How shape/material of speaker footers impact their effectivness

[cjf]

Hello,

I've been poking around lately with the idea of how changing/altering the feet of my aluminum cabinet speakers might improve on or reduce their ability to work effectively in my room. I am trying to avoid the use of subjective sound quality related opinions in this post in an effort to better stay in line with this forums target purpose for existing but some mention of that will no doubt be inevitable just to make a point or better explain what I mean.

I've read various posts found on WBF and other places about Coupling/Decoupling..etc but am unclear on a few items. My speakers come with spikes that are permanently attached to their Outriggers. The manufacturer has been on record as saying that coupling and the use of their Spike is the way to go but I wonder if they have forgotten about the poor slobs like me with suspended wooden floors when they make this blanket recommendation. I've used that configuration in the past and it resulted in lots of excess bass boom and floor borne vibration in the room.

I've seen various products on the market that claim to have the ability to transform vibrational energy into Heat via the use of foam/sponge like materials that are sandwiched between two metal plates (an example would be Symposium Svelte Shelves). Its claimed that ideally the speaker should rest directly on these platforms without the use of Spikes or as an alternative a small round disk is placed between the speaker cabinet and the platform. Both of these techniques are said to provide a better pathway for vibration to follow due their much larger contact surface area compared to a Spike.

This brings me to some questions. From what I have seen almost all speaker feet or floor protector type devices are round/conelike in their shape. My assumption for the use of this common shape is that it may help more evenly distribute whatever vibration is being fed into them in a nice even 360deg pattern. Just a theory! But when it comes to a Spike we are talking about a tiny point which appears to instead attempt to create a perfect 90deg angle from it and the surface it sits on to try and drive the vibration itself directly thru whatever surface it sits on.

A few questions:

1. Is a Cone/Round shape better then any other shape in terms of vibrational energy evacuation?
2. Can a perfect Square Cube evacuate energy just as effectively as a round shape?
3. Is the material used in the make up of the footer more important then the shape itself?
4. If a Spike is placed into a square cube (maybe 1" on all sides) that has a single hole that passes all the way thru it that is big enough to accept at least half of the Spikes length which in turn alters the contact point of the Spike to now be much further up near the fat base of the cone like shape what could we expect the outcome to be in terms of effectiveness as a speaker footer? Just as good as the original tiny tip or not as good? (An example below)
5. What if the cube below is combined as explained in q#4 above with a Svelte shelf like platform? Do you think it will be more effective or less effective then the Spike on its own at lowering in room boom and floor borne vibration?

Some deep stuff no doubt but could be an interesting discussion nonetheless.

 

[amirm]

Good topic.

If I may give a side answer , boominess in the room has nothing to do with footers. It is a room characteristics.

I actually quite enjoy the coupling of speakers to the suspended wood floor as it provides great tactile feedback with deep bass.

So my question would be do you enjoy that deep vibration that is not heard but coupled to your body? If not then yes, we should get into what decouples it best.

 

[fas42]

Yes, good topic! My own experiences led me very quickly, some decades ago, to doing whatever it takes to make the speaker cabinet have as much effective mass as possible - which is why these ultra heavy, expensive speaker often win; the mass of the cabinet is doing a huge amount to get the sound right.

Which means, never have the speaker sitting free on some 'isolation' device - spikes, balls, whatever ... Either "glue" or strap the cabinet to the floor if that is massive, or if the floor is flimsy, bouncy, place an extremely heavy, dense platform on the surface, and lock the cabinet to that.

Result is, first of all, no boomy bass!! I have never had an issue with this, which is a good thing. because I hate that burbling sound, with a vengeance! So, extremely tight bass, and the rest of the sound sharpens up - of course, if the playback has distortion issues then these will become very obvious - and so one solution is to loosen up the speaker mounting ; goodbye awareness of distortion. hello, clouded reproduction ...

 

[cjf]

Hello Amirm,

I prefer the airborne vibrations to be felt more in the chest then in my feet. I would consider the ideal configuration to be a depleted uranium speaker cabinet that levitated in the air so that the only thing generating the movement of air in the room is the speaker driver. In this configuration I suspect one would feel it all in the chest..etc

 

[cjf]

Fas42, So it sounds like your favored approach would lean more towards increasing the contact patch of the speaker into a more dead or less resonate surface. At a high level this approach would be more inline with the example I gave in question #5 initially...correct?

 

[Fitzcaraldo215]

My opinion is that pointy cone feet were invented for a simple reason: to poke through carpet into the floor giving a sturdier footing. I do not think anyone has ever proven it sounded better, anywhere under any circumstances. But, from that simple idea, myriad myths exploded about better sound, and it grew to the need to place them under other equipment, as well. It also took off into various materials for pointy cones - steel, brass, aluminum, etc. each having their strong supporters as to why one material was better than another. Still no proof of that or even of the original pointy cones premise.

Then others chimed in with alternative claims about soft spongy feet or air bladders or wood blocks or ball bearings permitting horizontal excursions or entire expensive racks or stands, and so on. You name it.

There have been elapsed decades for the manufacturers of these "essential" audiophile improvements to provide some objective proof that they do anything at all. None has been forthcoming that I am aware of. Yet, the glossy magazines and audiophiles everywhere use them unquestioningly, upgrading from one idea to another, insisting it makes a worthwhile sonic difference under their conditions of sighted, uncontrolled listening.

Sorry to be so irreverent, and I am all in favor of nice, sufficiently sturdy placement of speakers and other equipment. But, like many things in audio, it is fundamentally bull in terms of improved sonics. This is audio jewelry and a waste of money. It relies on confirmation bias and the power of suggestion to make the sale, just like exotic cables and many other forms of snake oil.

Bottom line: you will find no answers in audio science or, likely, from this forum.

 

[RayDunzl]

My speakers have 3 spike/pointy screws, not cones. They poke through the carpet to concrete slab. Beyond levelling, or in my case, tilting, and solid footing, I don't expect or think I need anything else.

If I had a suspended floor, I might reconsider.

https://www.unitednuclear.com/​

 

[cjf]

My opinion is that pointy cone feet were invented for a simple reason: to poke through carpet into the floor giving a sturdier footing. I do not think anyone has ever proven it sounded better, anywhere under any circumstances. But, from that simple idea, myriad myths exploded about better sound, and it grew to the need to place them under other equipment, as well. It also took off into various materials for pointy cones - steel, brass, aluminum, etc. each having their strong supporters as to why one material was better than another. Still no proof of that or even of the original pointy cones premise.

Then others chimed in with alternative claims about soft spongy feet or air bladders or wood blocks or ball bearings permitting horizontal excursions or entire expensive racks or stands, and so on. You name it.

There have been elapsed decades for the manufacturers of these "essential" audiophile improvements to provide some objective proof that they do anything at all. None has been forthcoming that I am aware of. Yet, the glossy magazines and audiophiles everywhere use them unquestioningly, upgrading from one idea to another, insisting it makes a worthwhile sonic difference under their conditions of sighted, uncontrolled listening.

Sorry to be so irreverent, and I am all in favor of nice, sufficiently sturdy placement of speakers and other equipment. But, like many things in audio, it is fundamentally bull in terms of improved sonics. This is audio jewelry and a waste of money. It relies on confirmation bias and the power of suggestion to make the sale, just like exotic cables and many other forms of snake oil.

Bottom line: you will find no answers in audio science or, likely, from this forum.

Interesting thoughts, so would you say that you are a non believer in excess vibration within a speaker cabinet needing to be "drained" or that having excessive vibration within the listening room structure being detrimental to how both perform there job? I ask this ignoring anything to do with how either one or both may or may not effect sq perceptions.

If we look at this strictly from a science standpoint surely it cant be too hard to prove that after taking initial vibration measurements of a component then additional measurements of all its nearby supporting platforms then you place contraption A under the component and measure it all again that some change in vibration will indeed have taken place in one of these objects for better or worse.

I certainly don't want to place anything under the speakers that will result in worse performance and I also wouldn't be surprised if whatever the best approach is will also likely be the same one that sounds best subjectively to these ears

 

[amirm]

Question about your speakers. When you put your hand on the enclosure, do you feel much vibration?

 

[March Audio]

Hello,

I've been poking around lately with the idea of how changing/altering the feet of my aluminum cabinet speakers might improve on or reduce their ability to work effectively in my room. I am trying to avoid the use of subjective sound quality related opinions in this post in an effort to better stay in line with this forums target purpose for existing but some mention of that will no doubt be inevitable just to make a point or better explain what I mean.

I've read various posts found on WBF and other places about Coupling/Decoupling..etc but am unclear on a few items. My speakers come with spikes that are permanently attached to their Outriggers. The manufacturer has been on record as saying that coupling and the use of their Spike is the way to go but I wonder if they have forgotten about the poor slobs like me with suspended wooden floors when they make this blanket recommendation. I've used that configuration in the past and it resulted in lots of excess bass boom and floor borne vibration in the room.

I've seen various products on the market that claim to have the ability to transform vibrational energy into Heat via the use of foam/sponge like materials that are sandwiched between two metal plates (an example would be Symposium Svelte Shelves). Its claimed that ideally the speaker should rest directly on these platforms without the use of Spikes or as an alternative a small round disk is placed between the speaker cabinet and the platform. Both of these techniques are said to provide a better pathway for vibration to follow due their much larger contact surface area compared to a Spike.

This brings me to some questions. From what I have seen almost all speaker feet or floor protector type devices are round/conelike in their shape. My assumption for the use of this common shape is that it may help more evenly distribute whatever vibration is being fed into them in a nice even 360deg pattern. Just a theory! But when it comes to a Spike we are talking about a tiny point which appears to instead attempt to create a perfect 90deg angle from it and the surface it sits on to try and drive the vibration itself directly thru whatever surface it sits on.

A few questions:

1. Is a Cone/Round shape better then any other shape in terms of vibrational energy evacuation?
2. Can a perfect Square Cube evacuate energy just as effectively as a round shape?
3. Is the material used in the make up of the footer more important then the shape itself?
4. If a Spike is placed into a square cube (maybe 1" on all sides) that has a single hole that passes all the way thru it that is big enough to accept at least half of the Spikes length which in turn alters the contact point of the Spike to now be much further up near the fat base of the cone like shape what could we expect the outcome to be in terms of effectiveness as a speaker footer? Just as good as the original tiny tip or not as good? (An example below)
5. What if the cube below is combined as explained in q#4 above with a Svelte shelf like platform? Do you think it will be more effective or less effective then the Spike on its own at lowering in room boom and floor borne vibration?

Some deep stuff no doubt but could be an interesting discussion nonetheless.

I think first of all you need to establish what you think the problem is then work from there. This all seems a bit speculative. What are you really trying to achieve for what reason?

Just a few things first. Solid objects, spikes, balls do not isolate. A rigid coupling is just that. If you want to isolate vibration you require a compliant coupler of the correct durometer for the mass and frequency you want to control.

Objects dont behave like a single item WRT vibration. A simple example of this is a wine glass. Hold the base loosely in your hand and flick the bowl. It dings. Now firmly press it onto a concrete floor. Flick it. It stil goes ding. The bowl is doing its own thing. Its vibration does not get earthed, sunk or disapear into the ground.

So if your speaker box panels have resonances then placing them on any particular base or coupled in any particular way wont solve it. ( it will change the behaviour of the bottom panel).

If your suspended wooden floor is resonating and colouring the sound you need to test it and see where the resonant frequencies are. Being large they might be quite low. However it may not be the problem you think it is.

If you want to stop vibration excitation coming through mechanical coupling from the speaker you need to isolate it with a compliant material. You wont stop acoustic coupling from the sound pressure in the room so you again need to make sure the floor doesnt have any particular resonant frequencies (in the wrong place) The basic things you do to change the vibration behaviour of the object are change stiffness, mass and damping.

Basically its complicated . Unless you know what you want to achieve, why and have measurements to confirm what the issue is and validate the changes, you are going nowhere.

I would suspect that the general acoustics of the room are a far bigger player than speaker mount issues.

 

[fas42]

Fas42, So it sounds like your favored approach would lean more towards increasing the contact patch of the speaker into a more dead or less resonate surface. At a high level this approach would be more inline with the example I gave in question #5 initially...correct?

Possibly ... the principle, as I see it, is that the cabinet vibrates from the energy of the speakers working; from the air within being disturbed, and the frames of the drivers being firmly attached to surfaces of the cabinet. So, to me the ideal is that the cabinet doesn't vibrate, remains completely inert no matter what the drivers are doing - so the energy that's imparted to the body of the speaker needs to be damped, snubbed, or transferred to a much, much heavier body. If the cabinet were literally concreted into the earth this would be ideal - the earth absorbs all that vibrational energy. Stepping back from that, a compromise is to effectively attach much greater mass to the cabinet - just sitting the cabinet on top of spikes, etc, won't do that, because the cabinet is free to "bounce upward"; only its weight is useful in "holding it down".

I used this approach with every system I've played with - even the cheapest of cheap speakers sound vastly better, to me, doing this.

 

[Sal1950]

The easy, common sense answer to me is that a speaker should remain as still as possible, period. Whatever method that can keep cabinet movement from modulating the wavefront being produced by the drivers is the ultimate goal.
When folks start discussing cabinet resonances, it's JMO that a speaker should be designed to have the cabinet as non-resonate as possible within the bounds of build cost. If the designer is using the cabinet as a passive radiator rather than being inert, then all bets are off as I believe he's doing things ass backwards from the get-go.

 

[March Audio]

Fas, we have been through this before, it doesnt work like that. The speaker box is made of seperate elements WRT vibration. Concreting the base of the speaker into the ground may not do anything at all to stop the side panel vibrating.

The side panel has its own natural frequencies. To change its vibration chracteristics you need to change that panels mass, stiffness and damping.

 

[Thomas savage]

Iv tried all sorts under my vivids, can't say it changes the sound. Iv got them stuck down with...., blu tack

On bamboo plinths so I can move them about and raise them up about a inch or so.

 

[March Audio]

The easy, common sense answer to me is that a speaker should remain as still as possible, period. Whatever method that can keep cabinet movement from modulating the wavefront being produced by the drivers is the ultimate goal.
When folks start discussing cabinet resonances, it's JMO that a speaker should be designed to have the cabinet as non-resonate as possible within the bounds of build cost. If the designer is using the cabinet as a passive radiator rather than being inert, then all bets are off as I believe he's doing things ass backwards from the get-go.

Whilst that is intuitively correct you will always have a degree of panel vibration. The baffle the drivers are mounted in will still vibrate even if the box is concreted into the floor. Interesting test you can do is put a mic right in front of a tweeter and play say a 5 kHz tone amd look at it on an FFT. Then get the woofer to play a 200Hz tone at the same time. See the 200Hz side bands appear on the 5kHz signal

 

[fas42]

Fas, we have been through this before, it doesnt work like that. The speaker box is made of finite elements WRT vibration. Concreting the base of the speaker into the ground may not do anything at all to stop the side panel vibrating.

The side panel has its own natural frequencies. To change its vibration chracteristics you need to change that panels mass, stiffness and damping.

It's not base panel surfaces one worries about, it's the corners - the strongest, most rigid part of the cabinet - that are locked into position; the floor of the speaker is left free to do what it wants to.

Yes, the side panels may still vibrate, so an optimal solution will be to also render all these areas inert as possible by the measures you mentioned. But just doing what I describe makes such a difference I haven't bothered to take it further - good bye, small box speaker sound; good bye, sloppy bass.

 

[March Audio]

Fas it doesnt matter if the corners are locked into position, the other panels will still vibrate doing their own thing.

Next week I will measure a speaker baffle panels vibration, rigidly bolted to a stand and with squidgy sorbothane pads and we shall see how it changes

 

[cjf]

Question about your speakers. When you put your hand on the enclosure, do you feel much vibration?

Almost none that I can tell unless I am playing near 100db or so and even then its not very noticeable to the touch

 

[Sal1950]

Almost none that I can tell unless I am playing near 100db or so and even then its not very noticeable to the touch

The ole knuckle rap test is still a good one. Knock your knuckles on various parts of the enclosure and see how much it produces a resonate sound or something more akin to a cement block.

 

[cjf]

I think first of all you need to establish what you think the problem is then work from there. This all seems a bit speculative. What are you really trying to achieve for what reason?

Just a few things first. Solid objects, spikes, balls do not isolate. A rigid coupling is just that. If you want to isolate vibration you require a compliant coupler of the correct durometer for the mass and frequency you want to control.

Objects dont behave like a single item WRT vibration. A simple example of this is a wine glass. Hold the base loosely in your hand and flick the bowl. It dings. Now firmly press it onto a concrete floor. Flick it. It stil goes ding. The bowl is doing its own thing. Its vibration does not get earthed, sunk or disapear into the ground.

So if your speaker box panels have resonances then placing them on any particular base or coupled in any particular way wont solve it. ( it will change the behaviour of the bottom panel).

If your suspended wooden floor is resonating and colouring the sound you need to test it and see where the resonant frequencies are. Being large they might be quite low. However it may not be the problem you think it is.

If you want to stop vibration excitation coming through mechanical coupling from the speaker you need to isolate it with a compliant material. You wont stop acoustic coupling from the sound pressure in the room so you again need to make sure the floor doesnt have any particular resonant frequencies (in the wrong place) The basic things you do to change the vibration behaviour of the object are change stiffness, mass and damping.sing

Basically its complicated . Unless you know what you want to achieve, why and have measurements to confirm what the issue is and validate the changes, you are going nowhere.

I would suspect that the general acoustics of the room are a far bigger player than speaker mount issues.

Ive taken measurements of the rooms acoustics using XTZ Room Analyzer and there was 1 bump at 39hz or so that was cured with a -3.5db cut worth of PEQ and another bump at 168hz or so that also only required a small cut of PEQ

My current footers are a combination of the factory Spikes and a set of Herbies Audio Lab Titanium Decoupling Gliders. Thus far this combo appears to have reduced bass boom/rumble in the room and to a greater extent reduced the vibration felt thru your feet when sitting in the room.

I thought I explained my intention of the post fairly clearly but to recap, I am wondering if an even better approach exists that would achieve more of the same results that I found when slightly Decoupling my speaker and how the shape and material used in the footer/footers/platforms ...etc can change its effectiveness to work as either a coupling or decoupling device.