Springs under turntable

noromance, you need to look at the Solid Tech Rack of Silence 1 Reference. It will handle 40 kg https://www.solid-tech.net/silence/?SingleProduct=28

Loose marbles roll west.

Never been. Just knock off the “e” as in back side:)

Lewm, exactly right. The springs have to have the exact same rate and they have to be located exactly the same distance from the center of mass. Unfortunately, this is not so easy to find without harming the turntable. The result is that is is extremely difficult to get this right at a frequency below 3 Hz. It is far easier to create an unstable system than a stable one. INHO if you want a suspended turntable, and I believe everyone does even if they don't know it, buy a well engineered suspended turntable or a MinusK platform. This of course eliminates the Linn LP12:)

Yes Uberwaltz, you are right but the resonance frequency of the suspended units is so low. In Boston after the Big Dig a concrete paneled ceiling in one of the tunnels broke and collapsed on a car killing I think it was two people. Traffic though the tunnel created very low frequency rumble exciting the panels cracking them.
Again, they are so heavy there is not near enough energy produced by even the largest system to get the concrete "ringing"
That would apply to apartment buildings, office buildings and skyscrapers. Not to mention you can't play a system very loud in those buildings without pissing someone off.
Most of us I would assume (maybe I'm wrong) have reinforced concrete slabs sitting on compressed stone dust, a wonderful floor for a Media room. 

Obviously cleeds. But out of level a tonearm will add additional skating forces one way or the other and yes in an ideal world all parts of the turntable should operate in exactly the same plane. It is just a good measure to put the bubble next to the part that matters the most. And you are dead wrong cleeds. Unless you are using an arm that is dead straight raising and lowering the arm will change the azimuth, within the arc where the arm is expected to operate it is very slight but it will change by a minute or two.

I made a big mistake. It is not a resonance frequency I was talking about above but the energy or power required to move the concrete. If you could pluck the cables holding up those concrete slabs the frequency would be very high because the cables are stretched tight and they are not very long. In buildings I believe the concrete is going to be placed on steel girders. The resonance frequency of the floor would be determined by the weight of the floors and the flex of the steel girders. The only thing I could hear when I lived in a 19 story apartment building was a low frequency boom when someone upstarts jumped down on the floor. A person weighting around 150 lb is going to put way more energy into the floor than any HiFi could. I had RH Labs subwoofers at the time and the only complainers were my next door neighbors. Nobody up or down ever complained.

twoleftears, 800 volts and 250 amps and you should be in great shape.

Lewm, you and none of those other people obviously have not heard a system like this. I would love to have you over for a quick demonstration and don't forget I am a fellow ESL lover. I am talking everything from Beethoven's early string quartets to Nine Inch Nails. If you think your system images now, I can make it image a lot better. If you think you have decent bass now, I can make Ron Carter materialize in your listening room. Any system you have heard was either set up incorrectly or it was using a sub standard unit without the necessary processing speed or resolution.  

indranilsen, 3 Hz is slow enough you can just count. In poorly dampened systems the turntable will keep bouncing for a while. If it does not bounce that would mean the frequency is way too high.

UBERWALTZ, that was not at all what I was saying!!! I was saying a proper DSP system. I was not reflecting at all on anyone else system in any way shape or form so please calm down.

Nice work Indranilsen, That is about as far as the Sota springs will compress before the chassis hits its stop. Remember the Sota subchassis hangs from its springs. This is the best picture I could find of it
https://hometheaterhifi.com/reviews/vinyl/turntables/sota-nova-turntable/.
If you hung a platform with springs you could put your turntable on it. If the springs themselves were hung from a threaded rod you could adjust them for turntable level and any mass configuration of the turntable.

@mitch2 , you are exactly correct. Low bass pushes the suspension into it's nonlinear zone. Then there is doppler distortion on top. 
If you have at least two subwoofers of high quality you can push the high pass filter up as high as 150 Hz. Imagine doing that to K horns. JEEZ!

Lewm, not at all but, people do funny things. Reducing the spring rate would be tough. You would have to replace all four springs with springs exactly the same size and length under tension. Some people may have added damping to the springs by stuffing them with foam. If you look at the link in my last post in the middle of that article is a plexiglass model of a Sota. The springs are hung from the top plate. Shims would just lower the sub chassis dropping the plater and tonearm relative to the motor.

Anyway, my resonance frequency is low enough that I can count it. With a record on it will take 7 bounces before it stops and I would have to say that it takes about 2 seconds but I have not tried to time it accurately. The idea is to get it below record warp frequency so they do not interact. Tonearm above, turntable below. I can play a severely warped record without difficulty.

The Sota's are not easy turntables to take apart and I would not want to risk damaging the wooden plinth.  IMHE the suspensions are tuned just fine as nothing in a normal environment bothers them. I have never felt the need to take one apart which is unusual for a guy who took his Divas apart to install new ribbons. 

Delmonte? During WW2 my deceased uncle made a fortune packing fruit which he sold to the military. That company was called the East Indies Fruit Packing Company. You know that company now as Delmonte. In the late 60's my uncle retired from his position as CEO and handed the Baton to his nephew, the nastiest SOB I have ever met. I banned Delmonte products until he passed. They do have the best Pineapples. In the mean while my uncle took his fortune and opened up Flagler Dog Track in Miami, FL and made another fortune. He gave at least 75% of it away mostly to educational institutions and Israel. In 1974 he started getting chest pains. His cardiologist begged him to go to the hospital. Instead,  he flew to LA for a meeting. At the end of the meeting he stood up and died on the spot. Age 60. I would think the spring rate of a Delmonte mandarin orange can would be just a little high:)

Good noromance. Just don't sneeze:) Lewm is absolutely correct. For a driver to do its job correctly it has to be held rigidly in space. Any spurious vibration of the driver is distortion. The problem really does not become critical until you get down in the bass frequencies. There are several ways of dealing with this. First would be making the cabinet very heavy and stiff. Second would be spiking the cabinet to a very solid floor and third would be using counterforce design with the woofers. Best would be all three together. Putting springs or foam under loudspeakers is 180 degrees the wrong way to go. There is a huge difference in requirement for a device that is designed to pick up vibrations and a devise designed to produce them.

Lewm, You put a record on the turntable with any record weight type device you use then press the turntable down evenly to stretch or compress the springs equally then let go and count. 3 hz is very slow and should be fairly easy to count. If the turntable bounces so fast you can't count it then you need to use springs with a lower rate or add mass to the turntable.
When I hit my Sota with a hammer I am not hitting the suspended part of the turntable. That is inside the plinth. If I abruptly jerk the outside of the turntable (moving it say 1/4") the suspended section will start bouncing at 3 Hz. The tonearm will not skip. If I jerk it hard enough to bottom out the suspension in any direction then the tonearm will skip in a major way.

Mahgister, I have decided that there is absolutely no way to explain anything with you. You are an inexplicable force of nature. You are however entitled to do anything you want with your system even if it leaves several of us scratching our heads. You are certainly not alone in this regard. Millercarbon comes in a close second. You guys keep us on our toes:)

Bobby1945, in that situation the springs are not isolating the speakers or the floor from anything. It is a concrete floor. The speakers should be solidly on the floor with the midrange drivers at ear level by whatever means looks best to you. It is almost a purely cosmetic decision. 

The only thing a concrete floor does not isolate you from is an earthquake. None of our systems have enough power to move something as heavy and stiff as a concrete floor not to mention it is sitting on compacted stone dust. 
Millercarbon, glue an accelerometer to you garage floor and record its output while you start up your car, rev the engine and drive in and out. Please tell us what you get!
What I see here is a lot of wishful thinking without any science to back it up.  

Goners know I am a big fan of suspended turntables. I will never own anything else. There are two big issues. First, the resonance frequency has to be below 3 Hz both vertical and horizontal. If you get to close to the tonearm’s resonance frequency fun things will happen. Next, a mass placed on top of a spring is unstable. Not only will it bounce vertically but it will wobble side to side and if the mass is large enough it will fall right over. This tends to be the case when you get the resonance frequency low where it should be. When you hang a mass from a spring the pull of gravity always returns the mass to vertical, a much more stable situation. So, the best way to do this is too hang a platform from three or four springs and place the turntable on the platform. Or, you could buy a MinusK platform or you could buy a SOTA, SME or Dohmann turntable. Isolation is critical for turntables and a properly sprung turntable is much quieter and impervious to almost anything. You should be able to hammer on or kick your equipment stand and not hear a thing. All of the above tables will do this and if you are clever you can get the same results. You can dampen the springs by inserting foam rubber into them.

Noromance, If it is bouncing less than three times a second you are fine. You can use the same springs all round but you have to locate the center of mass and place them equidistant from that point unfortunately a tricky thing to do. If you use springs of unequal rates and they do not bounce at the same speed you can create an unstable situation. Correct, in this type of situation it is difficult to hand Q the record. This is one resaon the SOTA tables are so nice. The hung suspension is inside the plinth so you can put a hand down on it. you can even rap the plinth with a hammer no problem. Designs like the SME you have to use the Q device. 
If you think this sounds better you may want to consider a carefully engineered product like the MinusK stand or the SOTA turntable. 
Many of us know for a fact it sounds better including Michael Fremer who puts his $100K turntable on a MinusK stand. he designer of that turntable now has a MinusK stand built into his turntables!

rixthetrick, and on what science to you base this rather floral opinion on? 

"When correct implementation of zero stiffness on loudspeakers is administered, there is no question of the superiority of this engineering practice on the voicing of the loudspeaker." (rixthetrick)

rixthetrick, What is zero stiffness? That is a term I have never heard before. How is superior when it comes to "voicing" a loudspeaker. 

mambacfa, in the case of industrial machinery you are trying to isolate everything else from the vibrating machine. Listening to the machine vibrate is not the objective. I think that is quite different from a device that is intentionally either producing or reading vibration that has to be transferred in an accurate way. The reader has to be protected from all other vibration in the environment and the producer has to be locked in space so that it does not produce any unwanted vibration.

No Flatblackround. I think he is doing cocaine. That produces zero stiffness:)

Lets try to make things simple. Play something with a heavy bass line and put your hand on the speaker/subwoofer. Any vibration you feel is distortion. Ideally you should not feel a thing. If the floor resonates it will do so regardless if the speaker is spiked to it or floating above it on springs. In order to keep the speaker from transferring vibration to the floor the resonance frequency of the suspension would have to be below the lowest note the speakers are to reproduce which means below 20 Hz. Tap your speaker and they will bob for hours. Bring on the damping. Above that frequency the speaker is free to vibrate and add distortion.
Floors are very well fixed in all directions except up and down in the case of wood joist construction. The degree of stiffness varies so every floor has it's distinct resonance frequency. Speakers generally do not point up and down. This is a good reason to avoid down firing subwoofers. You are less likely to excite the floor's resonance frequency. In most cases you are going to be better off fixing the speaker to the floor even if you are not on slab. The best speakers are going to have a very stiff heavy enclosure. 

Uberwaltz, the 401 is a heavy turntable. To do this even close to right you have to find the center of mass of the table and place three or four springs equidistant from that point. Then you have to get the spring rate low enough to get you under the 3 Hz limit. At best the situation will be wobbly. You could put the springs in cylinders and add heavy oil for damping and the engineering continues. The more stable way to do this is to hang a solid platform with springs. Look carefully at the SME 30/12 turntable. You could replicate this situation without too much difficulty. 
If you are not into this degree of experimentation you probably should leave things as they are. The MinusK platform although expensive really is the best solution for unsuspended turntables. You just weigh your table and they will send you a platform with the right spring rate.

mwinkc, I have that record. Lots of fun. I think they stuck the microphone in the kettle drum, makes my windows rattle. 
Isolating any turntable from the environment is essential for the best playback. The springs act as a mechanical filter. All frequencies above the resonance frequency of the system will not get through to the turntable. All frequencies below will get through. This is why the recommended resonance frequency is below 3 Hz. If you have ever played with an AR turntable or the LP12 that is pretty wobbly if not done right. Both these turntables use exactly the same suspension design. It was a good start but there was substantial room for improvement. Sota made the first stable suspended table in 1980 or so then came Basis and SME. All these tables have chassis that are hung from springs instead of sitting on them. The Solid Tech Feet of Silence are the best aftermarket springs I have seen if your table is not too heavy. The feet are hung from their springs. They offer two spring rates and two different kits of either three or four feet. Any turntable that is not already suspended should benefit. 
The next evolution is suspension design is MinusK's negative stiffness design. It isolates down to 1 Hz remaining reasonably stable. 
It was designed for delicate lab gear like Scanning electron microscopes.
I find it interesting that lab gear that is totally electronic does not require isolation.

Yes Lewm, but they can not see Sh-t if the specimen is not held perfectly still, a mechanical issue.

Then I did not present it correctly, my fault. If I had an EM I would not let anybody near it either:)

Uberwaltz, you REALLY need a Schroder CB on your Avid. Your other turntables will become conversation pieces. It would be very expensive to make a better record playing device. With the different weight cartridge mounting plates you can put just about any cartridge on it. It is the most perfectly designed pivoted tonearm in existence. "Rank Amateur"? Surely you jest. 

rixthetrick, Whether or not vinyl sounds better than digital depends almost entirely on the way the music was mastered. An album mastered for digital is very hard to beat. But there are masters that sound better in their vinyl versions. I can only guess but I would say off hand it is about 50/50. Vinyl requires more effort, space and mechanical aptitude. If you like old sports cars you will love Vinyl. If you only drive Audi's stick with digital. 
If you have wood floors this is a very important thread. There are many audiophiles who have to walk around on tip toe while playing a record. Because of anti skate if the stylus loses contact with the groove the arm will skip backwards. In some houses this can happen with every step.
A turntable that is suspended correctly will not skip at all. Examples of properly suspended tables would be the Sota, SME, Basis, Dohmann and I believe the Avid Acutus. Sorry if I missed any. The Sota's certainly represent the best value. I can hit a Sota with a hammer and you will not hear it through the system. 
You can not believe the amount of noise and vibration that travels through a house. The term used was house rumble. The washing machine, various transformers, fans, plumbing, the truck traveling down your street.
A turntable is a very sensitive vibration measuring device. With a suspension tuned to 2 Hz the only vibration that will get through to the cartridge is you picking up the turntable and dropping it on the floor. 
This is only one aspect of turntable performance. As uberwaltz related, this is one very deep rabbit hole. Try starting a thread on Direct vs Belt drive and see what happens:)

Rix, a turntable suspension is just a simple mechanical filter. The trick is setting it up so it is stable. As for subwoofers the trick is to give the driver a perfectly solid enclosure with an infinite mass. Not so easy. Put your hand on your subwoofer enclosure while playing something bass heavy.
Any fibration you feel is distortion. That vibration is either from the enclosure walls moving or the entire subwoofer moving. In most cases it is both. Ideally you should feel nothing. You can not isolate a subwoofer from the house. Bass is insanely powerful. Put on a 30 Hz test tone and turn up the volume. Your entire house will sing at 30 Hz, glasses, plates, pictures, the walls, your teeth, everything. Fortunately for us our brains can only pay attention to the loudest noise. With music and the satellites running you can't hear it. If you don't want to hear your car rattle, turn up the radio. The medical term for this is "masking"
I had an older S5 V8 with a manual. It was hands down the prettiest car Audi ever made and a very satisfactory daily driver. 

If the resonance frequency of the sprung mass is higher than 20 hz the whole thing will vibrate at that frequency which will definitely do some interesting things to the bass. None of them good. The reason that you should set the springs below 3 hz is so you can't hear the suspension and anything that is happening in the room above 3 Hz. A good suspension should produce blacker backgrounds and isolate the turntable from foot falls and the kids hitting your equipment rack with a basketball. Otherwise it should do nothing to the sound. 

Indranilsen, exactly that is why you have to hang the mass from the springs vs placing the mass on the springs. This is what the Feet of Silence do and why they work so well. You ordered them just right for the lowest resonance Frequency and because of their design they are inherently stable. Great product. You can throw those Nobsound springs away. Bad design.
Rix, I build my own subs and have been through just about every permutation you can think of. Your opposing drivers (force cancelation) is a great way to go. But, as I said before it does not matter if you subs are spiked to the house or suspended. You can not keep the bass from getting to the house. Put on a 30 Hz test tone and walk around your house. Stuff in rooms on the far end of your house will be rattling. There is no way you can stop it all. IMHO spiking them to the floor is the best solution. Springing them will create a resonance peak unless you get the spring rate very high in which case you are doing nothing. You can not isolate your house from bass. 

Noromance, bad design for anything. If you could get them down to the right resonance frequency they would wobble all over the place. People were also discussing the use of springs under subwoofers and I expressed my opinion that it is not a good thing to do.

As far as Bass is concerned, everyone should have a pair of good head phones. Forget about the image but focus on the sound and detail. This is the bass you should hear out of your system ideally. Using a record with an acoustic bass solo to compare is ideal. If you like pushing the lower frequencies louder as a matter of taste well, that is up to you but you will sacrifice some detail. 

Indranilsen, You have to level the turntable with a record on the platter and yes it always matters. Perhaps not as much with a pivoted arm as with a tangential tracker but still. You may also want to adjust the feet so they all bounce together if you can. Lock the tonearm in it's rest. Push the turntable down stretching all the springs to their limit and let go. The springs that bounce fastest are farthest away from the center of mass so move them a little closer to the center of the turntable. Try to adjust them so that they all bounce together at the same rate. The games we children play. 

indranilson, you are certainly spending less than a MinuK platform which is no piece of cake to set up either. You have to move the turntable around on it to get it to balance right. Turntables never come with an arrow pointed at their center of mass.

There are racks like the Grand Prix Audio that isolate each shelf at a patently ridiculous price. IMHO, excepting the turntable, if you place all your equipment is separate enclosures isolating them from direct sound 
you are good to go. I do not like open racks. I prefer fully enclosed cabinets which are stiffer and easily damped. I do not put my equipment on display where it can collect dust. It is all hidden. Maybe I am just old fashioned 
 
The turntable being a vibration measurement device is another story. It has to be isolated from everything. I will never buy a turntable that is not suspended on an appropriate suspension.
The best thing to do is put your turntable in another room. Phono amps are now coming with balanced outputs that will make this much easier to do but most of us will not have that capability. 
The best way to shield the record, tonearm and cartridge from air born vibration is to cover the turntable during play, like putting ear muffs on.
My turntables have always sounded better with the dust cover down. The echo that you get with the dust cover up is an appealing euphoric distortion so, many are insistent that dust covers make things worse. Perhaps poorly designed ones do. But with my system people uniformly think it sounds better with the dust cover down.  

Mitch, if you hear a difference you are blessed. Set up your system any way you want. 

Millercarbon, I have done that experiment with a tube phono stage, an oscilloscope and a test record. There was no difference to either my ears or the oscilloscope trace at any frequency. As for my speakers? My subs weight 250 lb each and I have 4 of them. My speakers are 7"11" tall and my ceiling is 8" so putting anything under them is a non starter. The subs are so heavy and stiff that they do not vibrate. I have Vinyl and CD sets on display right on top of them.  Trying to isolate a subwoofer is beyond silliness. When bass is produced by a powerful system capable of going flat down to 18 Hz the entire house vibrates isolated or not. Put on a 30 Hz test tone and turn up the volume. If you have a decent system everything in the house will start buzzing. Any movement of the subwoofer itself creates distortion. Mine don't move because they are so heavy and they are spiked to the floor. The stuff on top of them doesn't even move including my Mo Fi Beatles set. But turn em up and the entire house buzzes. If you think you hear an improvement in your bass by putting your speakers on springs it is purely psychological or perhaps your speakers sound better just because they are up higher. So get yourself a nice looking set of speaker stands. But, subwoofers to perform their best need to be right on the floor up against a wall or in a corner. They gain up to 6 dB in efficiency this way and eliminate the first reflection entirely, improving bass throughout the room. 

Millercarbon, with all the neat improvements you have made you must have one heck of a system. 

Uberwaltz, you measure it!  Check out this https://www.parts-express.com/dayton-audio-omnimic-v2-acoustic-measurement-system--390-792. My room control system essentially does the same thing. It measures each individual speaker. The frequency response above 10 kHz is significantly different in my right ESL than in the Left one. The only difference is the right one has a window in front of it on the side wall. The system corrected it but beforehand the window was smearing the image.
To produce the best image the frequency response of both speakers has to be identical or the image will smear to the side that is louder at any given frequency. There are always differences from one speaker to another of the same type not to mention that the speakers occupy different positions in the room. If you measure your system you will be amazed if not terrified at the variations in frequency response particularly below 100 Hz. The curve will look like a profile of the alps. 
It is a lot of fun to measure other people's system and show them how bad things are. 

So, Uberwaltz, do not downplay those windows. More than likely they are having a significant effect on the sound. But, it is hard to predict how. If you want to know measure it. But if you are not planning to get a room control unit don't bother. Ignorance is bliss. 

Lewm, you have no idea what you are missing. The really good units like My TacT and the Trinnov Amethyst do all their processing at 192 hz 48 bit
It is totally transparent. The power of these units is amazing. You not only get automated room control ( they automatically generate filters that bring each speaker individually to flat) but an incredible subwoofer crossover and bass management. I can independently change the frequency and slope of either the high pass or low pass filter on the fly. I can use slopes up to 10th order. I have dynamic loudness compensation. It changes its corrective slopes automatically with volume. The balance between bass treble and mid range stays exactly the same regardless of volume. I can program filters to adjust frequency response any way I want with 0.5 Hz precision. I can delay individual speakers so the the sound from each hits your ears at exactly the same time. Using this capability I can put the sweet spot anywhere in the room! This capability also matches the subwoofers in phase and time to the satellites. I can hold 9 different frequency response curves in memory and I can switch back and forth on the fly. As an example one has the BBC or Gundry dip programmed in so if things get harsh I activate that curve. All the programming is done on a PC and all the filters and curves are displayed in graph form. Everything that this unit does is done without any distortion. It is invisible. 
Talking about unbelievable differences, if I switch the system to bypass my wife will even ask me what happened. 
Once you use something like this you never look back. Back is the stone age. If you think you do not need it get a calibrated microphone and measurement program and check your system out. 

indranilsen, The MinusK platform is not that hard to use. You move the turntable around on it until each corner of the platform compresses the same distance. It takes about 15 minutes to get it right. When you order the platform it is made for the specific weight of your turntable. You do not have to deal with spring rates at all. 
My feeling on the subject is straight forward. I will not use a turntable that is not isolated. I would rather buy a well engineered turntable, suspension built in than have to mess around with MinusK platforms and such. There are many excellent suspended turntables from the Sota Sapphire all the way to the Dohmann Helix and Air Force Tables. I think Thorens makes a few at a lower price point. A good suspended table should be immune to everything up to an elephant stepping on it. I can bang the side of my Sota with a hammer and it will not skip and you won't even hear it through
the system. 

Mahgister, Ron Carter is not in your room. You have no where near the power and the wrong kind of loudspeakers to image a full size acoustic bass. The best you can do is come up with a miniature version. But, do not feel bad. That is the best most systems can do. If you want to head in the right direction buy a pair of Magneplanar 3.7i's and the biggest amp you can afford over 200 watts/ch.

Cleeds, yes I read tea leaves but most importantly systems like mine are obviously very rare at this point. Few understand the basic issues involved so I am left waving the flag by myself. Which is ok by me. Anyone can ridicule me all they want. Until they have lived with a system like mine they have no idea. Now, people are always bragging about how great their systems are. La De Da. I could give two hoots about what people think about me or my system. I am only trying to give our members an idea about what is possible. But I'll also have to live with the fact that most people still think the earth is flat

Now cleeds, you seem to be confusing two issues. Good suspended turntables are immune to external factors. Like I said I can hit my turntable with a hammer with no ill effect as long as I don't hit it hard enough to cause a dent. Do not confuse this with the low frequency information that is on the disc in the form of warps and surface irregularities which a good system will try to reproduce blindly. If you have a system like mine which is dead flat at the listening position down to 18 Hz with 2000 watts driving each of four subwoofer drivers this spurious information will loosen the fillings in your teeth before it destroys your drivers. Blocking this information is I would think obviously critical in this situation. The only way this can be done without affecting the audio range is with a steep digital filter which I am fortunate enough to be able to program in my system. I hope this explained it adequately.

Mike

In the mean while, isolating your turntable will improve your signal to noise ratio and  if properly done protect it from nuisance issues like foot fall skipping. If your turntable is on a solid rack planted on a concrete floor the improvement will be less obvious. For those with wood joist floor construction a suspended turntable is the only way to go. 

You see cleeds, you have no idea either. Of course I am assuming wrongly or rightly, that all of you know what you are listening to. And cleeds, if there is no music by subwoofer cones are frozen dead.

Uberwaltz, if you could hear a proper system it would be the first thing you would be pursuing. 

Radomir Bozevic was a genius. His problem and downfall was that he thought everyone else was up to his level of thinking. He direct marketed his equipment, his instruction manuals were awful and he was not able to provide adequate phone in support although he tried. The TacT 2.2x and it's theater version he TCS remain the most powerful DSP preamplifiers on the market. The only units that are close are those made by Trinnov.
Companies like Anthem and DEQX make units that are relatively easy to use but not near as powerful. They are however very useful in mid Fi situations. In Top systems only TacT and Trinnov need apply at least for the time being. I will take photos of the program in operation to try and give everyone an idea of what is going on. 

 The absolute finest systems have flaws directed signal processing can correct. Even Michael Fremer admits that processing done at          192/24 or faster is invisible. The central possessor in the Tact operates at 192/48. There are processors now that operate even faster. The Trinnov operates in 64 bits which will give it the power to correct problems more severe than even the TacT can handle. These processors do not excuse you from proper room and system setup. All that has to be done in conjunction. In the very best systems you would think the tolerances would be much higher and thus the speaker's outputs would be closer to identical and given close attention to room symmetry the advantage of a processor would diminish at least until you tried to add subwoofers. Without this type of capability you would not be able to make bad recordings more listenable and you would have no way of dealing with loudness issues other than playing the recording at the right volume. 

Uberwaltz, if you put the resonance frequency anywhere within the range of 20 to 150 Hz you are likely to make a change in the way you perceive bass. If everything else is set up correctly and of reasonable quality it is hard to believe that would make an improvement in overall balance or "tightness." If the resonance frequency of the suspension is down where a whole bunch of turntable designers think it belongs it should not change the tonal quality of the music but rather improve signal to noise ratio and and response to physical insults. The main purpose of a suspension is to limit interaction with the environment. 

Rix, just how would you address that?

mitch22,
Sorry I did not respond to you earlier.
This is just in regards to bass. Low frequencies in air are more powerful than most people think. Get a set of test tones, a test record, CD or download. Play a 30 Hz test tone and turn it up. You will hear everything in your house rattle. Go to the room farthest from your system and that room will also be rattling! My point is that putting you sub woofers on spring is not isolating anything from the bass. Springs or no springs the house rattles just the same.
It would be difficult to AB a spring situation correctly. So it is difficult to prove or disprove to yourself or anyone that springs improve the sound of a system. Just changing the height of the main speakers is enough to change the sound. Putting springs under your amplifiers will do absolutely nothing. You may be able to prove this to yourself by listening to your system with and without springs under just the amps. You should be able to set and reset them quickly enough. When you do this you have to be very honest with yourself. 
Never believe just what someone hears. Human hearing is way to variable to be trustworthy. You even have to be careful with groups of people. You can't even trust yourself so you have to be very careful when you do these experiments. Not to mention that all those springs look butte
ugly.
Cheers, Mike

indranilsen, the devise that has to be level to prevent skating forces is the tonearm. So the best place to put your bubble level is on the tonearm board or plinth right at the base of the tonearm. If the platter is a tiny bit off it won't matter. 
It is absolutely possible to completely eliminate footfall sensitivity. It just requires careful engineering. Any of the suspended Sota's, SME's and Basis turntables will do this. I can take a Sota Sapphire put it on a collapsible card table on a wooden floor, jump up and down in front of it and absolutely nothing will happen other than the suspension bobbing just a little. If you put a MinusK platform under your turntable you will get the same result. Can you make a suspension that will work as well? Absolutely. But, you will have some work to do and you will have to spend some money. I have a design for a suspended platform in my head. The form is easy. It is getting the right spring rates for a given weight and applying damping that are the difficult part. I would use a quartz solid surface material laminated to MDF. This makes a very well damped panel for the base and platform. The spring hangers would be 1" aluminum laser cut to shape, drilled and tapped then anodized. These would be mounted on the base at the corners and the platform hung from them with the springs. On the bottom of the platform I would mount paddles at each corner which extend into cups mounted on the base. These cups would be filled with a viscous oil to provide damping. Soft rubber boots hung from the platform extending over the cups will provide a seal to keep dust out of the oil. There you have it. I should think it could be built for $500 in materials. 

The real problem is subwoofers. You have a significant mass vibrating +- 2 cm.   Any vibration of the enclosure is distortion. This is for any speaker, if you feel the speaker vibrating you have distortion. Putting the speaker on springs will make it worse. Fixing a heavy mass to the top of the speaker will lower the frequency it vibrates at, get it low enough and it becomes insignificant.  This does nothing for cabinet resonance, vibrating panels. This is avoided by thoughtful design.

Your tympanic membrane moves immediately in conjunction with the pressure front created by whatever frequency of sound you care to talk about including bass. This movement occurs immediately and does not wait for a full wavelength to pass. But, it does take a period of time before the sound is registered and interpreted by the cerebral cortex. This probably occurs at the same time for all frequencies. Now, in deep bass it becomes not only hearing but feeling that are involve in assessing the sound. At some point it becomes only feeling if the volume is loud enough to register at all. 
The job of the enclosure is to isolate the woofer's rear from it's front waveforms so they do not cancel and to hold the woofer rigidly in space. Any movement of the woofer distorts the waveform. If the enclosure is sufficiently heavy and stiff it does not matter what it rests on. Unfortunately, that is a very difficult goal to reach so it is always best to anchor the subwoofer to a large immovable object like your house. 
The way I use my subwoofers is significantly different than say millercarbon. I cross over to them much higher at 125 Hz. This is up into the range that can be located. So my subs have to be arranged around the satellites in a symmetrical pattern to maintain a proper image. 
I also have to duplicate the radiation pattern of a line source so that the subs can keep up with the satellites as distance away from the speakers increases. It is certainly true that a bass instrument's higher frequencies and harmonics locate the instrument. The fundamental does not even have to be there. What goes AWOL is the sensation. I can make an EQ preset that chops everything under 40 Hz. Switching back and forth between the normal curve and the 40 Hz chop will not change what you here so much but all the sensation you get being at a live concert will disappear, gone. Those frequencies under 40 Hz are what makes music breath. Unfortunately, it is so easy to corrupt that end of the spectrum with room problems, phase inconsistencies, poor enclosure design and execution, and under powered amplifiers.  But, when you get it right it is a beautiful thing.

@Derek, that is the right way to set them up as dedicated right and left channels. What crossover point are you using ? You do no want to go too high. Some harmonics coming from bass instruments are up in the mid range. Certain sounds like strings tapping the fretboard may be up in the treble. Bass instruments are usually mix towards the center so both channels are operative. You can go mono with high crossover points because you will start messing with the image to some degree. Mono is not a problem with crossover points below 80 Hz as we all know that localization is difficult below 80 Hz. The sub also do not need to be arranged symmetrically around the satellites although to me asymmetry is visually disturbing. (there's that silly brain again). For people whose woofer driver carries a substantial amount of the midrange a higher crossover is a large advantage lowering distortion in the midrange. This is typical of two way speakers. Putting subwoofers under LS3 5A's is quite the experience. With your eyes closed you would swear it was a much larger system. You open your eyes and see those little things and you start looking for the other speakers.