What is the Science behind putting loudspeakers on spikes?

[akamatsu]

To decouple from the floor one could do what they do for optical tables. These are tables that a laser sits on for optical laser research.

Essentially you have a massive table top, often filled with sand for mass, which sits on inflated rubber inner tubes. You will often see these on trains as well. This prevents any vibrations from the ground filtering into the table. Vibrations where the wavelength is a few orders of magnitude great than the wavelength of light. These vibrations can put a lasing mirror out of parallel alignment effecting the laser.

So I am wondering if we have similar thing going on with vibrations but this time in the audio domain.

I've tested these tables. They performed best when all the air was taken out of the suspension.

 

[DVDdoug]

Spikes minimize the movement of the speaker cabinet. Less movement of the cabinet means more accuracy of the drivers.

My assumption is that it doesn't make an audible difference (in a blind listening test).

And probably not a measurable difference unless something is buzzing/vibrating. Sometimes that happens with speakers on a desk or shelf, but rarely with speakers on the floor. And then decoupling is the solution.

Most of the sound comes from the drivers making soundwaves in the air (and from the port in a ported speaker). A badly designed speaker can resonate but I think most of the "bad sound" leaks-out through the driver (or port) and not the direct-result of the cabinet vibrating.

 

[Justdafactsmaam]

I've tested these tables. They performed best when all the air was taken out of the suspension.

If you take the air out of a pneumatic suspension you don’t have a suspension anymore

 

[akamatsu]

If you take the air out of a pneumatic suspension you don’t have a suspension anymore

Yes. The suspension was causing problems and solving none.

 

[akamatsu]

My assumption is that it doesn't make an audible difference (in a blind listening test).

And probably not a measurable difference unless something is buzzing/vibrating. Sometimes that happens with speakers on a desk or shelf, but rarely with speakers on the floor. And then decoupling is the solution.

Most of the sound comes from the drivers making soundwaves in the air (and from the port in a ported speaker). A badly designed speaker can resonate but I think most of the "bad sound" leaks-out through the driver (or port) and not the direct-result of the cabinet vibrating.

In my experience, and in my system, it makes a huge difference.

 

[Saponetto]

The difference I heard was the sound of a broomstick beating my spine, when my wife got aware of the damages spikes caused on the parquet floor...

 

[killdozzer]

decoupling. Each material has a different frequency response. therefore the tips are used to have a smaller contact surface with the surface (stand, floor, furniture) on which the speaker is placed.

You've actually managed to be wrong AFTER a dozen commentators said it right. Amazing.

 

[killdozzer]

In my experience, and in my system, it makes a huge difference.

In your fancy. Not experience.

 

[killdozzer]

I have done this for many years but I forget what is the reason for putting our loudspeakers, especially floor standers, on spikes?

I have heard a few explanations:

1 to prevent vibrations from the loudspeaker cabinet being coupled to the floor by reducing the surface area of contact between the speaker and the floor, and/or

2 to prevent vibrations from the floor coupling into the loudspeaker, (similar to 1 above), and /or

3 to provide a solid and rigid contact with the floor to reduce the movement of the cabinet in the opposite direction to the speaker cone movement. This was explained to me by a physicist saying that as the cone moves forward, the cabinet wants to move back ie recoil due to conservation of momentum. So you provide resistance to this recoil.

Do these make sense? Are there any other reasons?

At one stage I can remember people putting even electronic components like Amps onto spikes. I can understand how turntables and even CD players would benefit from vibration isolation but amps and DACs?

Just think about the principle a tuning fork works on. Now ask yourself is it decoupling? A hard metal point on wood... It's not decoupling. It's for stability and mostly for carpets.

 

[Thomas_A]

Spikes minimize the movement of the speaker cabinet. Less movement of the cabinet means more accuracy of the drivers.

No. To achive that the resonance of the speaker-spike-floor needs to be above 20 kHz. In practice it will happen somewhere in the bass region. The other strategy is to put the resonance below the lowest frequency that the speaker puts out. E.g 2-10 Hz, which means using soft feet.

 

[Postlan]

Spikes are for coupling, not for decoupling.
Use something like Sorbothane for decoupling.

 

[sergeauckland]

Many years ago, I too thought spikes stabilised the loudspeaker such that the 'equal and opposite' Newtonian reaction to bass cone movement wouldn't cause Doppler distortion through the tweeter moving back and forth.

Then I calculated what the movement of a, say, 25kg loudspeaker would be to a few grams bass cone plus air load. The answer was one half of bugger all, so I stopped worrying about spikes and went on to castors, which are a lot more floor friendly and convenient.

I can understand decoupling a loudspeaker from the floor, especially a suspended wooden floor, or in a flat with people underneath, but that's the opposite of spikes.

S

 

[Petrushka]

As a carpet owner, spikes are to prevent permanent flat spots forming in the carpet. Their sonic effects are mythological.

 

[JeffS7444]

I always thought it had to do with Newtonian physics: F=MA, where F is Force, M is Mass, and A is Acceleration. Basically, as the speaker drivers push air around, they're also exerting equal but opposite forces on the speaker cabinet. But by removing any compliance between speaker and it's base via addition of spikes, you might effectively increase the speaker's mass. But I never tested this hypothesis in any systematic way, and I no longer do this because I'm tired of leaving scratches in the furniture!

 

[WillBrink]

As a carpet owner, spikes are to prevent permanent flat spots forming in the carpet. Their sonic effects are mythological.

And they look good compared to sitting on the carpet especially. Looks are part of the experience too. I mean, we still look at the gear more than we actually listen to it.

 

[Petrushka]

And they look good compared to sitting on the carpet especially. Looks are part of the experience too. I mean, we still look at the gear more than we actually listen to it.

I hate flat spots. I have some furniture pieces that have near spikes.

 

[Thomas_A]

I always thought it had to do with Newtonian physics: F=MA, where F is Force, M is Mass, and A is Acceleration. Basically, as the speaker drivers push air around, they're also exerting equal but opposite forces on the speaker cabinet. But by removing any compliance between speaker and it's base via addition of spikes, you might effectively increase the speaker's mass. But I never tested this hypothesis in any systematic way, and I no longer do this because I'm tired of leaving scratches in the furniture!

This was debunked 30-40 year ago, and forgotten; thus the spike myth still lives. There is no coupling that works > 20 kHz.

 

[krabapple]

I advocate conscious uncoupling, like Gwyneth and that guy from Coldplay did.

 

[Emlin]

I advocate conscious uncoupling, like Gwyneth and that guy from Coldplay did.

I've got a bottle of red before me, so hope to soon uncouple from consciousness.

 

[Soniclife]

I hate flat spots.

I recently discovered that steam mops (for hard floors) are brilliant at getting flat spots out that other methods didn't. Anything that produces steam will do the trick.