone else may have a falling respose over the range that all of these problems occur at. Ie; a falling response from 50hz down, which is not at all that uncommon.
I too don't own any LPs that have music below 20hz, but all LPs do have noise below this freq, it is a systems ability to reproduce these freq which is the "problem".
You are pretty much correct that you "don't hear" these freq. Especially if you your system is not able to play that "low" or if your system can do 20hz and below, the question then becomes how loud do you listen.
I believe it has nothing to do with the type of music you listen to. Some LPs do have more subsonics than other LPs. As well as some LPs have rumble at a significant level as well. Some LPs have rumble that perhaps goes up to 30 or 40hz at a low level while others can have rumble that goes up to or even over 100hz at quite a high level, though that is rare. But is has nothing to do with the style of music.
Many of my LPs have close to zero rumble, or at least insignificant enough that it is not a problem. Though I always keep my rumble filter in at all times. Many of my LPs have rumble at a high enough level and freq, that it is an audible problem.
I believe that all LP systems would benefit from 20z (subsonic filtering). Regardless if your system is reproducing (audible) this sound or not. You do not even want your amps to be trying to reproduce this. And even a little bit in your speakers is not desirable. My 20hz filter must be kept in at all times.
I do not hear rumble on all LPs as well as Bob#1 does not hear rumble on all LPs. This sound is not coming from our tables, or we would hear it equally on all LPs when all of the LPs are played back at the same gain setting.
Your comment on the Groucho is nonsequiter to this discussion. Please tell me what you thought could be felt.
Bob |
"I believe that all LP systems would benefit from 20z (subsonic filtering)"
If done right, I would tend to agree. |
the kicking of the drum or the pluck of a base string can be felt as well as heard. my wife, who loves to say "i hear no diference" feels it as well. it is not a rumble but an extension of the sound. it is tight, well defined, inspiring and adds to the music. heard often in steely dan, van morrison and dire straits albums amongst others, it gives the feeling of being there. on a diferent point it is my understanding that sound under 20hz can not be heard by the naked human ear, but only felt. also with some changes to his tt the originator of this post claims to have solved his trouble. i do understand your point, just don't agree. i avoid placing anything between the source and speakers, other then the minimal required. i subscribe to the therory, less is more and try to seek it in my equipment(2 channel) set up. you seem to be more technical savy then i. notably i do not have agreat knowledge of 20hz-30khz, -3db or such, but i know what sounds good to me. i have a very mechanical type mind and see flaws in the physical makeup/desighn once i understand the workings such as in the tt in question. i do not wish to be argumenitive and insist i know all, i am certain i do not. it is just your solution goes against my listening belief that if something is off there is a reason and something is wrong in the chain and the repair is not by altering but to repair, adjust, get rid of or replace. i have a relitively large vinyl collection some are better recordings then other. it occurs to me that you probably have a sub, i do not know what your system consists of, i do not, and you are referring to sub rumble which i have heard caused by the sub trying to make sounds out side(above) it's capability. i do not use a sub because i do not like nor feel that they are true to the sound of the music, movies yes. they tend to over state or exagerate. but to each their own. |
It depends on whether what's happening below 20hz is related more to the music or noise. Best to eliminate the noise first if possible. |
I got some 180gm Acoustic Sound LP's for christmas. I have to say the subsonic pumping is almost gone with these. yes, there's still a little cone movement, but not like a regular flimsy record.
So the problem I'm having seems to be more record dependent than anything else, or I would have the same level or problem on all records, right? I still think it is a problem with the media and not isolation or airborne vibrations and stuff (because it happens when music is NOT playing also, in the lead in/out grooves).
In any case, it still sounds good and is not a huge issue. It's just my completest nature that I would want to remove it if I can do so easily.
Enjoy,
Bob |
Hi Bob, I agree, I too have some lps that have lots of low freq abberations (rumble and high levels of 20hz and below noise) and others I play are "close to perfect", very little rumble but the 20hz and down "noise" is there no matter what. This is the first thing you should address, as it does give your amp fits and also, even if you do not hear it it is screwing up your speakers sound trying to reproduce it.
Yes, if it is your setup it would be there regardless of the LP. You said subsonic pumping is almost gone with these LPs, what I believe you meant to say or are heaing is rumble (above 20hz). Correct me if you disagree. It can always sound better:)
My thought is that one can live with the rumble especially if ones system is down a a few DBs in the lower freq, but a 20hz filter will be of benefit to any system.
Bob |
I just received a pair of those 20hz FMOD RCA filters. Does it matter where I connect them into my system? My TT is connected directly into my pre amp. I'll post my results. |
Put them at the preamp output. They are intended to be used with a "line level" signal. Better yet, if your preamp has a TAPE interface, put them there with a short interconnect. Then you can easily compare with/without results. |
Ptmconsulting; i am confused, are you talking about cone movement on your sub or your speakers? |
There is cone movement on both. It is not audible on my speakers (which go down to about 30Hz I would guess, but due to the slope is probably still putting out into the 20's but at a lower level). The pumping on the subwoofer is noticeably greater and sometimes very audible. You can hear it by ear, like a whoomp-whoomp air pressure feeling.
I've tried several different methods of reducing resonance to see if that would improve things. Adding mass to the headshell, damping the tonearm, taking the table off the rack and putting it directly on the concrete floor, etc. There is no noticeable difference from any of them, so I think it is subsonics fromnt he record itself in my case. |
Hi Bob#1, you said, "It is not audible on my speakers (which go down to about 30Hz I would guess, but due to the slope is probably still putting out into the 20's but at a lower level). The pumping on the....
Not to be argumenative or anything, but when you said "it is not audible", do you think your speakers can move without making sound or using power from your amps.... just something to think about.
I do think you are going in the right direction:)
Bob#2 |
When I say it's not audible I mean the woofers are pumping but I don't hear any thumping in my ears, the way I do if the subwoofer is on. Yes, it is definitely being driven by the amp and using up some power but it doesn't audibly interfear with the music.
The sub has a substantially bigger driver which moves more air and is designed to pump out those low frequencies. I hear the "whump" from the sub.
So based on my experience with thicker records vs flimsy vinyl I definitely see less of a problem with the thicker records. So I am leaning toward the belief that it's on the records and my system is resolving enough to bring out the flaws in the medium. Again, this was not as much of an issue before I got a better phonostage.
All in all, again, turning off the sub seems to resolve the worst of this to my ears and, short of building a subsonic filter, is the solution I'm going with for now. None of the mechanical solutions I've tried seems to make any difference at all.
On another note, I have been playing with string recently in place of the rubber VPI belt and have noticed a nice improvement overall. Yes, I have a speed controller and it is essential to getting this right. No, it doesn't change the subsonic issues.
Happy New Year,
Bob |
disconect sub i agree. thickness of the vinyl, no way. i have some 2000 vinyl albums of all thicknesses and age. rarely does newer thick vinyl sound better then the original ussally thinner vinyl. there is little doubt in my mind that the main problem is your tt. i do not know where you live but bring me that vinyl and i will prove it. (voorhees nj) |
Just wondering ... the VPI platter is not supposed to be used with a record mat. It's design is intended to couple the record to the "vinyl like" composite platter.
What would a record mat do for me here? Might it help dampen these vibrations? What do they do for the sound (I would expect a dampening there as well, no)?
Any thoughts? Any recommendations on which ones to try? Anyone with practical experience using a mat on a VPI platter?
Thanks,
Bob |
There is no doubt that thinner vinyl is more susceptible to warping and that warped records will result in subsonic noise that can cause a subwoofer driver to pump wildly if transmitted and not filtered somehow. A cartridge with lower compliance stylus might be more immune to the problem, but the best solution is to replace the record with a better copy when this occurs (or get a good digital copy if not allergic to digital). |
Markpao said "I just received a pair of those 20hz FMOD RCA filters."
Did this help with your subsonic problem? Does it sound OK? Are you using them? Do you recommend them?
Bob |
Too bad that more phono preamp manufacturers don't provide an option for such a subsonic filter. Does anyone know of a high end phono pre that has this feature built in and is switchable? |
Stevecham,
Probably because it would raise costs and even perhaps make the product less appealing to high end purists who do not like any extra circuitry mucking with their signals.
I do find also that it is less of a real problem with many higher power modern amps these days that have the guts to be able to handle the low frequency noise in most cases (decent record pressings) without clipping so there is little audible effect and lower risk of causing damage to the speaks.
I mostly listen on my OHMs where the driver is contained within a metal mesh cage so I can only listen for subsonic issues, not see them. I have to go to my more conventional Dynaudios if I want to look for a pumping woofer. Practically, it has not been an issue worth worrying about for me. |
"Too bad that more phono preamp manufacturers don't provide an option for such a subsonic filter. Does anyone know of a high end phono pre that has this feature built in and is switchable?"
The Aqvox Phono 2CI |
Hello Acoustat6 and all,
First off let me make it clear that I do not have the experience that most others here have as I am a newbie making a re- entry into analog. Yes, I did receive the 20hz subsonic filters and installed them at my pre amp out. There was no question that the woofer pumping was reduced, but not gone. I also made a cartridge change to see if that would also help. I went from a Shelter 501MKII to a Clearaudio Concerto. The reason for the change was because there has been some talk that the Shelter is not a good match for my VPI JMW9 Signature arm and this could be part of the "woofer pumping" problem. So I went with something that worked better mathematically. I will say that I didn't see ANY change for the better or worse with this cartridge change. Maybe I should have left the calculator in my office? I hope this helps. |
Hi Markpao, you said "Yes, I did receive the 20hz subsonic filters and installed them at my pre amp out. There was no question that the woofer pumping was reduced, but not gone."
Dont forget that the 20hz filter will only reduce the freq below 20 hz at a rate as specified by the manufacturer (usually 18-24db per octave). It is not a sharp cutoff that will totally eliminate 20hz and below.
Also don't forget that you have not addressed the other side of this coin, rumble. Not turntable rumble, but record rumble.
Bob |
I don't know if anyone has suggested this yet, but try switching your system to Mono. If the preamp doesn't have a Mono switch, invest a couple of bucks in a Y-adapter interconnect at radio shack. If this cures your problem, as I suspect it will, you need a rumble filter that mixes channels below some frequency higher than 20 Hz. (The Y-adapter mixes at all frequencies). |
let's see, subsonic filter, rumble filter how about an air filter? to bright ad a tweeter filter. mids not right add a mid booster filter. how about, system sounds bad, get a better system. |
I was having the same woofer pumping problems with my Scoutmaster/Dyna 20X-H and tried a Speed mat. It did not help, nor did it (the mat) work with the ring clamp. What did help was a cartridge upgrade and proper cartridge alignment. It may have just been the alignment though- I did them both at the about same time. Some records still have the problem, though greatly diminished. |
