How to best isolate TT from vibration?


Hi all:

I'm currently using a Systemdek IIX table, which has a floating suspension system. I have it on a Atlantis Reference rack, but have replaced the top shelf with a 18" x 18" x 2" brick paver, and use (8) Vibrapod 4's under the table itself to prevent vibration. I still suffer from some skipping unless I walk ever so softly in my music room, most noticably at the beginning of an LP. I'm looking for input regarding what you fine members consider to be the best, but yet economical, methods of isolating this table and nixing this problem. Thanks,

Jim
musicseller
Gee....it didn't sound like that when it was in my head???
I've got to learn to read what I write!!???
You've heard it from Lolo, Nsgarch and Newbee.
I'm an architect and they all speak the truth....and yes.....if you can mount off a masonry wall, all the better!
Funny, when I first got my 'DEK after hard times forced an LP12 sale, I auditioned a vacuum-hold SOTA in a direct comparison. The 'DEK made music, the SOTA didn't: 1st class HIFI though. I use a chipboard plate and blobs of Sorbothane in place of the original feet. Not perfect, but far from the previous just tipeetoe and...! Oh, I got the Sorbothane from an Audioquest mat: another excellent HIFI/LOUSY music product!
I imagine so. I went with this because different numbers of pieces of MDF worked better with my Roksan Xerxes turntable, and originally the setup was on the floor. The best setup there was to have 5 layers of MDF on top and two layers on the bottom. When I changed to the SME 20/2A, it worked best on a wall stand with a single layer of MDF on top and bottom.

I started off using tennis balls, but they did not sound as good as the inflatable sports balls. I also tried bicycle tubes and a "sandbox" type of setup, but this is by far the most effective. The only drawback is that the balls need to be reinflated once or twice a year. Or you can just go buy a new set for $7.
Esox- this sounds (pun intended) like a diy version of the Gingko Cloud product.
Okay, this will sound goofy, but it will work.

Step 1 - Go to Home Depot and get them to cut you up a sheet of 1" thick MDF into appropriate sized rectangles. I use 15x18.5, which were the same size as my Target wall shelf. The number of pieces of MDF you use will depend on how you tune this thing later.

Step 2 - Go to the dollar store and buy your self a few packages of those little rubber inflated sportsballs (they look like soccer, basket, and baseballs). You'll need about a dozen (balls, not packages), maybe more depending on how heavy your table is.

Step 3 - Back to Home Depot! You will need 2" PVC plumbing fittings with a flanged end. Get some glue as well.

Step 4 - Glue the flange fittings to a piece of MDF in an even and logical pattern. Make sure you support the middle and the outside edges of the MDF.

Step 5 - With the flange fittings facing down, make an MDF/rubber ball sandwich. you can do this with the balls sitting on top of the flange fittings, and is is easier to assemble, but it sounds better for some reason with the flanges on top and the balls on the surface of the bottom piece of MDF. DO NOT GLUE THE BALLS IN PLACE!

Step 6 - Experiment with the number of pieces of MDF. You may find that more than one piece of MDF works better, or that 3 on top and 2 on the bottom work best, or whatever. Try to listen to each configuration for a couple of days before you switch. This will take a month or two, but if you are patient you will get it right.

This will only work if your table has a good levelling system, otherwise don't try it. Having said that, this setup cured some horrendous vibration problems in my room, and sounds good for very little money; $10-15 for balls, $25 for the MDF, $30-40 for the plumbing fittings.

No, I'm not on drugs.
a very good way to isolate hi fi gear is to make a shallow box out of mdf into which you place a bicycle inner tube (inflated) place another piece of 18mm mdf {cut to fit just within the box with the inner tube) on top, make sure everything is level and enjoy!

Since I suggested it, I tried the Ikea Lack side table with my AR turntable last night - similar three point suspension to a Linn. I have hardwood floors not carpeting, but I took some heavy steps in the room last night and the turntable tracked fine. The table was only $12.99 but the shipping was around $20, so if you have an Ikea near you it would be worth the drive. I have the table in dark brown and although it is cheaply made, it doesn't look too bad especially with a turntable on top.
I agree with wall mounting and also into a solid wall, preferably outside wall. I put mine in a partition wall, of necessity and the tonearm dances around when you walk past doh!!. Its still better than on a quality hifi rack, just choose your wall better than I did
I had this problem when I lived in an apartment in college and got my Linn. Linn recommended a Sound Organization table - light and rigid. (Being light and rigid, the natural frequency of the table is high and it is less prone to footfall.) Since I couldn't afford one at the time, Linn recommended a parsons table (sp?). These are those old low, square plastic tables with the four square legs that just push into the table. Many people used them outdoors. I finally got hold of one of them and the footfall problems were history. More recently, I have also heard that the Ikea Lack side table is now recommended by Linn and it costs $12. Since then, I managed to buy SO table and it works great..
if you have a 'flexible floor' and the tt is on a rack on that floor, you will not be able to eliminate the 'foot-fall' problem.....no matter what you do.....so you will have to live with that issue.

OTOH you can eliminate the other vibration causing problems (both air-born and floor music feedback as well as earth tremors) by using the same product electron microscopes use to eliminate vibrations......the Halcyonics vibration table. it makes all other vibration control systems look like toys.

unfortunately it costs around $8k.....but it does the job.

i have tried it. it is.......

the real deal
Thanks for all your input so far. Unfortunately there are some issues I cannot get around, or maybe don't choose to. I can't wall mount it, so that's out of the question. Vibrapod 1's or 2's don't support a TT this heavy and I don't want a Sota. In truth, switching from the standard top that goes with the Atlantis rack to the brick paver helped, as did the Vibrapod 4's; just not enough to make things worry-free. I may have to partially take the advice of Audiopath and "dump the Dek", but I'd just have to find a TT I like better. The XII, other than this quirk, is a fine sounding table and I'd hate to give it up if I can solve this annoying little problem. I had a Clearaudio Emotion, but sold that in relative haste because it was a pain in its own right, and I had a Nottingham Horizon that I used as a demo when I had my shop. I may go back to a Horizon. It was a good sounding, solid and very basic table. With the Incognito Option, or a totally different arm it may be worth reinvestigating. Thanks for all your input.
Yo Musicseller,

Dump the 'dek and buy a SOTA...then you can do jumping jacks in your living room while listening to the first track on your records.

Otherwise invest in a Bright Star AirMass isolation platform (www.brightstaraudio.com). You can build your own using an inner tube from a wheelbarrow tire and some plywood or MDF. By experimenting with the air pressure and mass (weight), you can tune out the 1-3 hz. resonant frequency of the floor.
After trying several changes to mass loading of platforms, mass loading of floor, isoltaors and etc. (some success but not SUCCESS). My final solution was 30 foot long interconnects to get the turntable in a more optimal location. Would have done the wall mount thing if I could have made it work with my room. You will find variance in opinion about whether long ic's between a phono amp and pre-amp are a great idea, but it is something that worked for me. Thanks to one of the agoners, I found an ic that I enjoy for US 200.00 ish so it is sort of economical.
If you don't WALL mount it ,you'll just be spinning your wheels. SYSTEMDEK XII MUST be wall mounted
Yeah I've noticed those 1-3Hz frequencies tend to rattle the house when magma seeps into my basement. Gotta get a lava detector.
Dear Jim: skipping when you walk in the room?

Maybe and just maybe the problem is not exactly a isolation one: I don't know which cartridge do you use and if the set-up is right and if the resonance frequency between the arm/cartridge is in the safe range. Do you already try with the higher manufacturer recomended VTF?

If everything is fine then the Jfrech advise is a best one. Stay away from Aurios or similar design devices for this kind of problem.

Regards and enjoy the music.
Raul.
Traffic, subways and other sources of Low Freq. Vibration (that shake the house) are included in my definition of "seismic vibration." The proof that wall mounting is not totally effective is to employ an isolation device under the component mounted on the wall. Even when the house is out in the country, away from the usual sources of vibration that plague city folk.

All frequencies of structural vibration will affect audio performance - especially the extremely low frequencies. Earth's crust motion (which is continuous and has a vibration peak in the range 1-3 Hz). It is a mistake to think that very low frequency vibrations, even in this 1-3 Hz range, do not have audible consequences.

GK, Machina Dynamica
Seismic vibration is at too low a frequency to be audible, and too low in amplitude to cause mistracking (unless you happen to be in an earthquake!)

If the problem is ground transmission of things like trucks, trains, or military ordinance (very) nearby, you'll be needing to soundproof/isolate the whole room, so the TT issue will take care of itself ;--)

Wall mounting is still the best solution.
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Unfortunately, (continuous) very low frequency seismic vibration forces the entire house or apt. to move up and down. Thus, wall mounting is only partially effective for isolating in the vertical direction - a "de-coupling" device is required to "de-couple" the audio component from the seismic vibration.

Note: My company specializes in vibration isolation.
I do agree w/ Newbee's exception: If you have a concrete slab-on-grade floor (or a 1 foot thick steel-reinforced floor in a hi-rise or loft,) then a stout rack (like a Billy Bags) spiked right into the floor will do it (or for the cost of a few concrete blocks and some mortar, you could build your own TT pedestal for pennies!

I also think unsuspended tables are the way of the future ;--)

I don't have Newbee's faith in jacking joisted floors. Which isn't to say that it can't work. It's just that a lot of the existing floor's construction details have to be just right.

Tips about wall shelves:

Mount them on any masonry wall, if it works out OK for you in that location.

Second choice, an outside wall -- heavier studs and thicker surfaces (more mass -- less vibes)

If you're in a new, cheap, tract house, on an inside partition wall -- don't despair. Wall shelves are usually 2 stud spaces wide (16" + 16" = 32") Get a 48" wide (4 ft) by 2ft high by 1" thick piece of Scandinavian plywood (the kind with many pretty laminations, like used in furniture), finish it natural or to match the wall and lag bolt it to four studs (16" + 16" + 16" = 48".) You can mount the TT shelf on the plywood panel with lag screws, but if you're really cool, you'll pre-install T-nuts on the back side of the panel to receive bolts thru the wallshelf after the panel is mounted to the wall. It'll look great and be stiff as a board (did I say that?)
.
Wall mount recommendations are right on.

FWIW foot fall induced vibrations are vertical and NO isolation system is going to eliminate them completely, not spring systems, nor isolation devices of any type. Believe it or not unsuspended tables acually deal better with foot fall problems than suspended ones. Think about it a bit and you will figure out why.

In addition to Nsgarch's suggestion, have you considered reinforcing the floor under your turntables rack. Assuming you're on the first floor, can you get under the house?
Wall-shelf. Target makes the Volkswagen of wall shelves --Available at Audio advisor, and other fine audio retailers ;--)
If you are interested, I am a distributor for the wonderful and extremely effective Aurios Pro-Max bearings.
Can get you a great price off retail.
IMO, your Vibrapods are much too hard. I am not familiar with your turntable but unless it weighs 128 lbs., 8 #4s is too much and they are doing you no good whatsoever.

I would suggest you try some #1 (maybe #2) and I bet that will solve your problem. This is how I eliminated the same kind of skipping in my Audio Aero Prima cdp. Vibrapods come in a range of softness for an extremely good reason!

Arthur
Assuming your on a 2nd floor or something similar?

Sometimes a Wall mounted shelf works best for foot fall induced skipping. Also, if there is any way to put a jack under the floor joists, directly under the table that can help. Not sure if you can attempt this one. One other idea is to move the rack to a different wall. Usually a outside wall is best, where the studs go down to the cement.

Just a few thoughts, others may have better/diff ideas...