What is the Science behind putting loudspeakers on spikes?

[Baldo]

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?

 

[staticV3]

#3 is the only one that makes sense to me.

Metal spikes which dig into the floor help couple the speaker to it.

I don't see how they could possibly decouple it.

 

[Ron Texas]

Spikes keep things from moving around if the floor is carpeted. Stand mounts would be unstable otherwise.

 

[Baldo]

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.

 

[Multicore]

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

Not as far as I know.

Spikes can be a useful option if you have carpeting. Stands can be wobbly if you just put the legs on top of the carpet. Spikes that go through the carpet can get rid of the wobble.

 

[Ken Tajalli]

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.

Well yes, if you want to.
I have been doing this for the past 30 years!:
- Get a heavy slab of Granite (good-looking expensive) or a paving slab (not good-looking, cheap) or anything in between.
- Use thick Sorbothane (soft gel pads) or any cushioning material, that wouldn't quash to destruction easily under heavy weight, place the compliant pads on floor, place the heavy slabs on them.
- Put your speakers, with solid feet (not compliant) directly onto slabs, making solid contact.
How it works, the science:
- In theory! the heavy slab/speaker, due to its sheer high mass, would have a high stationary intertia. Any vibration from the speaker or the floor, would get absorbed in the pads, hence decoupling them.
To a degree . . . .
Works very well for Turntables too.

 

[Drengur]

This thread could maybe help.

 

[Ken Tajalli]

This thread could maybe help.

And this:

Speaker enclosure vibrations - a few measurements with accelerometer

There are been quite a number of threads dealing with vibrations in speaker cabinets, both in relation to "speaker feet" and vibrations in enclosures themselves. I recently took out my ACH01 accelerometer to do some measurements, both speaker feet and enclosures. There was some initial...

www.audiosciencereview.com

 

[DVDdoug]

I don't believe think they do anything acoustically. If they change the height that can make a change in sound but you'll get a bigger difference angling or tilting your speakers towards (or away from) you ears.

The vibrations from the box cabinet are small compared to woofer movement and any sound coming from the box is usually drowned out. If you hear a cabinet resonance it's usually the air space inside the box with the sound leaking through the drivers/port.

If your floor is vibrating it's usually the soundwaves in the room vibrating the entire floor area.

If you have a speaker on a shelf or desk, sometimes something on the shelf/desk vibrates/resonates. Isolation or mass is the solution, not better coupling to the desk/shelf. Or fix whatever is vibrating.

Spicks should make it feel more stable when you push on it because it's not going to tilt until a pair of spikes comes out-of-contact with the floor. The carpet can give a little with less force.

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?

Generally, you want to isolate a turntable. If you put a turntable on top of a speaker you sometimes get feedback. Springs or rubber feet can help, or mass (a concrete stepping-stone or something) will lower the resonance and perhaps eliminate the feedback.

Or sometimes with a wood floor the phono cartridge can pick-up footsteps and they get amplified. Again, isolation or mass, or a shelf attached to the wall can help. Hard-coupling to the floor can make it worse.

CD/DVD players can sensitive to shock. A CD player in your car will sometimes skip over a bump but they are not sensitive to sound vibrations.

Some tubes are "microphonic" and they'll make a noise if you "flick" them with your fingernail, etc., and maybe in extreme situations they can pick-up sound vibrations. But tubes (like turntables) are outdated and "dumb" anyway.

Occasionally capacitors can be similarly affected by a shock, but I've never heard of a capacitor picking-up small sound vibrations.

 

[Justdafactsmaam]

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?

Spikes couple the speakers to the floor so if you use spikes to decouple speakers from the floor you are going to be very disappointed. While they can in theory make a speaker cabinet more stiff in relation to the driver I’m not sure there is any evidence that will be audible.

Coupling a speaker to the floor can have substantial audible effects on the floor and walls though. If you want to rattle the room use spikes.

 

[Mikig]

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.

 

[DubZ]

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

I've read 1 before too. Hammer a 2mm nail 20mm into a timber floor and try to move it with your fingers, or just hammer it in 1mm and try to move it sideways. Does it seem coupled or decoupled?
My speakers are on cones because they're tall and narrow and I needed outriggers for stability. They weigh 40kg each and they're not going anywhere. I'd say they're pretty coupled.

 

[Speedskater]

IF the spikes tightly couple the loudspeaker to the floor, that effectively increases the mass of the speaker by a lot! which reduces cabinet vibrations.

 

[Petrushka]

My KEFs have spikes and “rubber” bumpers that can be screwed out to protect wood floors. I choose not to put holes in the floor.

I didn’t see this mentioned, but rubber feet put semi-permanent dents in carpet.

None of this has anything to do with sound.

 

[Justdafactsmaam]

IF the spikes tightly couple the loudspeaker to the floor, that effectively increases the mass of the speaker by a lot! which reduces cabinet vibrations.

It just does a more efficient job of sending them to the floor. The benefits and drawbacks will depend on what the floor does with that energy

 

[Petrushka]

So spikes couple the speaker to the floor and also decouple it.

A well understood phenomenon.

 

[olieb]

So spikes couple the speaker to the floor and also decouple it.

The decoupling part is a myth.
And I never understood why one would want to couple the cabinet to the floor. (unless living on an inclined plane)

 

[staticV3]

So spikes couple the speaker to the floor and also decouple it.

A well understood phenomenon.

Apparently not.

Spikes do not decouple speakers.

Only elastic mounts are capable of decoupling. Springs, dampers, rubber, elastomers etc.

Spikes are fully rigid and therefore perfect couplers.

 

[akamatsu]

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

 

[Justdafactsmaam]

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

In that case it is solving a non-problem.