John Sayers' Recording Studio Design Forum Archive

It may be a very silly question, but recently I was looking at some DIY projects on hovering beds using very strong magnets to float on the air.

So could a truly floating floor be constructed using magnets zeroing the vibrations from a live room to the floor? I have no knowledge on the subject so it would be interesting to know if this is a valid question

Hi "diaolosh". Please read the forum rules for posting (click here). You seem to be missing a couple of things!

That's actually an interesting question! I don't know enough about magnets to be able to answer for sure, but considering that some trains are levitated on powerful magnets, I don't see why it wouldn't be possible to do the same with a studio floor. It would be prohibitively expensive, for sure, and I'm not sure you'd want extreme magnetic fields in a studio, as they would wreak total havoc with speakers, wiring, hard disks, tapes, and pretty much everything else. But in theory it should be possible. Acoustically, it would be great since it would eliminate the higher resilience of rubber and metal springs, leaving just air and the magnetic field to act as the spring in the MSM system,...

- Stuart -

Drop anything metal on the floor, good luck on ever getting it off the floor.

Drop anything metal on the floor, good luck on ever getting it off the floor

Very true! Also, don't use boots with steel toes... or any shoes with steel nails in them...


- Stuart -

Soundman2020 wrote:Hi "diaolosh". Please read the forum rules for posting (click here). You seem to be missing a couple of things!

That's actually an interesting question! I don't know enough about magnets to be able to answer for sure, but considering that some trains are levitated on powerful magnets, I don't see why it wouldn't be possible to do the same with a studio floor. It would be prohibitively expensive, for sure, and I'm not sure you'd want extreme magnetic fields in a studio, as they would wreak total havoc with speakers, wiring, hard disks, tapes, and pretty much everything else. But in theory it should be possible. Acoustically, it would be great since it would eliminate the higher resilience of rubber and metal springs, leaving just air and the magnetic field to act as the spring in the MSM system,...

- Stuart -

Speedskater wrote:Drop anything metal on the floor, good luck on ever getting it off the floor.

Hey Soundman, hope I fixed it !

I'm sure there will be a massive magnetic field that will mess up with every speaker and whatnot. Hell, even pacemakers :-S

Setting this aside ,hypothetically speaking, would that make the best decoupling method , producing zero vibrations no matter how loud it would get?

producing zero vibrations no matter how loud it would get?

Nope! The magnetic field is still a spring. The air is still a spring. Springs will still transmit acoustic energy across from one side to the other. If you did manage to get your magnets to work (without ripping all the nails out of the room framing.... then your floor would just be the same as the walls: mass on both sides, with an air gap in between. It would still be governed by the same laws of physics as all MSM systems ("Mass-Spring-Mass"), and would still need to be tuned in the exact same way as the walls, ceiling, windows, and doors in your room. I'm not sure how you would measure the resilience of the magnetic field, but I would imagine that it would be similar to that of other resilient mounts, and since it is acting in parallel with the air spring, it would reduce the overall effect, thus increasing the coupling.

There's no such thing as a free lunch! There are no magical materials or techniques that can bypass the laws of physics. They will get you every time, one way or another....


- Stuart -

You could probably do it, but my guess would be that a maglev system wouldn't provide any benefit over a traditional spring system, assuming that the stiffness of the two systems was the same. Maglev is beneficial in transportation because it eliminates the friction between the wheels, tracks, and suspension systems, but those aren't concerns with a stationary floor.

If you'd do this the right way you don't have to worry about fields and metal falling to the floor. When you need to airship speakers with strong magnetics fields stacking 'm so the magnetic fields are out of phase will eliminate stray fields. That would happen in the floor-room case, IMHO
You could also consider using electro-magnets .
I have a buddy who is a speaker engineer, I'll askhim about the practical problems

bert Stoltenborg wrote:If you'd do this the right way you don't have to worry about fields and metal falling to the floor. When you need to airship speakers with strong magnetics fields stacking 'm so the magnetic fields are out of phase will eliminate stray fields. That would happen in the floor-room case, IMHO
You could also consider using electro-magnets .
I have a buddy who is a speaker engineer, I'll askhim about the practical problems

Phase cancellation was something I also thought although I couldn't figure how it would work on a practical level

DanCostello wrote:You could probably do it, but my guess would be that a maglev system wouldn't provide any benefit over a traditional spring system, assuming that the stiffness of the two systems was the same. Maglev is beneficial in transportation because it eliminates the friction between the wheels, tracks, and suspension systems, but those aren't concerns with a stationary floor.

Please , correct me if I'm wrong. A floating floor should not be stationary. Based on that there's friction. Isn't the air transferred friction on the magnet system much less than the mechanical in the spring system?

At least in theory, its all hypothetical

A floating floor should not be stationary.

You certainly don't want your floor to move! Where would it go? And you certainly don't want your floor to "bounce" either. Floating floors should be steady, not moving. The point of a floating floor, is not that it moves: the point is that it decouples at the frequencies where it needs to decouple. It does not need to move in order to do that. What the floating system does is to isolate vibration caused by sound waves. The "movement" that that produces is very, very small.

Based on that there's friction.

There's no friction involved in the way a floating floor operates. It turns some of the sound energy into low-grade heat inside the damping system, and to a lesser extent inside the "spring", but there's no physical contact going on here, so hence no friction.

Isn't the air transferred friction on the magnet system much less than the mechanical in the spring system?

The air does not transfer friction: the air transfers sound energy, just like the magnetic field does, and just like any other spring does:
That metal spring in the animation above could be a physical metal spring, or some form of rubber, or air, or a magnetic field, but it still works the same way: the spring transmits energy between the two leaves. You want it to transmit as little energy as possible, of course, which is why you choose your MSM resonant frequency to be as low as possible, and also why you choose the least "solid" spring possible.

In a wall, that spring can be air alone, but in a floor it needs to also include some other "spring" that can actually support the floor deck itself.

It seems you are confusing the stiffness and resilience of the spring, with friction.


- Stuart -

diaolosh wrote:

DanCostello wrote: A floating floor should not be stationary. Based on that there's friction. Isn't the air transferred friction on the magnet system much less than the mechanical in the spring system?

I think you're wading into semantic territory. Yes, technically, if there's motion of any kind, there's also going to be friction. But it's going to be negligible. The friction in a train's wheel assembly, however, is pretty high.