Go buy Solid-Tech Feet of Silence. Solved the same problem. The turntable is actually suspended in air. I also used a 3/4 in thick cutting board to rest TT on and then placed the feet of silence at the 4 corners of the cutting board for stability. Ingenious design
How to isolate turntable from footstep shake or vibration
Even while the Oracle turnable that I use has a built-in springs suspension by design there is a low or even sub-low frequency boom every time someone walks in a room. This becomes really bad with the subwoofer’s volume set high as the low frequency footsteps make straight to subwoofer where they are amplified shaking everything around. It seems the cartridge is picking up the footsteps very efficiently as even a lightest foot down becomes audioable. What can be done to attempt to isolate the turntable from the low frequency vibrations? Interesting, that the lower the volume of the subwoofer, the less the footstep shake is evident and with the subwoofer turned off it is a barely a problem at all.
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@cleeds, certainly an old Sota is not going to be the quietest turntable around but a record is at least one order of magnitude noisier than that old Sota. My new one, which will hopefully show up next month is as quiet as it gets. I use a calibrated mic to "listen" to my system all the time. It's program has an oscilloscope function and I can plot a frequency response curve which for this purpose needs to be near field. Rumble is a constant. Record noise is not. It is also much louder than rumble. But, you do not even have to measure it. You can see it in the subwoofers excursions. To be short, there is plenty of noise between 3 and 12 Hz. With a flat record it is true that between 0 and 12 Hz is relatively quiet. Relatively. It is also true that a sub sonic filter will be useful particularly for the idler wheel drive people. For people like me who use subwoofers boosted to realistic levels subsonic filters are essential for vinyl users unless you never listen over 75 dB. Also if you do not want to rocket your subwoofer drivers into the next county a mute switch is a nice addition. |
I don’t use powerful subwoofers. I use a full-range speaker system that is essentially flat in-room to below 20 hZ. No sub here too, don’t know why people use sub at home for vinyl listening, and what is the speakers if they can’t reproduce bass? Sub is for cinema (digital) or as a competition for small bookshelf speakers that can’t reproduce bass at all. I’m with Tannoy System 15 mkII , don’t need any sub and life is good. |
Thank you for all your suggestions! I’ve double checked the suspension. And it appeared that the right tonearm side needed a stiffer spring as the aluminum housing was so low that it touched the base. It was simply sitting on the turnable instead of "floating in air". I have replaced the spring with the stiffer one and viola! The effect was instant. The footsteps rattle is gone. Even with the maximum subwoofer volume it is dead silent. It doesn’t even respond to me jumping in a room or shutting the door. It feels like I’ve got a free upgrade as it appears it sounds better! |
mijostyn ... Unfiltered the subwoofers will gladly try to reproduce this. They are not projecting any "sound" into the room. They are no where near large enough to produce those frequencies but, if there is an electrical signal at 8 Hz they will gladly flap around at 8 Hz adding distortion to the sound you want to hear ...I can assure you that your LPs have no electrical signal at 8 hZ. You obviously have a rumble issue and use essentially a rumble filter to resolve it. That works! |
@cleeds, not a tone arm resonance problem at all. It is set perfectly at 8 Hz (horizontal. vertical is a little higher 9-10 Hz.) The cartridge is reading irregularities in the records surface. No record is absolutely flat. Unfiltered the subwoofers will gladly try to reproduce this. They are not projecting any "sound" into the room. They are no where near large enough to produce those frequencies but, if there is an electrical signal at 8 Hz they will gladly flap around at 8 Hz adding distortion to the sound you want to hear. In my case each subwoofer has 1800 Class AB watts behind it that will amplify right down to DC. Filtering all this garbage below 18 Hz cleans up the signal very audibly. You would have absolutely no problem hearing it. |
mijostyn @cleeds , that is right, flat to 20 hz at 1 meter. There is no full range loudspeaker I know of capable of reproducing the bottom two octaves in your average room at realistic levels ...You obviously never heard an Infinity IRS Beta system. Essentially flat in my room to below 20 hZ. No Band-Aid "rumble filter" or heroic digital DSP required. |
@cleeds , that is right, flat to 20 hz at 1 meter. There is no full range loudspeaker I know of capable of reproducing the bottom two octaves in your average room at realistic levels. You have to be able to have separate control of that part of the spectrum. Your average room requires at least two 15" or four 12" subwoofer drivers to do the job. Room control and a lot of power help. To get the sensations of a live performance you have to be able to boost the low end 5 to 10 dB sloping up from 100 Hz to 18 Hz. Smaller drivers have to take overly long excursions to do this and distortion levels are much higher. At any rate, adding a bad subwoofer system is worse than no subwoofer at all so I can understand why many people do not. |
@esputnix, If you check with Oracle you will see where they have added a damping system to their sprung suspension - Parts & Upgrades | oracle (oracle-audio.com) MkVI Micro Vibration Stabilizer System (MVSS) upgrade; its a significant modification. What is likely happening is that the sub-woofer and foot-fall frequencies are exciting a table spring resonance. At resonance, an undamped system - in this case your floor - can amplify the vibration/displacement many times - often well over 20 dB. So, every foot step causes the floor to effectively bounce causing the stand to bounce with it and the undamped table springs really bounce. As has been suggested: -a rumble/subsonic filter 'may' help because it may isolate the frequency that the subwoofer is producing that is exciting the floor from foot fall; example Line Level Crossovers (hlabs.com). There are pro/cons to these, but they are cheap and there are other types available - just search. -modifying the table for the Oracle MVSS 'may' help because it now adds damping to the Oracle suspension that it currently does not have. If it does not fix the problem, it may still benefit the table once the subwoofer/foot-fall/floor issue is resolved - but this is a significant mod that requires machining the base. -mounting the table on the wall 'will' work; it isolates the table from the floor. -adding a large mass under the table 'may' work. -adding subwoofer isolation feet or pad 'may' work because it may isolate the subwoofer from the floor enough so that the resonance is reduced or eliminated (shifts/isolates the problem frequency enough); and these are not expensive. Examples are Amazon.com: SVS SoundPath Subwoofer Isolation System, 4-Pack: Home Audio & Theater; Amazon.com: IsoAcoustics Iso-200Sub Subwoofer Isolation Stand (Single) (New Model): Electronics; Amazon.com: Auralex Acoustics SubDude-II Subwoofer Acoustic Isolation Platform, 1.75" x 15" x 15", v2: Musical Instruments. -as has been stated - adding secondary springs under the table, is not generally recommended. The phase relationship of the two spring systems can lead to very unpredictable results with resonances at different frequencies that can make the situation worse. Good Luck, |
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All this advice, all these springs, etc etc....way over thinking and too much work. Just put it on a dedicated wall shelf with a nice thick Butcher Block Acoustics slab for it to sit on, as I already advised. You could invite elephants into your home and your records will not skip a beat. Leave the design of the turtable alone! It is fine....isolate it, simple. |
"The most cost effective answer will be if the Oracle feet can be replaced with Townshend Pods." I disagree---that still amounts to adding springs to a turntable with a spring suspension. And that is why I above suggested using a set of the Townshend Seismic Pods, not under the Oracle’s base (the non-floating frame which provides the table’s structure), but in place of the table’s stock suspension springs. Remove the Oracle’s springs, and install a set of three or four Pods under the floating sub-chassis---the bottom of each Pod resting on the shelf the table sits on, the top of each Pod in direct contact with the underside of the acrylic floating sub-chassis. That will isolate the sub-chassis from not only the shelf the table sits on, but also the table’s structural frame and it’s dustcover, as well as it's motor. In that regard, the Pods will provide an improvement in the sound of your table in general. The Townshend Seismic Pods may be used thusly with any number of spring suspension tables; I have done exactly that with my VPI HW-19 Mk.5 (a Mk.4 with it’s stock platter and main bearing replaced with that from a TNT-5). |
You got that one right, there are an awful lot of factors that go into it, which is why I lean so heavily on educating on principles first and recommending specific solutions second. If I was there in person it would be pretty easy to eyeball and come up with a solution. Over email we have to fall back on generalities. Mass will solve most problems, if you can get enough of it. That's the trick. Fortunately mass is dirt cheap. Literally: one or two 50 lb bags of play sand, in a box several inches deep, put a piece of MDF or butcher block on top, you are pretty much golden. Put some Pods on top of that, turntable on Pods, now you definitely are golden. You are doing it just like I did, Nobsound first as proof of concept, which then either is deemed "good enough" and you are done, or you like it and want more in which case Pods. If you do go to Pods remember Nobsound will work under all your other components, and you can make extra footers from the leftover springs. One of the all time great bargain tweaks. |
My turntable is neither shelf wall mounted or resting on a bedrock type of base. My table is an older one with no built in springs or other dampening devices. My house is over 100 years old, second floor, and moves slightly with season changes. I use multiple subs. Never have experienced a degradation in sound with these conditions but wondered if better isolation from vibrations would produce any improvement and, if so, would I notice it? In one of my previous posts I asked what could be done to isolate the table from unwanted vibrations. Thanks to millercarbon for his input. He recommended springs under the table. So, I ordered some Nobsound springs (since they're not very expensive). Even though I don't have any romping kids stomping on the floor I did notice a slight improvement in sound. MC also recommended Townshend pods which do the job even better but given their expense I decided to, at least, try the Nobsound first. So many factors in vibration control. Good luck in your quest. |
At AXPONA I visited Butcher Block Acoustics. Very nice turntable platforms. But I may be incorrect here, but I am not certain there is a substantial difference between them and one of the thickest maple cutting boards you can find on eBay for a lot less. So I put my VPI Prime Signature on top of one of those thick maple cutting boards. Never an issue. Done. |
As others have stated, adding springs under a table having a spring suspension is a very bad idea (imagine a car having two sets of springs for each wheel!)They’re called helper springs. https://www.tarett.com/items/996-997-991-products/996-997-991-suspension/996-997-991-shocks~springs/... One way to consider going is to install Townshend Seismic Pods under not the base of the Oracle, but in place of the stock springs, with the Pods resting on the shelf, not the Oracle’s base. Good idea. Which is why I said: The most cost-effective answer will be if the Oracle feet can be replaced with Townshend Pods. |
The resonant frequency of the system needs to be lower than the operating frequency for isolation to occur. Most isolation systems have a resonant frequency in the audio range. The only systems I know of, which are also non-powered, which the resonant frequency is below audio frequencies are all based on the "Minus K" platform. Most "Minus K" platforms are under 4hz resonant frequency. |
@esputnix: Is your Oracle the Delphi model? If so, does it have the Brooks Berdan mod? Brooks was an expert at turntable suspensions, bringing with him to hi-fi the knowledge he had acquired working in the field of race car design. He was an Oracle dealer in the 1980’s, and realized the mass of the Delphi’s floating sub-chassis was not evenly distributed around the bearing. As a result of that mass imbalance, when the sub-chassis was pushed down upon and then let free, the s-c would not rebound straight up and down, but would instead cant to one side and then the other. He devised a simple solution to the problem: add a certain amount of mass (in the form of a thick disc of stainless steel) at a specific location on the underside of the sub-chassis. With the added mass, the sub-chassis behaved in a perfectly pistonic manner. Brooks’ mod was written up in TAS (I believe), and lots of Delphi owners sent their tables to Brooks to have the mod installed. Brooks is no longer with us, but his son Brian is (his shop in Pasadena, California is named Audio Elements), and he may still be offering his Dad’s mod. Oracle themselves eventually incorporated Brooks’ mod into the Delphi. As others have stated, adding springs under a table having a spring suspension is a very bad idea (imagine a car having two sets of springs for each wheel!), even the superior Seismic Pod from Townshend Audio. Years ago Townshend made his Seismic Sink isolation platforms using an internal inner tube as the means of creating isolation, but I don’t know if their use was approved of for tables with spring suspensions. Max Townshend incorporated the Seismic Sink into the Mk.3 incarnation of his Rock turntable, the Seismic Pod into the Mk.7 version. One way to consider going is to install Townshend Seismic Pods under not the base of the Oracle, but in place of the stock springs, with the Pods resting on the shelf, not the Oracle’s base. Will that solve your footfall problem? I don’t know. Shoot Max T an email. Putting a table on a wall-mounted shelf has for years been the most commonly employed solution to your problem, an "outer" wall if at all possible. Another possibility is installing a set of "roller bearings" under the Oracle’s base. That design is a ball bearing sitting in a shallow "cup" (made of aluminum), and is available from a couple of companies (most famously Symposium Acoustics). Roller bearings provide isolation in the lateral plane, but zero in the vertical. Some people have used roller bearings in conjunction with inner-tube type isolators, with great success. |
Matter of fact that is exactly what I recommend doing, putting the spring suspended table here on top of a Townshend Podium or Platform. Don't know which Oracle we're talking about here and I'm not familiar with their suspensions either. But all we really need to know is the one we have here isn't isolating from people walking around. A Podium definitely will accomplish that. The only real questions are how bad does the OP want to eliminate this, and what is he willing to do? A massive rack like mine will just about do it, and it is very inexpensive to make. But it is incredibly massive (well over 500lbs) and a time consuming DIY project. Townshend Podiums will definitely do it, and improve all aspects of sound quality as well, but does cost a lot more especially as it will have to be pretty big, those Oracle have a big footprint! The most cost-effective answer will be if the Oracle feet can be replaced with Pods. Some turntables like Basis this is easy and the way to go. But Oracle half the turntable is about how it looks, so I don't know..... |
MC, You might be correct about the cause of the bridge collapse. I mentioned it more for the sake of humor than anything else, and my guess is or was that the resonant frequency of the bridge suspension(s) and the wind velocity had something to do with it. But I certainly did not back up my remark by actually researching the cause. If you look at the famous video of the bridge shaking itself to death, it appears that the suspensions, one on each side of the bridge expanse, are resonating at different frequencies, which causes the road bed to be twisting and tilting so crazily, which eventually led to disaster. I dunno. Anyway, we all agree that putting a turntable with a built in spring suspension on top of a spring-suspended shelf is usually not a good idea, unless the doer has a good understanding of the physics and the proper instruments to determine what might work. This is not a knock on spring suspensions per se. |
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After checking the suspension you should try a Wall shelf made for the TT. Like this Pro-Ject Wallmount it 1 Turntable Shelf-Audio Advisor This helps to eliminate foot falls since it is mounted to the wall instead of sitting on the floor. Another way with suspended tables is to hang it from the ceiling. This takes some knowhow to do but is very doable if you know how to find the ceiling joists. I used this back in the 70’s & 80’s with great success.. |
mijostyn @cleeds , you obviously have no experience with powerful subwoofers and turntables ...You’re half-right - I don’t use powerful subwoofers. I use a full-range speaker system that is essentially flat in-room to below 20 hZ. The problem is not the turntable. It could not be happier. The problem is the subwoofers trying to reproduce every little irregularity on the record causing the woofers to make long excursions. If I turn the volume up loud enough I can get the voice coils to hit their stops making a very painful sound.That sure sounds like a problem to me. I want my woofers to reproduce what’s on the LP, unfiltered. If you’re getting "irregularities" that cause "long excursions," then it sounds like you have arm/cartridge resonance problems. Those can usually be resolved without relying on rumble filter Band-Aids but - as I said - rumble filters do work. It’s fine if you like them. |
@cleeds , you obviously have no experience with powerful subwoofers and turntables. Sub sonic filters are not Band-Aids. A sub sonic filter is essential if you are using a turntable with powerful subwoofers. I can play records without the filter all the way up to 85 to 90 dB before there is a noticeable degradation in sound quality. This is with the old Sota Sapphire and Syrinx PU 3 tonearm. It is not feedback, it is distortion. If I turn the filter on the distortion disappears. This is with a digital filter not an analog one. The problem is not the turntable. It could not be happier. The problem is the subwoofers trying to reproduce every little irregularity on the record causing the woofers to make long excursions. If I turn the volume up loud enough I can get the voice coils to hit their stops making a very painful sound. Since the signal has already been digitized creating a subsonic filter takes just a little programming. It does not add any distortion or phase shift unlike an analog filter. |
The Tacoma Narrows bridge collapsed twice. Neither time due to being suspended. Both times due to wind vortex. Wind blowing through the Narrows creates a low pressure on one side, causing the bridge to first vibrate up and down and then twist slightly. The twist creates low pressure on the other side. The twisting of the bridge increases until failure. https://www.youtube.com/watch?v=OrqdFxpM_N4 If you go looking for answers to problems it helps to find those who actually have the answers. In cases like this they tend to be engineers. Springs do work great, you got a good tip to go read the turntable spring thread. Springs however have the problem of resonance. Without damping they can sometimes create as many problems as they solve. A lot of things are like that. See for example all the ideas above. So springs are a big part of the answer. But they need to be damped. The trick is to engineer just the right amount of damping. Townshend Pods are designed to do exactly that. My rack is on a suspended wood floor. It is massive, because mass itself is one means of controlling vibration. Mine uses a combination of concrete, sand, and granite, with carbon fiber. But even this is not enough. Springs were a big improvement, and Townshend Pods the best improvement of all. What exactly will be best in your particular situation depends a lot on your particular situation. I can tell you though you can stomp around all you want in my room the woofers move only to the music. There are many possible solutions to your problem. They all start with first understanding exactly what the problem really is: vibration control. Pods are the easy fix. But there is a lot more you can do to go even beyond that, if you want. https://systems.audiogon.com/systems/8367 |
At any rate Lewm is correct. Putting a suspended turntable on springs will probably have an adverse affect. The problem here is the Oracle's springs are not isolating the sub chassis from footfall. Either because they are tuned to the wrong frequency or they are poorly dampened and unstable. The only solution other than changing turntables would be a wall shelf if the wall does not shake. |
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Usually it’s a very bad idea to “suspend” on springs a turntable that already has a built in suspension. So I am surprised that a few recommended adding a sprung shelf. The two suspensions will inevitably fight each other which could end up with positive feedback of vibration. Remember the Verrazano Narrows bridge collapse. |
mijostyn ... It means that vibration is getting to the sub chassis in spite of the suspension either through a poorly designed suspension or directly vibrating the sub chassis ...Not necessarily. If this is an Oracle Delphi (the OP doesn't say what model Oracle he has), then setup is even more critical than with many turntables. Its springs need to be individually rotated within the suspension towers so that the entire suspension functions pistonically. It is a very tricky adjustment to get right and it also drifts over time, requiring readjustment. It's a nuisance - and part of why I sold my Delphi way back when - and the table won't perform well if it's not properly setup. It is very important to use a subsonic filter and digital filtering is the only way you can do this effectively without injuring the bass. I roll off at 18 Hz 80 dB/oct. I use a Sota and a large subwoofer array and have absolutely no issues.Subsonic ("rumble") filters are a Band-Aid so if you use them you already know you have issues. They certainly can be effective, but I think the best solution is to remedy the problem at the source. It can be done - my system is essentially flat in-room to below 20 hZ. That's spooky bass with no rumble and no rumble filter. |
I do not use a suspended turntable but I have had successful isolation using an HRS platform (S level) and a Vibraplane. They both work well independently and even better together. Obviously, I would try some simple footers first as you could end up spending more on isolation than on the turntable itself. |
That is disappointing. It means that vibration is getting to the sub chassis in spite of the suspension either through a poorly designed suspension or directly vibrating the sub chassis. You can try damping the suspension by stuffing some foam in the springs. Later versions of the Oracle add adjustable damping. Subwoofers are a huge problem for turntables especially if you have them set where they should be. The low frequencies will fibrate the tonearm directly through the air. It is very important to use a subsonic filter and digital filtering is the only way you can do this effectively without injuring the bass. I roll off at 18 Hz 80 dB/oct. I use a Sota and a large subwoofer array and have absolutely no issues. The turntable is however on a very heavy cabinet on a concrete sub floor. I have used the Sota on several wood floors over the years without any difficulty and have seen SME's and Basis tables do the same. Adding mass under the table usually does not help. The floor just bounces at a different frequency. There is a chance that the problem is not vertical vibration but lateral vibration in which case using a sturdier rack and damping the springs will help. You still should look into a subsonic filter. |
