Suspensions on turntable...really effective?

Actually, magnetic suspensions on the tables I have seen are effective only in the vertical direction.  The platter is held in place by a spindle in a vertical bearing.  There is virtually NO movement permitted horizontally by that bearing.  The magnets support the platter only allowing for up and down motion.  If you press down on the platter it moves downward, but, the magnets act like a spring.  The farther the platter is displaced downward, the closer the magnets move and the greater the opposing force, and hence the force trying to restore the platter to the equilibrium position (like a spring).

With all due respect to the OP, the question posed is a bad one from a scientific point of view; it cannot be answered simply or with a simple experiment.  The responses that go in all possible directions so far are consistent with that fact.  The huge variety of turntable suspensions (also counting no-suspension as a form of suspension) offered in the marketplace is further evidence that there is no "correct" answer to the question.  In my opinion, those who try to develop suspensions for turntables must be very brave; it's a pit of snakes.  No matter what one does, there is a new problem that comes with it.  Personally, because of this, I favor unsuspended turntables, massive plinths, heavy duty shelving, concrete floors, etc.  If you can afford a Vibraplane or Minus K, they're probably superior to most built-in suspensions but not perfect.  For one "concrete" example, I've set up a second system in my basement, on the poured concrete flooring.  This did great things for image solidity and reducing spurious noises that can be produced when the needle is disturbed in the groove, with a Lenco that I had earlier auditioned in my "upstairs" system.

A few guys mentioned great bass from a Linn. While I can like the sound from a well set-up Linn, I always find the bass to sound "light", not to say lacking.  I've owned a SOTA Star Sapphire Series III; the bass was downright muddy, could as well have been due to belt stretching as to suspension flexing.  However, I do agree that later generation Sota's are better in this respect.

The bass produced my Linn Basik/Akito rig is astonishingly good…why? Is it the Mogami din plug cable I put on it to replace the original that had actual rat bites (!) through to the wire? Is it the Sumiko Pearl cartridge that was embarrassingly inexpensive by any elitist geekdom standard? The relatively el cheapo (a pattern…I see a pattern here) Cambridge 640P/Pangea P100 (power supply) preamp? Why? Why?

diamondears - Suspensions on turntable.......really effective ?

I think that the OP - diamondears is thinking about what type of shoes the turntable is wearing ? Women have this thing for shoes you know. But truth be told I think I do too. My SP10 MKII has worn maybe 15 sets of shoes during past bouts with audiophilia. Each set of 3 shoes transformed its’ personality each time. Yes, turntables have three legs. Well, they only need three legs. We have all heard the term "clothes make a man". How about shoes make a TT ?

Geoffkait
But we know that magnetic fields are bad for the sound especially in proximity to low level signals. For that reason I’m out.

Oh no....

Every low level signal phono cartridge consists of key components: the stylus, cantilever, MAGNETS, coils and body. What are we going to now GK......you better go tell every cartridge maker about this.

Now the platter itself on my La Platine is this big aluminum thing, and I think it isolates pretty good as it allows me to use a direct shot of unshielded phono wire.

Geoffkait Of course the other objection is the very slippery nature of the opposing magnets doing the levitating.

Well, I can tell you that La Platine is anything but slippery. In fact the opposing magnets provide braking action to deal with the records behavior, at the record location. Do any others do this ? Kinda cool. The distant motor happily provides pulses of power through loosely applied thread. It can be plucked while the record is playing, and so far no listening can tell I am doing it.
This is really fun to do with Audiophiles that are used to "loading" up the record, "loading" down with heavy clamped center weight and heavy peripheral weight; ready now, activate speed controller, ready, ok. push start ........at speed in milliseconds ......

La Platine - very much like a little girl pushing 6 - 200 lb guys on a playground merry go round.
hey its a unique experience - not for everybody.

sidenote
Audiophiles are immediately attracted to La Platine because all the family jewels are exposed, accessible, and they think..oh my .. so much to access and modify here.
The problem is ...from what I have heard .....true audiophiles all end up doing the same thing with her... they mess too much with the design...they go to far, and they then get bored because they have destroyed its genius dna, and created "audiophile bedlam".

You heard it here first.

Thanks for the responses, all. 

What I'm looking for is some white paper or really comprehensive post or thread discussing the merits (and demerits) of suspensions on turntables. 

Primarily, I'm wondering how spring suspensions could isolate from vibrations when the spring itself is still connected from one end to the other end? Re magnets, when the magnet moves, so does what's on top of it?