Vibration isolation or absorption?


You see those pointy things at the bottom of a speaker that are very very sharp.  Arguably a weapon in the wrong hands.  And then you see those same pointy things inserted into a disk.

So the pointy things, aka ‘spikes’ , can Channel vibration elsewhere and away from the components and speakers, or they can isolate it.

Seems channeling vibration away from a component/ speaker, which I guess is absorption, is preferable.

Is this true? And why do they keep saying isolation.

 

emergingsoul

Showing 8 responses by mitch2

@larryi nailed this from the first sentence:

Like almost everything involving vibration damping/control, it is a matter of tuning, so there is no definitive answer. 

I would add that there is also an associated component of personal preference.

@atmasphere eloquently added to the technical nature of the discussion:

I view this as 'points vs squishies' - Points are used to move vibration into the mass to which the point is pointed...Squishies are used to isolate

I have used many types of both points and squishies, starting with spikes and points early on, both on suspended wood floors and on concrete slabs on grade, and then in the past couple of years migrating toward being a fan of squishies, which are in essence a damped spring.  Vibration control is often modeled using springs and dampers. Damped springs are used for isolation of items ranging from delicate laboratory instruments to heavy duty industrial machines.  Your car has springs and shock absorbers (dampers). 

Years ago, you could read on this forum about folks using hockey pucks to "decouple" their speakers (fwiw - spikes were mostly referred to as providing coupling while everything else was referred to as decoupling). Former A'gon member Geoff Kait (i.e., Machina Dynamica) used to promote and sell springs for use under electronics and speakers, as did @millercarbon later with Townshend.  I tried using springs myself with some success under my electronics and under my two 160-pound subs and 170-pound speakers, both including their dedicated SA stands.  I studied what Townshend and Credo Audio were doing and damped the springs, but getting the size, travel, and spring constant properly sized for the weight supported and the isolation frequencies desired required a bit of trial and error.  As a result, I have a box of springs. 

I then switched to elastomeric materials (in essence another type of damped spring) and was pleased with the sound I was hearing when using products from Herbie's Audio Lab that are custom designed for different types and weights of electronic equipment and speakers, and are much less expensive than the spring solutions by Townshend or Credo.  The Herbie's dBNeutralizer material in their speaker support products is a harder elastomer with hardness (based on Shore A durometer - how hardness of an elastic material is measured) of 70 (quite a high number), which doesn't really compress much.

More recently, I have found other (much less costly) elastomeric products by Hudson Hi-Fi, that are available on Amazon.  Their products are made from platinum silicone.  BTW, the Herbie's products are also made from a silicone material.  I recently started using the Hudson Hi-Fi Silicone Hemisphere Bumpers under my main speakers and subs.  They conveniently provide the weight ranges supported by each sized hemisphere.  Since they are all a softer hardness of 20 (Shore A durometer), you need to go up in size to the larger products to support more weight.  I used their 2.5-inch size under the front of my speakers and the 2-inch size under the rear.   This worked out great since the weight of the drivers is in the front making the weight in the front of my stands heavier than in the back.  In addition, the speaker manufacturer recommends a slightly sloped front to back orientation so having slightly larger footers in the front was perfect.  You can simply stick the bumpers to the bottom of your equipment or speakers (which I have done with smaller power supplies and other ancillaries) but taking a cue from Herbie's, I attached the flat bottom of the bumpers to Magic Sliders and put the slider side down, which helps with sliding and positioning on carpet over concrete.  The result provides a much closer approximation to a damped spring than I had with the Herbie's products.  The speakers can actually move, as they could with the springs but they are damped so that when excited they become stationary after only a few oscillations.  They sound good so far under both my main speakers and under my subs (4 each at 2-inches).  Consider your options - YMMV.

The 10 Misconceptions article linked in a previous post was written by Norman Varney, who owns AV RoomService, Ltd., that sells a variety of vibration control products based on decoupling speakers and equipment. No great surprise Mr. Varney doesn’t support spiking speakers to the floor. Here, and here are a couple of other articles written by Mr. Varney.

Their Equipment Vibration Protectors (EVPs) are isolation feet that "de-couple vibration transmission by converting the mechanical energy into thermal energy." These appear to be basically Owens Corning 700 series fiberglass with either rubber or felt covering the top and bottom.  The Owens Corning board is an effective acoustic insulation.  I suspect the softer version could make an interesting DIY constrained layer equipment platform project. Their RoomDamp2 also looks interesting.

 

@audiopoint , i.e., Robert Maicks, is the long-time spokesperson (propriator?) of Live~Vibe Audio (that some may remember as Star-Sound Technologies), which sells primarily points (aka spikes), coupling discs, and Sistrum platforms to support speakers and other audio equipment. 

Cutting to the chase:

"Audio Points function as high-speed brass conductive gateways for resonance and unfavorable noise to flow out and away from the component or loudspeaker" 

"The high-speed exit of detrimental resonance caused by vibrations establishes greater “operational efficiency” within the component or loudspeaker per the laws of Coulomb friction and Coulomb damping."

Many audiophiles use and support their well-constructed products.  If encouraged, Robert will cheerfully go on ad-infinitum about the science behind their points or, you can look up his posts on this forum, and/or go to their website where you will find plenty to read.  You will also find an unwavering belief in their theory, without room for debate.  Mostly a case of Believe It or Not!

 

I tried to warn you guys, arguing is futile, so it is best to just... 

Believe It or Not.

Robert, I have been here a long time (since 99) and I have watched you verbosely try and convince others that your science and products are the clear winner, on thread after thread, in a hobby where there will never be an accepted clear winner.  Many here seem to like your products, so don't try so hard.  You are wearing people out. 

Craps sake Elliott, a whole $12.95!
You are going to send Robert off the edge!

@magnuman 

I went from using spikes to damped springs to elastomers to support my heavy (170 lb) speakers/stands.

I liked the sonic changes I heard after going from spikes to springs.  The platinum silicone elastomers I am using now behave and sound similar to the springs that I used previously.  Based on their oscillation behavior, the elastomers appear to be isolating my speakers down to a very low frequency.   The other things I like about the elastomers is how easy they were to set up and how they are ridiculously inexpensive compared to other "audiophile" footer options.