Coupling vs Decoupling


I’m new to this forum and have been doing much reading. I’m aware working with the room and equipment can produce dramatic changes in sound. One topic I’m lost with is coupling vs decoupling. When, where and how to apply each method to produce the best outcome?  

My current system is KEF R900 towers with matching center, R600C and surrounds, R300 and a pair of JL E112 subs flanking a Sony A1E TV.  The room is a bonus room approx 24’ x 14’ with all centered on the 14’ wall. 

Currently the towers are equipped with spiked plinths and subs sit directly on the carpet with their OE feet.  Any feedback about how to best manage acoustic vibrations and when/where to apply coupling or decoupling methods is greatly appreciated. 
jdeickhoff
A couple questions.
1.  What type of floor do you have in your listening room?
2.  What is your gear on?  Metal rack, wood rack or?  Is the rack or shelf spiked?

This is a great thread and has been discussed here before.  After decades of coupling, I tried decoupling, and in my room, with my gear, there is no going back.  The answers to the questions above will help us discuss your specific needs.
Here is a clip from the RMAF 2018 showing 2 pairs of speakers. Listen to the difference between one that is isolated and one that isn't.
Link is broken but if you go to the PS audio YouTube site you can see it
Generally speaking, a combination of coupling and decoupling achieves the best results. Example, to decouple/isolate a component use mass-on-spring technique. Then use very hard cones or spikes to couple the component to the iso stand AND to couple the stand itself to the floor or rack. This coupling allows residual vibration to exit the iso system pronto. Problem solved!
I appreciate the responses so far. 

@hifiman5 - the floor is a second story carpeted wood floor in a bonus room above the garage. The TV and components sit directly on a wood console, that is a leftover from pre-system days. Perhaps this is a great reason to upgrade!

@blueranger - thank you for the video. I’m very surprised the difference it made, even viewing from my iPad. I have looked at IsoAcoustics products recently. I’m curious which products and applications could produce best results. Do you have any personal experience with them?

@geoffkait - the idea of a combination to produce ideal results makes sense and is intriguing. Do you have personal experience with a product you’d recommend?
Gary Koh wrote this a while ago- may help your general understanding of the principles: [url]http://www.kosmic.us/Genesis%20Loudspeaker%20Coupling%20&%20Decoupling.pdf[/url]

@geoffkait - the idea of a combination to produce ideal results makes sense and is intriguing. Do you have personal experience with a product you’d recommend?

There is much to choose from for audiophiles these days in terms of isolation products. It all comes down to budget, the weight of the item to be isolated, and location of the item to be isolated, e.g., on the floor or on a rack. You could search for “audio vibration isolation devices” to get an idea of what’s out there.
The trouble with the Gary Koh article is that he didn’t consider mass on spring technology when discussing coupling vs decoupling. He only addressed viscoelastic “isolation” which is not really in the same ballpark. Mass on spring isolation for speakers happens to be a hot topic these days with at least a few Mass on Spring solutions available to audiophiles, including those from your humble scribe. Viscoelastic material is usually found in constrained layer damping solutions, which can be incorporated into mass on spring designs if desired. Kind of depends on what you’re trying to accomplish and how far you want to go.
@geoffkait - fair comment. I offered it not as a complete set of solutions but a starting point to understand the differences. Spring thing is good here (MinusK), at least under my turntable (~238 lbs with plinth).
I have my OHM 5000's on a homemade isolation stand. 4 aluminum cones with 2 granite slabs sandwiched with rubber and cork for dampening. I built a wood cradle around it so the speakers would be less likely to roll off. I have wood floors covered with carpet. 
jdeickhoff
the floor is a second story carpeted wood floor in a bonus room above the garage. The TV and components sit directly on a wood console
Always de-couple your speakers and equipment from a wooden floor even if it's carpeted, unless you want the floor to act as a sound board and ruin your bass.

Cement slab floor you can couple to.

Cheers George
@georgehifi  Agree with you about wood floors.  And coupling to a concrete slab floor can yield fine results... but, when this issue came up a couple years ago, I decided to decouple my main speakers and subwoofers and what I hear from that is greater clarity through the entire frequency range.

Why?  With decoupling, the energy from my speakers is dissipating across the carpeted floor rather than being transmitted into the slab underneath and then reflected back into my equipment rack and speakers causing a slight smearing and loss of detail to the sound.  It was quite definitive and after experimenting back and forth there is no going back to coupling for me.

The bonus benefit to the rest of the family is that my basement listening room is not rattling the upstairs when heavy bass is present in the music!

Thank you all for your response and input.  I've just begun the online search to learn of all the available products and options.  I'm interested to learn more about IsoAcoustic and Townshend platforms and pods.  Does anyone have experience or feedback about these companies or products?  Would either of them be a good option for my KEFs and JLs?

http://www.isoacoustics.com/gaia-series/

http://www.isoacoustics.com/orea-bordeaux/

http://www.townshendaudio.com/hi-fi-home-cinema-equipment-vibration-isolation/hi-fi-home-cinema-vibr...

http://www.townshendaudio.com/hi-fi-home-cinema-equipment-vibration-isolation/

Thank you for your time and input.

@geoffkait  - Mass on spring isolation for speakers happens to be a hot topic these days with at least a few Mass on Spring solutions available to audiophiles, including those from your humble scribe.


"From your humble scribe"....... Can you pleae elaborate?  I am very interested to see and learn more.



@jdeickhoff, to see and learn more about mass-on-spring isolation, go to You Tube and do a search for the Townshend Audio Seismic Pod video, on which that product is explained and demonstrated.
I sell two types of springs, one type for lightweight and moderate weight components and the other for moderately heavy and very heavy compondnts. See Machina Dynamica’s Page on vibration isolation at,

http://machinadynamica.com/machina25.htm

Geoff Kait
Machina Dynamica

We recommend spending time on the phone with various manufacturers, knowledgeable dealers and such if you wish to learn more as there are no third party laboratory tested performance validations known at this point in time leaving only opinions regarding coupling and decoupling techniques in audio.

The most important part of any vibration management formula is realizing there are thousands of variables with another few thousand coupling and decoupling methodologies used in audio. Add to that if you elect to combine these two directly opposite theorems, expect to add on another infinite amount of possibilities to the previous order. Then the decision on what choice of products to compare that matches your budget for evaluation processes. The only people who say resonance caused from vibration is not that difficult to understand or manage are the ones representing vibration control products in need of a quick sale.

Vibration management is not a proven science by any means and can be argued without end.


This we do know and is easily proven:

Equipment foundations define the end results related to the musical performance of any sound system. The racking support system will also determine the sonic results attained from coupling or decoupling speakers and components. The rack can be a blessing or a fault at the outset and could easily be the defining factor governing your wallet over time so if you own a poor to average functioning racking system and/or speaker plinths or monitor stands, you may never hear how good the electronics and speakers you already own actually sound.

Equipment racks influence the sonic of every piece of equipment you purchase regardless of the room design, flooring type, electronics selection, loudspeakers, coupling/decoupling accessories, cable products, etc.

The equipment rack design functionality determines the level of component operational efficiency. Unfortunately, for most, the equipment rack and speaker supports are deemed a very low consideration and/or minimalist-priority as equipment selections take place. IMO - Big Mistake #1.

The first question should be; does your equipment rack direct couple or decouple resonance build up or does your rack play a different type of functional role in vibration management or does the rack look nice, feels heavy and is rigid? Most do not know if their racking is highly functional for vibration management since they may have never compared it to another brand or materials type. 

Every rack manufacturer in audio says their version is the best at isolation whereas isolation is but only one concept in design. There are a lot of misbeliefs in the marketplace; for example did you know solid wood racks do not isolate resonance? At the very least, there are ways to step-up the performance of any racking system, regardless of build and materials as one should really explore those possibilities as well.


The reference to the isolation speaker video at Rocky Mountain (link posted above) where a company compares a few hundred dollars ($ 400.00+) worth of speaker “decoupling” support products to just four dollars ($ 4.00) worth of steel nailhead spikes “coupling” the speaker to the flooring; is that really a fair comparison between the two techniques? IMO - Definitely Not!

There are videos where people are stomping on floors putting up thousands of dollars worth of an isolation product (decoupling) against and dare we say it again, $4.00 worth of speaker spikes (coupling). The results prove nothing whatsoever other than hundreds or thousands of dollars always beats four. These are not comparative tests but more a demonstration in order to sell more product. Never compare coupling to decoupling without some type of fairness towards each individual product cost or you will be marketed out of your money for sure.


Why do so many audiophiles match the term “coupling” to generic spikes or cheap cones? There are thousands of various types of spikes and coupling devices available and they all sound and perform totally independent of each other. No two products sound nearly the same. Should we match up the term “decoupling” to a $4.00 tire inner tube, spring or a furniture moving coaster and compare them to an extremely well engineered coupling product? Guaranteed coupling wins!


Our company is about to release an Industry First new product and category in all of audio. We are presenting an engineered mechanically grounded structural sound environment. The equipment and loudspeakers are coupled to coupling racks, the structural walls; floor and ceiling grids are also direct coupled to earth’s ground along with all AC distribution, cabling and networks. There is no need for digital room correction or add-on acoustic control products as volume does not overload, over damp or reflect surface energy hence there is no slap echo or any known acoustic issues within this environment. The wall surfaces are smooth without anything hanging or attached to them in order to satisfy any cosmetic objections. The sound experience deserves an audition as proof in performance.  

If you listen inside this product, guaranteed you will become a supportive voice for “coupling”. But again, is this a fair comparison because a “decoupled” sound room is impossible to build?


I’m not here to argue pro or against the two methodologies or get tangled up in personality conflicts. We represent a group of professionals who devoted their livelihoods to understanding sound and resonance management.

Our advice is to call on manufacturers, listen to their pitch and have a conversation detailing the methods, technical discoveries, techniques and products as that is the only realistic way to gather knowledge in forming your own opinion or testing protocol.


The bottom line - finer companies who know their product’s value and performance capabilities always offer financial return guarantees whether you spend $10.00 or $10,000.00 and that business model definitely assists your discovery process. These few companies offer trade up programs so you do not lose your capital investment along the way. They also provide education and that is where your time involvement really pays off.

A manufacturer’s opinion,

Robert

Star Sound



Thank you audiopoint.  That’s a lot to unpack. I’m intrigued by your product and look forward to hearing more. 
I’ve taken your advice and reached out to KEF, IsoAcoustics, Townshend and Stillpoints directly. I’m eagerly looking forward to their responses.