# Speaker isolation spikes



## Audiodreamer (Jan 11, 2009)

I Have a pair of low end Def Tech towers. The spikes that came with the speakers are not long enough to make contact with sub-floor due to thickness of carpet and pad. 

Although these speakers are the best speakers I have ever owned I do no they are not the best. Because I have heard better. I still need to isolate and level speakers.

Any recommendations without spending more than I did on the speakers?

Thanks Mike


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## SAC (Dec 3, 2009)

I wouldn't worry about it... Here's why...

Spikes, assuming they make proper contact with an underlying rigid substrate, do not mechanically decouple the speaker, they mechanically couple the speaker to an underlying substrate.

This can be theoretically advantageous is the base upon which they sit is mechanically inert and will not transmit and couple the energy to other complaint surfaces that may retransmit the energy either audibly or mechanically to other sensitive structures. Technically the benefit will be an improvement in the group delay or rate of change of phase - albeit on a very small scale.

This is typically a good option if the supporting surface is inert, such as with a concrete slab floor. 

Decoupling, on the other hand, isolates and prevents the mechanically coupling of two structures such that the energy is not efficiently transmitted from one structure to another, possibly being transmitted to another structure that may retransmit the energy audibly or mechanically to other structures. An excellent material for this purpose is Sorbothane, a visco-elastic material that effectively dissipates mechanical energy.

This can be important if the speakers are setting on a non-rigid surface such as a suspended wood floor.

As long as the speakers are not physically 'walking', their sitting on a carpet and pad surface that do not effectively couple the speaker to the floor is fine. 

Spikes in this case, provided they do not penetrate the carpet and pad to make contact with the rigid surface below the pad can be used as 'grippers' to simply help hold the speakers in place in the carpet without actually coupling the speakers to the underlying rigid substrate. In this case the speakers will be, for all intents and purposes, mechanically isolated.

Thus, the proper answer to which approach is of use is determined by the nature of the adjoining structure and by what, if any, problems are associated with the behavior of that structure.

I understand your desire to improve your system to the greatest degree possible, but don't start trying to find magical solutions in spikes, cables and the various miscellaneous accessories that capitalize on this desire without actually delivering much, if any, real benefit other than psychological.

May I suggest that if you want to actually become involved and to make a significant difference, that this can be most effectively accomplished by optimizing the acoustical interaction of the room and speaker. You might want to begin by reading Sound System Engineering by Davis and Patronis, especially the ~76 pages of chapters 4-8 in the 3rd ed. or 5-8 in the 2nd edition sufficient to understand the concepts of small acoustical space acoustics. Armed with a good understanding of the basics you can then utilize such tools as the freeware RoomEQWizard or the inexpensive but very powerful ARTA to measure and address the modal and specular issues that a very dominant impact upon the quality of the sound in the room. And in this way avoid wasting money on 'feel good' improvements and instead direct the money and effort toward real improvements.


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## I=V/R (May 25, 2011)

I had the same problem. I am currently strapped for cash, so what I did was drill a small hole in the center of nickels. I used the nickels like discs for the spikes to rest in. What I found it does is remove speaker from carpet and not couple to concrete. I am happy with my $0.40 solution!


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## robbo266317 (Sep 22, 2008)

I agree with what SAC said:-

As long as the spikes penetrate the carpet they will hold the speakers in position. 

He also said you should look at optimising your speaker placement to maximize your listening pleasure.

Cheers,
Bill


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## Audiodreamer (Jan 11, 2009)

So would I be better off eliminating the spikes? The real issue for me is not necessarily thinking that I am going to improve my sound quality, rather trying to keep my speakers from looking like leaning towers. Hence thinking that longer spikes would contact concrete therefore giving me the opportunity to keep my speakers straight and level.


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## Audiodreamer (Jan 11, 2009)

I have read a similar book. I do believe although not perfect yet that I do have my speakers set in the best position for one sweet spot.I have no room treatments or other devices to try and achieve best possible sound. Simply because this is my living room, not a dedicated listening room. I don't think my wife *you guys probably know* would like me very much.


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## robbo266317 (Sep 22, 2008)

I would leave the spikes even though they don't go fully through to the concrete.


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## mjcmt (Aug 30, 2010)

I've had the same issue w/ my Target Audio speaker stands. I've found the carpet does interfere w/ the spikes totally doing its job, but I'm too lazy to purchase longer ones. They can be had from Part Express and Madisound for cheap if you look up speaker spike on these web sites, but make sure you get the correct thread size.


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## Low-Q (Oct 11, 2009)

Audiodreamer said:


> I Have a pair of low end Def Tech towers. The spikes that came with the speakers are not long enough to make contact with sub-floor due to thickness of carpet and pad.
> 
> Although these speakers are the best speakers I have ever owned I do no they are not the best. Because I have heard better. I still need to isolate and level speakers.
> 
> ...


The best solution is not using spikes at all, but soft absorbing knobs under the speakers. This is regardless of the speaker construction and floor material. Any energy that is transfered to the enclosure must be terminated, and using spikes on concrete floor will only make mechanical reflections in the enclosure structure. Depending on the conditions, it will be a great sound improvement only by removing the spikes and replace it with soft knobs. It is even visible on a impedance measurement. You can clearly see the mechanical reflections in the enclosure structure affect the impedance in the speaker drivers when using spikes versus soft knobs. These reflections will often affect the speaker performance in a negative way.

I have been reading that it is important to let the speaker be as rigid as possible. Well, that is partially true. Because the diaphragm in a speaker driver will allways move relative to the enclosure, it will usually not affect the speaker output. However, rigidity is important to reduce mechanical transformation of sound into the floor. What I can conclude with is this:
Heavy rigid enclosure structure that is placed upon soft absorbing knobs will usually provide the most predictable and correct sound reproduction, or at least have the best potential to do so.

Beside this, I would recommend to acoustically disconnect the drivers from the enclosure. Drivers that is screwed directly into the structure will transfer great amout of energy into the structure which is turn will affect sound reproduction. If you manage to let the speaker driver rest on a soft material, so it isn't in direct contact with the enclosure (Like an engine is resting on rubber structures in a car), you will clearly hear that the midrange reproduction is much cleaner.

Br.

Vidar


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## lcaillo (May 2, 2006)

Has anyone measured differences with and without spikes? I have heard lots of discussions over the years of why spikes are useful or why they are not, but I do not recall any testing. This seems easy enough to do for anyone using REW. Any volunteers?


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## MikeBiker (Jan 3, 2010)

Audiodreamer said:


> So would I be better off eliminating the spikes? The real issue for me is not necessarily thinking that I am going to improve my sound quality, rather trying to keep my speakers from looking like leaning towers. Hence thinking that longer spikes would contact concrete therefore giving me the opportunity to keep my speakers straight and level.


You must have a nice thick pad and carpet. To keep your speakers level, you must get longer spikes to contact the underflooring so t hat the speakers are not loosely laying on the carpet.


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## mjcmt (Aug 30, 2010)

I've never tested, but the audible difference is obvious. Another tweak like platforms, cabling, etc. You may or may not the change. Another example is two cd players may test similar but sound vastly difference. I let my ears be the guide.


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## Low-Q (Oct 11, 2009)

lcaillo said:


> Has anyone measured differences with and without spikes? I have heard lots of discussions over the years of why spikes are useful or why they are not, but I do not recall any testing. This seems easy enough to do for anyone using REW. Any volunteers?


Does this post answer your question (The impedance measurement part): http://www.hometheatershack.com/forums/remotes-cables-accessories-tweaks/52177-speaker-isolation-spikes.html#post476700


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## g997 (Jan 13, 2012)

I just spent a few weeks trying coupled and decoupled Track Audio spikes on my speakers.

The floor is quarter sawed oak on top of a double layered sub floor. Speakers are Wilson Sasha's

Started with the decoupled versions in place of the factory spikes. 
The outcome was very mixed, mostly not good.
Focus, being able to define specific images and depth all diminished. Layering in the sound field also collapsed. Bass got lumpy and ill defined. All in all it turned my system into good background FM sound.
The Track spikes use Delrin and o rings to decouple. I always find Delrin to sound the same when used in an audio application..bad

Next up the coupled versions. I was hoping that these Track Audio spikes would be an improvement over the factory ones which are coupled also. So everything got better. Detail, bass definition, depth all improved. The only negative, some harshness coming thru. But, I'm thinking it's a more accurate representation of the source as it's only apparent on certain discs and to varying degrees. I guess I never realized it as much until it was gone. All in all a much nicer musical presentation.

Now back to the factory spikes. Just as good as the Track Audio spikes. Actually, I think they are better because the system sounds faster and lighter on it's feet so to speak.

So for me, decoupling my speakers didn't pan out

Regards..


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## Low-Q (Oct 11, 2009)

These Wilson Sasha speakers are quite rigid and heavy, aren't they?
I can read you have a pretty rigid and "dead" floor too. Nice to read such a detailed report of your findings. Thanks!

Vidar


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## illini_skn (Feb 5, 2012)

Another option is to get some stone or metal slabs (doesn't have to be granite but does have to heavy) and place the spiked speakers on top of the slabs, which then go on the carpet. Worked like a charm for me before we replaced the carpet with hardwood.


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## ISLAND1000 (May 2, 2007)

I add shotgun pellets wrapped in nylon stocking material to the inside of my speaker boxes for the added mass. It seems to add that tingling high frequency clarity I'm always looking for. You have to experiment with the correct amount of added mass.


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## Low-Q (Oct 11, 2009)

To enhance the midrange it helps to acoustically decouple the midrange unit from the enclosure. This way the motorsystem cannot transfer machanical midrange energy directly into the enclosure material. Ever tried to knock on an enclosure surface with the wedding ring on your finger? Try the same with a piece of whool between. Not the same sound, but much more quiet. The difference is chrystal clear even with the most rigid enclosire materials.
It might be required to redesign the crossover network in order to flatten the frequency response - it might happen that some frequencies originally was amplified by the enclosure structure.

Vidar


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## informel (Jun 21, 2011)

SAC said:


> You might want to begin by reading Sound System Engineering by Davis and Patronis, especially the ~76 pages of chapters 4-8 in the 3rd ed. or 5-8 in the 2nd edition sufficient to understand the concepts of small acoustical space acoustics. .


Your link point to ebay but with no reference to Davus and Patronis


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## ISLAND1000 (May 2, 2007)

Low-Q said:


> To enhance the midrange it helps to acoustically decouple the midrange unit from the enclosure. This way the motorsystem cannot transfer machanical midrange energy directly into the enclosure material. Ever tried to knock on an enclosure surface with the wedding ring on your finger? Try the same with a piece of whool between. Not the same sound, but much more quiet. The difference is chrystal clear even with the most rigid enclosire materials.
> It might be required to redesign the crossover network in order to flatten the frequency response - it might happen that some frequencies originally was amplified by the enclosure structure.
> 
> Vidar


Are you talking about a midrange unit with a moving cone? If the cone moves independently of the driver basket/frame, how will "acoustically decoupling" the motor system and basket/frame from the box keep the cone movement from exciting the box?


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