Thanks for your reply Bob. I know that a lot of vinyl has rumble recorded (unintentionaly) into it. I have 3 copies of Pat Benatars' Crimes of Passion and they all have the same rumble. I keep toying with different ideas for filtering it out. |
Maybe your dyna, while still functioning fine varied from the spec'd compliance enough to cause the issue(?) I think all phonostages should have a subsonic filter, talking with a friend who mfg. tube gear, he expressed same sentiment. |
This solved the problem on all the LP's that I have played since I upgraded. There is still some little movement on my woofers, but not the "huffing" that I was getting before very audibly on my Rel subwoofer.
And believe me, I tried everything mechanical, short of an electronic filter, to identify the cause of this problem and remove it. It must have been a cartridge/tonearm mismatch.
Good luck |
Bob-
I am wondering, did this help with all you LP's, or just some. I know in my system I only have rumble on certain LP's. Also you say "I can now safely turn on my sub when I'm playing vinyl with no excessive pumping." Do you still have pumping?
Thanks for your insight- |
My rumble went away when I decided to change out my cartridge, which on paper looked to be a great fit with on resonance issues. I went from a Dynavector XX-1 HO to a Transfiguration Temper LO. I didn;t change anything else, but I can now safely turn on my sub when I'm playing vinyl with no excessive pumping.
Go figure.
Bob |
Nice thread. I stumbled upon it by accident. I'm posting since the last post is from April this year so I figure it's ok to keep it alive.
I'm with the camp that rumble/flutter/woofer pumping is part of the vinyl experience. If you don't experience it, then count yourself lucky. My setup is fine on paper but on certain records the woofer pumping was insane. It didn't seem to have much to do with record warps.
I think whether anything in the signal path causes a deterioration in transparency or affects sound quality is a moot point if your system is experiencing a rumble problem despite attempted mechanical fixes. The woofer pumping will have a much worse effect on the sound than a good quality filter that will relieve the amp from trying to reproduce LF signals that are not audible, and the woofers from unnecessary and stressful movement that with time will most likely cause damage. To me it's a silly argument to make. We're not talking theory, but practice; you're not listening on paper but with your ears and observe with your eyes.
For those who want a ready solution: get a KAB rumble filter. I got one, I'm in vinyl nirvana every time I listen to records, no woofer pumping, no distortion, no audible sound compromise; in fact, the sound has improved. |
I have bass cone movements every 30 seconds lasting for a few seconds. It is not really subsonic, but I think related to this topic anyway.
It is constant and audible with or without music playing but it only happens on the phono stage, not on the other inputs.
I have a Lyra Skala connected to a Lyra Erodion stepup and then an Audio Note M5 Phono.
The earthing is connected from the cartridge to the stepup and then continues to the AN M5 Phono.
The preamp sounds wonderful, but when the cone movements occur, it blends with the music resulting in clearly audible distorsion.
Do you have any idea what it may be or what I can do? |
Squishy balls didn't help. However, the balanced idea has merit, my new phono stage has balanced output so this may be a possibility.
DS |
..have you tried removing the squishy balls and tried the table solidly in place? ( Squishy balls never worked in my system) Also, a few years ago, if I had the grill cloths off, I could see the woofers slowly advance and contract rhythmically (probably not your issue) When I went to an all balanced system, the problem went away. |
I too have contemplated this problem. I get pumping woofers although I cannot hear any of the sound being produced, I figure it's too low to hear.
I haven't checked since I got a new phono stage but I am personally of the view that this is a problem with the records and maybe the resonant frequency.
The reason I think this is record and pressing related is that it varies greatly between records. I get it worst on an original pressing of The Joshua Tree. I'd be interested to hear what records others see this effect on.
Another aspect is the cart/arm combination. Using the cartridge database I work out that the resonant frequency of my combo would be 9Hz. Now my speakers are meant to have usable bass down to 8Hz - maybe it's just the resonant frequency being reproduced?
I have done extensive tests with isolating my TT. My TT sits close to the right hand speaker and there is nowhere else to put it. I have done extensive isolation and this helped the problem but did not remove the problem. I have done 2 experiments to try and determine if the woofer pumping is caused by insufficient isolation of the TT:
1) I bought a cheap 5 metre interconnect cable, put the TT in another room and still got the woofer pumping.
2) I have also done another experiment where you connect one channel of your CD player to the inputs you normally use for the TT, leave the other channel connected to the TT - then you place the needle in the groove of a record with the platter stationary and put on a CD. The idea is that the sound of the CD should not come through the speaker still sourced from the needle in a stationary groove of a record. I haven't tried this for a long time but the amount of sound which did come through was not even close to enough to pump woofers.
As a result of these experiments I did improve isolation with a sand box but I still live with some woofer pumping. I'll have to check out how much I get with the current set up. I'm not crazy about the woofer pumping but I am reticent to add a filter in the signal path. I would try one of the Elliot Sound products filters but have absolutely no ability in soldering, maybe one day I'll ask someone at work to show me or do the soldering for me.
DS |
|
hey acoustat6, i knowlonger own the 800d's. i have had duel subs before. no longer, not part of the REAL sound of music. ponder this bob, when you get a real two channel system, you can let us know! |
Hello Srwooten,
Just curious, what cartridge did you upgrade to? |
Koegz said, "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."
Hey koegz, no need to worry about a subsonic filter when your speakers (B&W 800D) are allready down -3db at 35hz and are -6db at 25 hz!! You allready have a built in subsonic filter.And rumble, just think how much less rumble (and music) you are missing when your speaker is incapable of much below 50hz.
Ponder that for a moment and when you get full range capable speakers let us know.
Bob |
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. |
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 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). |
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 |
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. |
"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 |
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? |
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 |
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). |
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 |
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) |
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 |
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 |
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. |
Ptmconsulting; i am confused, are you talking about cone movement on your sub or your speakers? |
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. |
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. |
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 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 |
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. |
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. |
"I believe that all LP systems would benefit from 20z (subsonic filtering)"
If done right, I would tend to agree. |
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 |
04rdking,
YEs, I got it backwards I think.
I did mean "stiffer" which I believe is in fact 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! |
Mapman,
You mean lower compliance... |
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 |
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.). |
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 |
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. |
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. |
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 |
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. |
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! |
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. " |
