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Ten Misconceptions about Loudspeaker Spikes


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First, I never made any of those claims.  I do want to couple the speaker to the concrete below because it moves less than any other surface in our homes.  This is how every floor standing Vandersteen is designed and voiced.  I have qualified their exclusive use on tympanic floors by recommending a granite platform under them (spikes) if the resonant frequency of the floor is a problem.  The article is quite accurate except for acknowledging it may be a part of the design without any of these 10 claims.  I use them as a way to increase the apparent mass of the speaker in order to reduce movement of the speaker structure, no more, no less.  RV

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I had my old 2CE Signature IIs in my basement on the concrete slab.  They had Sound Anchor pucks under the spikes so I could move them around.  They were that way for months.  

One day, I decided to remove the pucks and let the spikes couple directly to the slab, because I hadn't moved the speakers and was satisfied with their position.  The increase in clarity floored me.   It should not be surprising to find that a steel spike to concrete allowed less deflection/motion of the speaker than a  1+ square inch of felt on the base of an aluminum puck.  When you consider the deflection magnification as you go up from the floor to the speaker centers, the actual speakers see a more compliant mount, and some of their energy goes into that spring.  That stiffness will be a function of frequency, based on the materials, and that energy gets released and smears the signal.   While this description may seem exaggerated relative to the motion involved, just experiment and listen. 

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  • 5 months later...

During my career at Chrysler Engineering, at one point, I was in the Exhaust Lab.

I used cotton string to isolate the exhaust pipes and muffler from the body, taking off the usual rubber isolators.

That was a common method to get rid of any input into the body during testing of prototypes.  

 

Just wondering if speakers hanging from cotton rope would be isolated in a similar manner. 

You'd need an aluminum structure, 2 ropes in the front, one in the rear to adjust tilt. Might be a good experiment

over at the Vandersteen Engineering facility.  Could make spikes, stands and granite bases obsolete!  😊

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On 4/2/2022 at 8:33 AM, Richard Vandersteen said:

The article is quite accurate except for acknowledging it may be a part of the design without any of these 10 claims.  I use them as a way to increase the apparent mass of the speaker in order to reduce movement of the speaker structure, no more, no less.  RV

Richard, you are a genius. "apparent mass".

"The floor, the ceiling, walls, furnishings can all be excited causing unwanted sound vibrations of resonances, buzzes and rattles. When the source of vibration (the loudspeaker) is isolated from the structure, only airborne sound waves from the speakers are heard. From an audiophile POV, dynamic range, low-level detail, tonality, spatiality, etc. are all improved. Everything becomes more articulate because the unwanted influences have been removed."

I add the stillpoints and get all those benefits.

But it's a bit thin. In this tradeoff, I'm taking all the above over perfect tonality. The bass is a little pudgy, without body, but equally the attack is clear because the sustain/decay is diminished.

But then you, Richard, go and drop the magic words, and I get thinking. The spikes don't drain or anything special. They provide "apparant mass".

So I disconnect with the stillpoints, according to the patent filing:

Vibration isolator

Jan 9, 2018 - Stillpoints LLC

In some embodiments, a vibration isolator comprises a housing having a base portion and a wall portion. A plurality of bearings are disposed within the housing. The bearings are arranged in a configuration comprising a plurality of layers. A first layer comprises a bearing and a second layer comprises a plurality of bearings. Each bearing in the second layer contacts the wall portion of the housing. Each bearing comprises a plurality of contact points in contact with another portion of the vibration isolator, and no two contact points of a bearing are diametrically opposed."

And from the article :

"Misconception 3 - Spikes Drain Energy

The idea is this: "The vibrations of the loudspeaker cabinet are deformed by its own resonances, which are transmitted back to the membrane of the loudspeaker and induce distortions.

So, rather than imprisoning the vibrations in the cabinet, we evacuate them out of the enclosure and direct them elsewhere. It is easier to evacuate the vibratory energy towards a heavy mass connected to the lighter enclosure."

I believe the concept is that of an inertia block. This is where the vibration source is in direct contact with a heavy (at least 3X the weight of the source), rigid block (usually concrete). The idea is that if you make contact with something much more massive, that the energy will be dissipated into it. Like a drain in a sink, the energy just disappears and does not return. Well, it doesn't work that way. As we've discussed, to isolate vibrations, the path must be broken, or the energy converted. In this situation, the energy will transfer into the block, and into whatever the block is resting on. Remember that vibrations travel both directions, and they can reflect. In the case of an actual inertia block system, they always have isolators at their base. There are many applications for inertia block isolation, however audio equipment is not one of them. For audio equipment, isolators alone are all that's needed."

Diametrically opposed = broken path.

So I got that going for me.

Then I IMG_20221003_085149.thumb.jpg.d7d2e59e7e823ac52905c4811abdbb86.jpg add back the apparent mass lost by "floating" the speakers.

Bada boom,  Bada bing. Best of both worlds. 

Just need to figure out the best weight, whether it's centered over the acoustical center of the speaker VS spiked center, how rigid I need to go, whether sound needs to exit the top,  ect ect. IMG_20221003_230606.thumb.jpg.54489d5414c35a83f0565eb3dce19baa.jpg

I think I have best liked so far a 16kg kettlebell placed on the back center of the top of speaker that doesn't inturrupt the up-center of the speaker.

I have measured to 1/50th of a lbs, 20lbs bags of aggregate and placed 20/40/60lbs on top of each speaker.

I think the center for adding weight is behind the acoustical center,

IMG_20221003_230546.thumb.jpg.24765c7e17748f07b6e470ebf498482d.jpg

Also, I believe I need ridigity, so I may keep an eye out for some heavier kettlebells on Kijiji. I'm not sure 20lbs bags of half inch aggregate are the best end game for on top of speakers. As a proof of concept,  they warrant moving forward with better alternatives.

 

 

 

 

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  • 3 months later...

After lots of experimenting, I havent completely narrowed it down, but seems about 30lbs on each speaker sounds about correct.

Stillpoints give a natural tri-plane resonance and clarity that are unbeatable. But a touch thin forwards/backwards. Really fills out with a nice solid attack when weight added.
 

On 4/2/2022 at 8:33 AM, Richard Vandersteen said:

I use them as a way to increase the apparent mass of the speaker in order to reduce movement of the speaker structure, no more, no less.  RV


Richard, is there such a thing as too little speaker structure movement, in general? Or with perfectly stiff frame/driver mounts would unlimited weight be a good start for a speaker design?

I'm assuming your speakers are tuned so that the movement of the speaker structure is put to good use at the correct frequency as best as possible (like the acoustic coupler 26-35hz).

I'm wondering if there is a 1/2 step backwards, full step forwards solution to be had by adding enough weight to drop the speaker resonance down to be hidden/blended at a lower frequency.

My dumb guess is maybe, but that the optimal place might be a full crossover/driver lower, which would be an 8x reduction in frequency, and an impossible mass like 8x 90lbs (720lbs) per 3a signature speaker.

Any thoughts are appreciated.

 

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2 hours ago, Ipspam said:

After lots of experimenting, I havent completely narrowed it down, but seems about 30lbs on each speaker sounds about correct.

Stillpoints give a natural tri-plane resonance and clarity that are unbeatable. But a touch thin forwards/backwards. Really fills out with a nice solid attack when weight added.
 


Richard, is there such a thing as too little speaker structure movement, in general? Or with perfectly stiff frame/driver mounts would unlimited weight be a good start for a speaker design?

I'm assuming your speakers are tuned so that the movement of the speaker structure is put to good use at the correct frequency as best as possible (like the acoustic coupler 26-35hz).

I'm wondering if there is a 1/2 step backwards, full step forwards solution to be had by adding enough weight to drop the speaker resonance down to be hidden/blended at a lower frequency.

My dumb guess is maybe, but that the optimal place might be a full crossover/driver lower, which would be an 8x reduction in frequency, and an impossible mass like 8x 90lbs (720lbs) per 3a signature speaker.

Any thoughts are appreciated.

 

In addition there are pate rubbing and beard-stroking opportunities inside many a speaker.
The motor being attached to the spider is a resonant system, and can and does resonate.
So either it is attached with some viscous absorbing gasket, or less commonly a metal bracket is used to hold the driver by motor.

In any case, I assume that the granite slab has felt feet or sorbethane, or something lossy on the bottom ?

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On 1/14/2023 at 1:23 PM, Ipspam said:

After lots of experimenting, I havent completely narrowed it down, but seems about 30lbs on each speaker sounds about correct.

Stillpoints give a natural tri-plane resonance and clarity that are unbeatable. But a touch thin forwards/backwards. Really fills out with a nice solid attack when weight added.
 


Richard, is there such a thing as too little speaker structure movement, in general? Or with perfectly stiff frame/driver mounts would unlimited weight be a good start for a speaker design?

I'm assuming your speakers are tuned so that the movement of the speaker structure is put to good use at the correct frequency as best as possible (like the acoustic coupler 26-35hz).

I'm wondering if there is a 1/2 step backwards, full step forwards solution to be had by adding enough weight to drop the speaker resonance down to be hidden/blended at a lower frequency.

My dumb guess is maybe, but that the optimal place might be a full crossover/driver lower, which would be an 8x reduction in frequency, and an impossible mass like 8x 90lbs (720lbs) per 3a signature speaker.

Any thoughts are appreciated.

 

Ideal would be no movement at all but that would require a concrete floor directly on earth.  RV

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On 4/2/2022 at 7:33 AM, Richard Vandersteen said:

First, I never made any of those claims.  I do want to couple the speaker to the concrete below because it moves less than any other surface in our homes.  This is how every floor standing Vandersteen is designed and voiced.  I have qualified their exclusive use on tympanic floors by recommending a granite platform under them (spikes) if the resonant frequency of the floor is a problem.  The article is quite accurate except for acknowledging it may be a part of the design without any of these 10 claims.  I use them as a way to increase the apparent mass of the speaker in order to reduce movement of the speaker structure, no more, no less.  RV

I think I need to investigate getting granite slabs. My floor is suspended vs slab (typical joist construction over lower level) with wood floors. Pretty lively. 

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On 1/14/2023 at 4:16 PM, Holmz said:

In addition there are pate rubbing and beard-stroking opportunities inside many a speaker.
The motor being attached to the spider is a resonant system, and can and does resonate.
So either it is attached with some viscous absorbing gasket, or less commonly a metal bracket is used to hold the driver by motor.

In any case, I assume that the granite slab has felt feet or sorbethane, or something lossy on the bottom ?

Use a piece of thin carpet or felt not sorbethane as it is like a spring.  RV

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1 hour ago, Richard Vandersteen said:

Use a piece of thin carpet or felt not sorbethane as it is like a spring.  RV

- And, it also stains.

2 hours ago, Patrick D said:

I think I need to investigate getting granite slabs. My floor is suspended vs slab (typical joist construction over lower level) with wood floors. Pretty lively.

If you own Treo's, I can point you to a pair of granite blocks on Amazon that fit well.

Bob

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4 hours ago, Patrick D said:

I think I need to investigate getting granite slabs. My floor is suspended vs slab (typical joist construction over lower level) with wood floors. Pretty lively. 

I went to my local granite counter shop and picked out a cut off piece of black with copper flecked granite they were about to toss.  All they charged me was for the chamfer i had them rout out on the top edge.  Looks perfect with my black (with copper metallic) paint.  The difference was noticeable without any break in, lol…hehe

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33 minutes ago, ctsooner said:

I went to my local granite counter shop and picked out a cut off piece of black with copper flecked granite they were about to toss.  All they charged me was for the chamfer i had them rout out on the top edge.  Looks perfect with my black (with copper metallic) paint.  The difference was noticeable without any break in, lol…hehe

Good idea! I'll get them for my 2CEs, and when I sell the 2's they can go with. Or maybe they would work with the Treos too.

You are using them with Treos or Quatros?

Edited by Patrick D
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22 minutes ago, ctsooner said:

Quatro’s.  Never get rid of them.  Just make sure the rake is corrected as they are now hitting the tweeter/ear’s in a different spot. 

Ah yes… I’ll measure the ear hight on the sofa to make sure it is high enough.

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On 1/14/2023 at 1:23 PM, Ipspam said:

After lots of experimenting, I havent completely narrowed it down, but seems about 30lbs on each speaker sounds about correct.

Stillpoints give a natural tri-plane resonance and clarity that are unbeatable. But a touch thin forwards/backwards. Really fills out with a nice solid attack when weight added.
 


Richard, is there such a thing as too little speaker structure movement, in general? Or with perfectly stiff frame/driver mounts would unlimited weight be a good start for a speaker design?

I'm assuming your speakers are tuned so that the movement of the speaker structure is put to good use at the correct frequency as best as possible (like the acoustic coupler 26-35hz).

I'm wondering if there is a 1/2 step backwards, full step forwards solution to be had by adding enough weight to drop the speaker resonance down to be hidden/blended at a lower frequency.

My dumb guess is maybe, but that the optimal place might be a full crossover/driver lower, which would be an 8x reduction in frequency, and an impossible mass like 8x 90lbs (720lbs) per 3a signature speaker.

Any thoughts are appreciated.

 

Speaker movement at any frequency should not be allowed!  The movement is caused by the air mass the woofer is trying to displace and the kinetic energy caused by the mass of the cone/voice coil.   There is no way to have this movement assist moving air as it is always after the fact and inverse in phase.  RV

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40 minutes ago, Richard Vandersteen said:

Speaker movement at any frequency should not be allowed!  The movement is caused by the air mass the woofer is trying to displace and the kinetic energy caused by the mass of the cone/voice coil.   There is no way to have this movement assist moving air as it is always after the fact and inverse in phase.  RV

OK - let’s call the axis that the speaker drives as being N/S (or is fore/aft better.)
The SPL of the cabinet will be proportional to acceleration * area. 
So a 2C or a Treo (minimum baffle) would have  a lot less area than say a DeVore O/9#.

The up/down and east/west should not be very affected by the cone forces/movement.
But I suppose that resonance could sneak into the floor if there were vibrations in those axes.

I would think that those spring pads would make more of a difference on a larger baffle enclosure.
But the floor resonance would be mitigated to an extent by the springs.

It seems like there are a few things going on here, and that they may be somewhat contradictory.

  • Spikes help the enclose not move fore/eft
  • Spikes coupled resonance into the floor.
  • Springs decouple the floor
  • Springs allow the enclosure to rock fore/aft (N/S)

It seems kind of confusing, and may also be speaker dependent?

Edited by Holmz
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