Speaker Spike Philosophy


This is a learning exercise for me.

I am a mechanics practitioner by training and by occupation, so I understand Newton’s Laws and structural mechanics and have a fairly effective BS-detector.

THE FOLLOWING THINGS PUZZLE ME, and I would be glad to hear from those who believe they understand so long as the responses are based on your actual experience or on sound mechanical arguments (or are labeled as conjecture). These are independent questions/musings, so feel free to weigh in on whichever ones you want, but please list the number(s) to which you are responding:

  1. Everything I have read recently ("Ask Richard" (Vandersteen) from 15 Feb, 2020, for instance) seems to indicate that the reason for speaker spikes is to hold the speaker fixed against movement induced by the drivers. I have seen in the past other explanations, most employing some use of the term "isolation" implying that they decouple the speaker (from what?) Evidently the "what?" is a floor that is fixed and not moving (let’s assume concrete slab foundation). So to decouple the speaker from the floor, which is fixed, is to . . . allow it to move (or not) as it wishes, (presumably in response to its drivers). These two objectives, "fixity" and "isolation" appear to me to be diametrically opposed to one another. Is the supposed function of spikes to couple the speaker to "fixed ground" so they don’t move, or is it to provide mechanical isolation so that they can move (which I do not think spikes actually do)? Or, is it to somehow provide some sort of "acoustic isolation" having to do with having some free space under the speaker? Regarding the mechanical isolation idea, I saw a treatment of this here: https://ledgernote.com/blog/q-and-a/speaker-spikes/ that seemed plausible until I got to the sentence, "The tip of a sphere or cone is so tiny that no vibration with a long waveform and high amplitude can pass through it." If you have a spike that is dug into a floor, I believe it will be capable of passing exactly this type of waveform. I also was skeptical of the author’s distinction between *speaker stand* spikes (meant to couple) and *speaker* spikes (meant to isolate/decouple, flying in the face of Richard Vandersteen’s explanation). Perhaps I am missing something, but my BS-detector was starting to resonate.
  2. Spikes on the bottoms of stands that support bookshelf speakers. The spikes may keep the the base of the stand quite still, but the primary mode of motion of such speakers in the plane of driver motion will be to rock forward and backward, pivoting about the base of the stand, and the spikes will do nothing about this that is not already done by the stand base without spikes. I have a hard time seeing these spikes as providing any value other than, if used on carpet, to get down to the floor beneath and add real stability to an otherwise unstable arrangement. (This is not a sound quality issue, but a serviceability and safety issue, especially if little ones are about.)
  3. I have a hard time believing that massive floor standers made of thick MDF/HDF/etc. and heavy magnets can be pushed around a meaningful amount by any speaker driver, spikes or no. (Only Rigid-body modes are in view here--I am not talking about cabinet flexing modes, which spikes will do nothing about) "It’s a simple question of weight (mass) ratios." (a la Holy Grail) "An 8-ounce speaker cone cannot push around a 100/200-lb speaker" (by a meaningful amount, and yes, I know that the air pressure loading on the cone comes into play as well; I stand by my skepticism). And I am skeptical that the amount of pushing around that does occur will be affected meaningfully by spikes or lack thereof. Furthermore, for tower speakers, there are overturning modes of motion (rocking) created by the driver forces that are not at all affected by the presence of spikes (similar to Item 1 above).
  4. Let’s assume I am wrong (happens all the time), and the speaker does need to be held in place. The use of feet that protect hardwood floors from spikes (Linn Skeets, etc.) seems counterproductive toward this end. If the point of spikes is to anchor the speaker laterally (they certainly do not do so vertically), then putting something under the spikes that keep the spikes from digging in (i.e., doing their supposed job) appears to defeat the whole value proposition of spikes in the first place. I have been told how much easier it is to position speakers on hardwood floors with the Skeets in place, because the speakers can be moved much more easily. I was thinking to myself, "yes, this is self-evident, and you have just taken away any benefit of the spikes unless you remove the Skeets once the speakers are located."
  5. I am making new, thick, hard-rock maple bases for my AV 5140s (lovely speakers in every sense), and I will probably bolt them to the bottom of the speakers using the female threaded inserts already provided on the bottoms of the speakers, and I will probably put threaded inserts into the bottom of my bases so they can be used with the Linn-provided spikes, and I have already ordered Skeets (they were a not even a blip on the radar compared to the Akurate Exaktbox-i and Akurate Hub that were part of the same order), and I will end up doing whatever sounds best to me. Still, I am curious about the mechanics of it all...Interested to hear informed, reasoned, and reasonable responses.
linnvolk
I run the Gaia footers with very good affect under my ATC 40 actives.  I just followed through this morning with a menagerie of allen wrenches and star pieces to tighten up the driver component attachments to the cabinets.  I give credit to Tom, proprietor of Big Ear Stereo in Tempe, AZ for this suggestion.  

To my amazement several were less than tight.  And as one might surmise, everything just got better.  Uncontrolled vibration is found everywhere.

The creative questions presented by the OP are not capable of two sentence explanations. I attempted to keep more of the interesting facts and opinions in full view asking for your patience involving the length of read.

To linnvolk, in reply to your original post:

Generic Spikes are the problem!

Line item 1: Spikes cannot be defined or grouped into a single topic as no two designs are manufactured the same nor contain the same material-science or shape, therefore will not function in the same manner. This is true for spheres and springs and any other footer materials used in audio. Some cost a couple dollars where others are priced in the hundreds so which one should be used as the principal focus for topic discussion?

Disclaimer: I represent a thirty-two-year-old spike design that has earned a reputation in High-End Audio for delivering performance managing the musical characteristics known as attack, sustain and decays. We also manufacture platforms for floor standing speakers.

There are a lot of opinions focused on eliminating vibration on this forum. They are all based on theorems. In fact, “all methods of vibration management” are based on theorems, so it is easy to see that most listeners have a favorite of their own or have created a theory for themselves and that is a good thing as this is how Industry grows.


The only thing that all spikes have in common is they ‘mechanically ground’ a device to the greater energy sink in the environment. A spike can be defined as a mechanical resonance conductive conduit. An energy sink can be defined as the greater mass - of a floor, wall or room structure or earth’s ground itself.

Physics dictates all energy seeks earth’s ground and will transfer there via the path of least resistance.

In audio, spikes deliver a wide variety of speeds of resonance energy transfer which greatly affects the frequencies of the device being mechanically grounded. The material used to make spikes, their mass and body shapes are paramount to the overall function and sonic result of a spike.

Driver and chassis movement:

In my opinion, speaker cone movement related to chassis movement is a widening gate for arguments and subjectivity. There is no “live test” for speaker dispersion, meaning a driver could be firing a ninety-degree vertical spread on the left side and a sixty-degree horizontal spread on the right and no way to prove otherwise in a live dynamic environment.

 The first response to that statement is the anechoic test. Anechoic is a vacuum environment designed to tear away and absorb all energy including vibration, resonance and the laminar flows of energy seeking earth’s ground. We take computer generated readings and images to “show” the drivers are firing in the round then end up placing the speaker into a “live environment” where the laws of gravity, motion and Coulomb’s friction are ever present disrupting the anechoic test results. Then again, data is important so any type of test benefits education.

Speaker movement and chassis movement are minimalist concerns when the speaker system is mechanically grounded. In all my days of listening as a sound engineer and commercial sound consultant to the music lover and avid audiophile, there was never a time where I have been able to blame speaker cone movement related to chassis movement as a negative factor when encountering poorer sound quality. Or maybe I cannot tell or do not know if infinitesimal movement is audible.

My focus is audibility. Inaudibility delivers more questions and makes things more difficult to prove although inaudible noise plays a factor in the overall system sound, sound-staging, pressure levels and room sonic.


I wish audio companies could afford or would desire to establish third party testing methodologies backed with written opinions by our peers, hence quantifying the results. The larger more financially outfitted companies obviously avoid that type of research and would rather spend their dollars on marketing and product reviews. I also believe audio is too ‘humanly subjective’ for most sciences and/or third-party options.

We were involved in third party testing using temperature as our control factor. In our case mechanical grounding not only reduces noise but heat as well. Temperature reduction is more attractive to science in comparison to sound reproduction. Covid put a long delay on that project.

 

Line item 2: What most listeners and Industry reviewers and speaker designers fail to realize is the magnitude of sound quality that is missing due to the physical speaker-to-stand-to-floor relationship. 

A speaker stand plays the ultimate role in the overall sound performance of any compact monitor. The method in which the speaker is placed or mounted to the stand is extremely important as well. Ten thousand dollars spent on a pair of speakers with a six or seven-hundred dollar set of stands does not make for the best sonic performance from your financial investment.

The majority of speaker-stands in today’s marketplace lacks engineering and purpose other than they are a place to set your speaker on top. Too many variables one of which is my pet peeve… fill the legs with what kind of material and how much fill do I use? You might think the engineers in charge of the design would have done a lot of listening tests and figured that one out by now.

As for the lifestyle issues involving stability and children, we must first come up with a great stand then adapt a secure universal mounting system to hold the speaker without changing the sonic character of the speaker system.


Line item 3: Our platforms contain spikes and are designed to vibrate which is a form of movement. This motion is absolute minimalist. The artifacts caused by motion that a laser might determine are a moot point in comparison to using vibration as a tool to improve the physical operational efficiency of the device.


Increased component operational efficiency is attainable provided the mechanical grounding plane (the platform) transfers resonance at or as close to as possible, the speed of which resonance is being formed.  


The methodology of resonance transfer also works with electronics as these platforms are based on physics, material science and geometry. It does not matter what is placed on them (speakers, electronics, power distribution, compressors, fan motors, etc.) as the design is engineered for function. In addition, this system allows for weight tolerances in the thousands of pounds eliminating those issues.

In music reproduction, everything vibrates (movement) and has high-speed relationships beginning with the throat or musical instrument to the microphone diaphragm to the recording drives to the pre/post-production equipment to the structural environment and finally the human eardrum itself. Mechanical grounding is designed for rapid resonance energy transfer processes hence the timing relationship is formed.

 Vibrations create the REAL PROBLEM and that is RESONANCE.

Resonance is caused by many vibrations where amplitudes of resonance clog all signal pathways – mechanical, electro-mechanical and acoustic. The problem is those initial vibrations contain the dynamics and harmonic layers we seek to hear so one must capture those highly favorable features and avoid resonance buildup and in real time.

How does one manage resonance? Our preferred methodology is to transfer the resonance to the greater sink or mass in the environment.

This is where the isolation group has difficulty explaining their theories as isolation techniques hold resonance within the component or speaker system establishing operational inefficiencies.

Resonance without a rapid evacuation gateway will build and cling to and propagate on all smooth surfaces from transistors to large speaker chassis establishing operational inefficiencies. In essence, the equipment becomes a resonance capacitor – per the Laws of Coulomb.

The difference between a highly effective isolation system and resonance transfer system of near equal financial value is extremely audible and can be blind tested employing multiple listeners. Both isolation and transfer systems provide function, but the sonic results are quite different.


Line item 4 I do not want to stop your construction experiment using maple foundations but will inform you what to expect from this design approach and outcome.

Wood vibrates and establishes a lot of additional audible frequencies. These frequencies will influence everything in your system’s performance from electronics to acoustics. Proof of wood sonics are discussed many times on this forum. For years you read particle board sounds OK, hardened maple sounds better than butcher block, exotic hardwood species sound even better, etc. 

Wood also remains in a constant state of change and movement due to humidity factors so your audible point of sonic reference may also change daily along with the sonics wood produces regardless of mass or thickness.

Bolting the wood sections directly to your speaker will marry the plinth to the chassis so they will react as a single unit. You will increase the chassis mass and therefore alter the sound of your speaker – guaranteed. You may like or dislike the change, but the original speaker designer usually ends up becoming the unhappiest person involved in this experiment.

Then there is the mechanical grounding process where the “spikes” will control the result of the experiment. A poorly designed spike equals poorer performance and that we can attest to after working thirty years in the vibration management field.


A form of acoustic coupling is placing a speaker directly on a floor without separation of any kind between the two planes. The speaker now assumes the floor mass as being part of its design whereas the woofer/s generally overextends to compensate for the added mass. In the case of using a carpet membrane between the two, carpeting generally has rubber or foam in the mix where these primary adsorbent materials greatly limit the speaker’s dynamics and sound quality.

Acoustic coupling is not recommended by hi-fi speaker manufacturers as it results in sonic degradation. The industry needed an answer to this problem so early on, back in the sixties, the easiest and most affordable fix or add on accessory became the nail head spike or rubber footer. Both parts limit sound quality but still remain extremely affordable!

Years ago, prior to flying and mechanical grounding commercial sound systems to the ceiling grids, we stacked the speaker cabinets on the floor or stage so the ports would be parallel stacked or positioned side by side each other hence increasing the sonic output by 1.5dB. The coupled ports reinforced the air pressure exiting the system. This too was referred to as acoustic coupling.

Regards to surface protection discs, discs machined of metal, wood or any material lacking geometry degrades spike performance. We have spent years listening, prototyping and listening again to establish a highly functional Coupling Disc. The design was created to function specifically with our products but is known to increase the sonic of others. I cannot and will not attest to anything other than performances related to our specific products. Coupling Discs appear to be simplistic in cosmetic look but there is more engineering and time spent on development than most of our spike designs. The geometry is used for speed and time matching resonance flows from the spike or platform and energy distribution across the flooring surface.


Too much emphasis is placed on simplistic two-dollar parts that literally drive “High-End Audio” conversations, theorem evaluations and product comparisons in today’s modern market. Think about it?


Thank you for your time,

Robert

Disclaimer #2: This information is not written to increase sales nor are we shilling this site for business purposes despite some members consistently analyzing my participation as being of an advertising nature.

It is most difficult to provide information on a new technical approach opposite that of long believed old school methodologies when the products themselves become the determining factual evidence of proof and function.



Spikes only detract from the potential of a well built and designed speakers performance. Your goal is to decouple the speakers from the acoustics of the room, so you are listening to the drivers only as far as possible. The best way to do that is to use Norm Varney’s (AV Room Service) EVP decouplers. Very well priced when compared to the result. The EVP decouple your speakers from the room. Adding the EVP units under my speakers was one of the best bang for the buck upgrades if you are looking for a system that portrays the original recording the correct timbre and dynamics of a recording. Sharpened the mid bass all the way down to the lowest octaves. My system is capable of imaging to a much lower frequency with the EVP’s. Simply amazing

Has anyone else considered that the area of the driver creating the sound pressure wave also meets with resistance from the air it's moving, both inside and outside of the enclosure (assuming it is used in such a fashion).
Therefore it's not just the moving mass, it's also the back pressure from air resistance that can be taken into account??

Regardless, I have not heard speakers sound better than by effective decoupling in union with a tuned mass damping.

Unfortunately it is an economic compromise between mass and cost of logistics to ship and store loudspeakers. Mass is a great way to dampen, however mechanical engineering has evolved to the point where seismic devices are proven to be more effective, than trying to rigidly maintain integrity.

I do understand the skepticism to move away from traditional methods of loudspeaker mounting, however, having been exposed to newer technologies, there simply is no going back for me.
Has anyone else considered that the area of the driver creating the sound pressure wave also meets with resistance from the air it's moving, both inside and outside of the enclosure (assuming it is used in such a fashion).
@rixthetrick, yes.  See OP Item 3.