Vibration isolation or absorption?

Thank you, Robert Maicks. 

@audiopoint

I am neither an engineer, nor a "Vibration Management Consultant", but I find some of the assertions in your above post to be dubious.

Springs, discs, pucks, squish balls, pads, cones, spheres, and all the materials have retailed in audio since the late 1980s.

All these devices are coupling products according to the empirical laws.

You are suggesting that springs, used in combination with dampers, are coupling devices?

Would you characterize shock absorbers, used on every car in the world, as coupling devices?

Böllhoff is a German company founded in 1867. They have produced vibration control products for many products over a very long period of time. Their products were used in early VWs, and on the Lunar Module used when Neil Armstrong and Buzz Aldrin became the first men to walk on the moon. Etc.

In reference to some of their current spring/dampening products, they say this (bold emphasis mine):

Vibration and noise decoupling

SITEC® Spring
The decoupling spring system with screw connection

Do you imagine that the engineers at Böllhoff are badly uninformed about "laws of vibration, motion, and gravity", or is the company making false advertising claims?

Here is a link to a patent of a "Vibration decoupling connection device", in which the word "decoupling" is used multiple times:

vibration decoupling device

I have the impression that you are playing semantic games, based on the suggestion that even the best designed springs/dampers are unable to completely decouple components from floors/racks, etc.

It may well be true that like shock absorbers, the best that spring-based isolation devices in audio can do is to greatly mitigate vibration. But there is no doubt whatsoever that, at least in the case of speakers, they can come far closer to decoupling than coupling devices such as spikes.

And as most audiophiles are, in fact, using such tools to "improve sound reproduction", your post strikes me as much ado about nothing.

@jumia 

Is vibration a two-way street?

So you have vibration from a speaker cabinet, but don't you also have vibration due to the sound waves bouncing around the room where the floor will vibrate and that vibration will transfer back into the speaker cabinet and also the component rack?

So maybe isolation is the answer?

Yes, you have all kinds of vibrations.

However I believe that the most serious ones are those usually coming from the loudspeaker cabinet itself.

Accelerometer tests have revealed that the loudspeaker baffle can be vibrating at far greater levels when that loudspeaker is placed on spikes as opposed to when it has been decoupled via springs or rubber.

Perhaps we could imagine the loudspeaker drivers acting like musicians standing on a vibrating floor? The less that 'floor' vibrates throre chance they have of performing with greater accuracy.

Of course there will be other vibrations that might affect the floor also but the ones coming from inside the box must surely be the most serious when it comes to smearing the sound.

It should also be noted that these days an increasing number of loudspeaker manufacturers are using laser inferometry to design their cabinets in order to limit these vibrations from acting on the loudspeaker baffle.

And then there's the thin walled BBC approach as used by the likes Harbeth, Spendor and Graham Audio.

The days of loudspeakers with terrible 'waterfall' graphs revealing poor construction seem to be over.

However, since my Tannoy speakers are over 40 years old, I'm not too surprised to find that decoupling works for me. Back then, the BBC research into cabinet construction had barely been published.

@audiopoint

I read your eloquent post. And I guess I am confused. I am not the brightest person so forgive me.

You seem to be taking a negative view on isolation and absorption merchandise sold by audio enthusiasts. And then in your final section you say that vibration management tools makes sense as part of the sound reproduction process.

Can you please clarify what you’re saying and provide examples of how someone would improvement to eliminate vibrations that are detrimental too good sound reproduction, which I’m sure exist somewhere.

Maybe another way to look at this, is to find ways to better manage sound dispersion throughout the room as well as minimizing vibrations that interfere with component performance, which is a more abstract concept I think. It is really easy to understand why you’d want to minimize external vibrations from a record Player as Jumping rope next to a record player likely interferes with a record being played, adding cushioning on the feet of a record player to prevent this seems like a good idea. Further, my subwoofer cabinet directly vibrates my floor which causes vibration noise from things on my shelf, an aluminum window frame, loose knickknacks, but if I put a squishy isolator disc thing between the feet of the subwoofer and the wooden floor it tends to absorb the sub cabinet vibrations and improve dispersion of pressure amplitudes more evenly throughout the room which is ideal for a sub.

Thank you

For me, Vibrapod work realy well under my speakers, on my suspended floor.          (speakers are just a little wobbly, but it is OK).  I also use Vibrapod with their Cone, with great success under my components.  Very good upgrade for the price.