Spiking Your Speakers: What’s the Point?

[drkrack]

Good you brought us back on topic @drkrack . Curious why you signed the post as @Yelamanchili manohar though?

Manohar has max experience with Isoacoustics, Townshend and DIY platform for his DIY floorstanders, and his inputs will be valuable

 

[keith_correa]

Come to think of it, it is exactly the same reason why planes fly. When the speaker cone moves forward, it compresses the air in front of it. The compressed air then exerts a force in the opposite direction.

Same thing helps planes fly. The Jet turbine burns fuel and the compressed burnt fuel comes out from the back causing the compressed burnt fuel exert force on the plane in the opposite direction. The plane moves forward because it is not resting on spiked feets. The wings are tilted upwards. This cause air to get compressed in the downward direction. The compressed air the exerts force on the wings in the opposite direction and thus lifts the wings up and voila the aeroplane gets lifted into the air.

This is all Bernoulli ka Kamal who was the first to study fluid dynamics and explain it. https://en.wikipedia.org/wiki/Bernoulli's_principle

I understand that; I think by movement you mean the driver frame vibrating, right? Those vibrations are transmitted to the enclosure - the intensity of transfer depends upon how coupled/decoupled the driver is from the enclosure. Now, IMO, at sane levels, the effect of this on the sound is very minute to say the least.
More intense is the energy inside the box that is also transmitted to the enclosure which results in spurious "noise" - which again depends on how the enclosure is constructed and the material.

 

[sidvee]

In all these discussions, the main point should be, is all this physics/newtons laws etc etc. audible or not? If not, other than scientific curiosity, it becomes the purview of snake oil peddlers at best. At the end of the day - is it improving the sound in an objective/ reproducible/repeatable manner (if any six sigma black belts in our forum its gage R&R test) - is all what should matter, imo? I have a lot of footers, thing-ma-jigs, stands, factory spikes, after market spikes etc etc. with all the money invested in those things, I can perhaps buy a pair of nice speakers. Yet I can probably discern maybe 1-2% improvement with Wilson Sabrina's. Maybe I need to move to $40,000 speakers to hear all these so called improvements.
Cheers,
Sid

 

[keith_correa]

In all these discussions, the main point should be, is all this physics/newtons laws etc etc. audible or not? If not, other than scientific curiosity, it becomes the purview of snake oil peddlers at best. At the end of the day - is it improving the sound in an objective/ reproducible/repeatable manner (if any six sigma black belts in our forum its gage R&R test) - is all what should matter, imo? I have a lot of footers, thing-ma-jigs, stands, factory spikes, after market spikes etc etc. with all the money invested in those things, I can perhaps buy a pair of nice speakers. Yet I can probably discern maybe 1-2% improvement with Wilson Sabrina's. Maybe I need to move to $40,000 speakers to hear all these so called improvements.
Cheers,
Sid

I agree 100%!
There's the science and the math and then there's the audibility of this effect. Maybe there are some to whose ears these are audible - who can say? There are too many variables in play that may determine the audibility of the effect.

 

[sidvee]

I agree 100%!
There's the science and the math and then theres the audibility of this effect. Maybe there are some to whose ears these are audible - who can say? There are too many variables in play that may determine the audibility of the effect.

Then statistically that audible effect in invalid. I work in the pharma industry, a statistically invalid test means that a drug will not work - period, no second guessing, no - this is what I feel, no this is what I think etc. etc. It's many lives at stake. Of-course our hobby is less life threatening, so it's ok for subjective opinions - and here is where snake oil peddlers step in - but I am digressing. Unless you can hear it with your own system - spiking, coupling - de-coupling, hanging from ceiling etc etc. are all subjective opinions - one has to experience for themselves and choose what they prefer - there is no one definitive solution.
(and it reminds me - I got it into one terse exchange with another FM who wanted to know how my bedside night-stands were effective speaker supports (they are solid wood and weigh about 50kgs) when all the so called reviewers refer to steel stands etc etc. that cost an arm and a leg, as the best supports, that somewhat magically make sound-stages/imaging better and even the speaker itself better - discussion for another day - but shows how contentious these issues become)
Cheers,
Sid

 

[mbhangui]

I understand that; I think by movement you mean the driver frame vibrating, right?

Yes. That's what I meant.

Those vibrations are transmitted to the enclosure - the intensity of transfer depends upon how coupled/decoupled the driver is from the enclosure. Now, IMO, at sane levels, the effect of this on the sound is very minute to say the least.

My ears too cannot make out any difference with spikes, without spikes, on rubber feet, etc. And I don't bother. I have removed spikes because it makes it difficult moving it on my carpet. Only place where it has made a big difference is my powered subwoofer. The bloody things moves around the room when playing movies.

But maybe other people are hearing a difference and that's is something I can never know if my ears cannot hear it.

More intense is the energy inside the box that is also transmitted to the enclosure which results in spurious "noise" - which again depends on how the enclosure is constructed and the material.

Indeed.

 

[Passive_audio_enthusiast]

When you say "low compliance" - what exactly doesn't it comply fully with?

A smaller contact area causes a lesser amount of vibration transfer at a point in time so why will hexnuts (or spikes for that matter) dissipate vibrations easier (better?) than resting the whole frame (in your case) on the floor?


If it reduces then it can only mean 1 thing:
the residual energy still exists either waiting to be dissipated over time or is dissipated immediately into another medium.

Yes, it’s dissipated to the air but since air doesn’t resonate like a floor this becomes a non issue.

Try waving your palm in the air. Try hitting a wooden table with the same palm with the same force you used for waving. While waving in air you hardly hear any sound. While hitting on the table you hear the sound.

 

[Hari Iyer]

When you say "low compliance" - what exactly doesn't it comply fully with?

A smaller contact area causes a lesser amount of vibration transfer at a point in time so why will hexnuts (or spikes for that matter) dissipate vibrations easier (better?) than resting the whole frame (in your case) on the floor?

Stiffness is inverse of compliance. Low compliance also mean high stifness. The box stays rigidly coupled to the floor.

When the box stays fully on floor it will also pass low frequency vibration to the floor which needs to be avoided. Having a SS hexnut prevents that and only MF and HF( if any) vibrations gets transferred to floor. At LF the box will still vibrate and colour the bass a little. IME trying to over damp this panel vibration does not sound good. There is a delicate balance for damping panel vibration IME. I use interlocking joints for the box for panel vibration to be equal in the box.

 

[arj]

If a bookshelf speaker (10kg) on a stand (20kg) with metal spikes on a smooth ceramic tiled floor and playing Massive attack continuously at 90db avg for a week, how far would the speaker move?
Advancing the frontiers of Audio science with such research questions is important work.

I doubt the speakers will move at all, but considering the drivers are vibrating at so many different frequencies to produce that sound, can some of it be affected by the slightest due to the cabinet vibrating , especially in the 50hz+ range ? perhaps yes

Is this dependent on the driver ? again perhaps yes as the thinner the driver material more it gets affected by cabinet waves ( eg Lowthers or old drivers) than for the newer thicker material used with High powered amps.

Dependent on Cabinet constructions..again yes either the frequency or the amplitude of these vibrations would be dependent. on heavy well braced/damped cabinets it will be very less on thinner/pure wood cabinets a bit more.

Will it affect the more pronounced waves or the more sensitive smaller amplitude ones ? perhaps the latter and hence the more delicate frequencies including harmonic content

Will it be dependent on the floor and coupling of the speaker to it..Perhaps yes depending on how the speaker is able to damepn/dissipate its own vibrations based on that coupling/decoupling

Should you care ? yes if you can hear a difference and is audible..and no if not

 

[keith_correa]

To my mind, if the effect of the physics of this is at all audible, the efficient way is to rest the speaker on a compliant dissipating viscoelastic polymer like sorbothane to damp bidirectional vibrations and be done with it.

 

[Analogous]

To my mind, if the effect of the physics of this is at all audible, the efficient way is to rest the speaker on a compliant dissipating viscoelastic polymer like sorbothane to damp bidirectional vibrations and be done with it.

Isn’t this what companies like Isoelectric make as footer pucks?
So essentially a decoupling approach?

 

[arj]

To my mind, if the effect of the physics of this is at all audible, the efficient way is to rest the speaker on a compliant dissipating viscoelastic polymer like sorbothane to damp bidirectional vibrations and be done with it.

Isn’t this what companies like Isoelectric make as footer pucks?
So essentially a decoupling approach?

Very much so , as mentioned by keith there are different materials used. people have talked about Felt, EVA , sorbothane..and maybe even more.
Some speakers like Wilson, VonSchwiekert , magico et all have special materials which might require a different treatment most speakers might benefit from this..spikes on wood seems to be popular.
My earlier speakers were Merlin Bookshelves and they were recommended to be keep on heavy stands with bluetack which Couples/decouples. Even ATCs/Harbets etc are recommended with open frames which can dissipate energy hence may need loose de-coupling from floor to make it more effective etc

 

[coaltrain]

My four previous speakers came with thin sharp spikes that were practically useless on a marble floor. Bump into them and they could change position, and I always felt they would topple over if pushed hard.
The Lintons come with fat brass cones and brass pucks with a bit of felt underneath. Peter Comeau recommends four Blutack ‘peas’ to secure the speaker to the stand, which is what I’ve done. With a combined weight of ~33 kgs, the speakers are immune to my fat-bottomed friends. Yet, they can very easily be slid around to fine tune positioning.
I have no idea how this setup affects the sound, but it sure is the most practical one I’ve had in my living room.

 

[Analogous]

Very much so , as mentioned by keith there are different materials used. people have talked about Felt, EVA , sorbothane..and maybe even more.
Some speakers like Wilson, VonSchwiekert , magico et all have special materials which might require a different treatment most speakers might benefit from this..spikes on wood seems to be popular.
My earlier speakers were Merlin Bookshelves and they were recommended to be keep on heavy stands with bluetack which Couples/decouples. Even ATCs/Harbets etc are recommended with open frames which can dissipate energy hence may need loose de-coupling from floor to make it more effective etc

@arj, you have opened a whole new dimension- on that which comes before the spikes and footers

Warrants a Separate thread/discussion?

 

[alpha1]

Momentum of what? Conserved?
Opposite to what direction?
Can you explain or elaborate more?

Yes certainly.
First we need to define some properties of mechanics:
1) Mass = amount of matter. In other words how massive & heavy an object is
2) Displacement = distance moved along with the direction specified
3) Velocity = speed with direction specified
4) Acceleration = rate of change of velocity, in other words even if the speed remains same but the direction changes, it is accelerating (e.g. rotation).
5) Momentum = product of mass and velocity; this is what is felt when you crash into something, or conversely something crashes into you
6) Force = product of mass and acceleration; this is what causes any change in speed or direction

Now, when there is no external force acting on a "system", the momentum of the "system" remains unchanged. (e.g. If the ball is rolling, it will continue rolling unless friction slows it down)

Let's define the system as "driver + speaker box enclosure". It is at rest, which means zero movement. Unless there is an external force on this system, the system (combination of driver + enclosure) is going to continue having zero momentum.

//Side note
The momentum (or velocity, or acceleration, or force, or any such property) of such an aggregate system is summation of individual components.
If the driver moves 1 cm northwards, and the enclosure moves 1 cm southwards, then the "system" moves 0 cm.
If the driver moves forwards by 1 cm/s and the enclosure moves backward by 0.5 cm/s, then the "system" moves forward by 0.5 cm/s
//Side note ends

If the driver (100 g) moves 1 cm forward, and the speaker body (10 kg) moves in in backward direction by 0.1 mm, the momentum continues remaining zero. And this is what happens in real life. Therefore, relative to the stationary air, our driver should have moved 1 cm forward, but it actually moves only 0.99 cm forward.

 

[RRR]

Waiting to hear where does Isoacoustics Gaia fit in this coupling/decoupling and why does it make such a big difference as claimed by most.

 

[arj]

It will make a difference all right but good or bad, Worth it or not depends on the speaker and resolution of the system