Speaker Spikes - Working Principle


Vibration damping obvious makes sense (in speakers just as well as in cars). 

That involves 'killing' (converting into heat, through typically internal friction) kinetic energy. So any sort of elastic material (rubber has lots of internal friction) makes sense. 

And then there are spikes. Using a pointy hard object and pair it with a softer, elastic material (to deform, and kill kinetic energy) can work; think metal sharp spike into carpet or wood floor. 

But what is the idea behind pairing fairly unelastic metal (brass for example) with similarly unelastic (brass, stone, etc) material (example photo provided)? Only thing I can come up with: LOOKS good and makes owner feel good  thinking its an improvement (works only for Audiophiles though),

Even more curious: are they ENGINEERED "spikes" (vibration dampers or shock absorbers) for speakers that are TUNED for the frequency (and mass)  that needs to be dampened? Can piston style fluid dampers be designed for the high frequencies (100, 1000, 10000 Hz) using geometry, nozzles size and viscosity of the fluid?

 

kraftwerkturbo

This is my thought when trying to overcome the debate of coupling vs. isolation.  My experience of having floor stander speakers on a second story suspended wood floor with carpet was a challenge. I tried spikes, no spikes, limestone pads with spikes and no spikes and Herbies gliders.  The floor would pick up vibrations and transmit them causing some strange room nodes in the bass.  I finally mitigated the problem by using Townshend podiums which de-coupled the speakers from the floor.  So I'm a big fan of isolation at least in my situation.  

Article from Positive Feedback on misconceptions regarding spikes reinforces using isolation products rather than coupling products (spikes) for improved SQ.  The article’s summary and link are below.   There are many good speaker isolation  products such as Isoacoustics, Symposium, Townsend, etc.   I personally use Townsend Seismic Platforms and can attest they perform as advertised making a remarkable improvement in all areas of SQ. Note I copied link but when I preview a graph appears rather than the link.  When I click on graph the article opens.  If the link does not work contact me and I will type it rather than copy it   Sorry.  

PF Summary:

  • Rigid feet couple vibrations
  • Vibration is a two-way street
  • Spikes cannot drain energy to a heavier mass
  • A small contact point actually amplifies vibrations
  • Spikes cannot reduce internally generated cabinet vibrations
  • Question one-size-fits-all and no lab report devices
  • Isolation means the mechanical path is either broken, or the form of energy is converted to another form
  • Properly designed isolation is predictable, repeatable, and neutral in performance
  • Isolation will offer clarity that cannot be experienced with coupling, because with coupling comes additional, unwanted vibrations
  • Isolation is easy to perceive
  • Vibration transmissibility is easily measured 

 

Before there was ever conjecture about spikes having anything to do with resonances, the purpose of spiking a speaker was simply to stop it rocking in reaction the motion of the drive units and to keep the speaker level. Since floors are rarely flat, spikes were seen as an economical way to achieve both goals.

A lot of lay intuition going on here.

Rubber has a lower internal impedance than say wood which is lower than concrete. The highest internal impedance I think is Diamond. 

Spikes do nothing but fix the speaker to the floor. This is only useful for subwoofers which can creep. If you use three spikes the speaker can not shake.

The issue is bass particularly with flexy floors and walls. If the floor's resonance frequency is within the range of the speaker it is going to vibrate every time that frequency is produced regardless of what you put the speaker on, even if you suspended the speaker in air. Put a test record on and play a 20 Hz tone at high volume and walk around the house. Everything that can vibrate at that frequency will sing. You will hear a symphony of rattles. Walk around the outside of the house and you will even hear the siding rattling. 

Anything that changes the speakers location in space can effect bass at the listening position and can change the speaker's sonic character. A little less mid bass can make a speaker sound more detailed as an example. Changes in location will also affect where all the early reflection points are within the room which again might change the speaker's character at the listening position. 

@ellajeanelle 

1+  You isolated your turntable from the resonance frequency of the surface you have the turntable on and also everything above the resonance frequency of your suspension. All turntables should be isolated this way. Ideally the resonance frequency of such a suspension should be 2-3 Hz which depends on the spring rate and the mass of the suspended Turntable. If a suspension device is not tuned to the weight of your turntable it may be worthless. 

Most of the stuff people put under audio equipment is purely for visual effect. If it looks cool it will sound better. Your ears and eyes are connected.  You certainly do not want to put a hot amp on carpet. 

Porcupine Tree (Steven Wilson's Band) has released a video of their performance of Closure/Continuation. There is also a CD of that performance. WOW!!! Gavin Harrison is a machine and IMHO the finest R+R drummer that ever lived. 

A couple months ago I took the spikes off my Revel F52`s and put Loctite Fun-Tak strips under each corner.

The speakers are now firmly coupled to the ceramic tile floor.

I`m hearing better bass definition and a more musical midrange.