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Speaker De-coupling

Siwel

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I decided to finally get rid of all the various mechanical buzzes and noises in my room. I ran tone at various frequencies between 20Hz and 100 Hz and just followed my ears to the various sources of mechanical noise in the room. This included framed pictures, a loose access panel in the ceiling, and a particularly obnoxious CD rack whose panels vibrated like a drum. One by one I eliminated these resonating objects,by damping them with various dime store rubber bumpers or tying them down. I finally got to the end of the noise but one buzz/vibration remained.

To my surprise I discovered that the speakers themselves (both of them) were emitting sympathetic noise, between 20Hz and 100Hz, the worst of which seemed centered between say 40Hz and 90Hz. Salon 2s weight the better part of 175 pounds and I also have a pair of heavy JL Audio Subs contributing to the energy but it's the speakers themselves that are emitting the noises. The subs are crossed over to the Salons at 40Hz but don't seem to actually be producing spurious noises of their own. They may be contributing energy to the general situation that is causing the Salons to resonate but they are not the audible problem per se. The speakers are on their spikes which then want to penetrate a thick carpet and pad. Unfortunately, the underlying floor is soft and you can sense that it is likely part of the moving system that is creating this problem.

I thought rather than to try to couple the speakers to the floor with their spikes, I might look into isolating (decoupling) them instead. If I tilt either speaker onto two (of the four) spikes, the buzzes are significantly reduced. If I balance it on just one spike, the combination of whatever damping I am physically applying with my hands and the suspension of the whole speaker onto just one spike reduces the vibrations almost to inaudibility.

Sorry for this long winded explanation but perhaps it explains my interest in decoupling the speakers from the floor to the extent possible. So I'm looking into what materials and approach I can use to accomplish this at reasonable cost. Companies like Isoacoustics offer rather expensive solutions that may work but I am hoping that this can be done in a clever (cheaper) fashion if indeed such treatment is the most practical solution.

In sum, your experience with taming mechanically transferred vibrations of this type is welcomed and encouraged. I wasn't the guy who thought that isolating all the components in a system (at great expense) was a practical or necessarily proven thing to do but between the way the floor and my speakers and subs interact, I think I've got I've got a problem I can solve but I'm not sure exactly what to use to do that.
 
Check out Sorbothane. The heavier duty ones (something like 70 Duros) would work and are relatively inexpensive. I think it was $50 for speakers and two subs. They use them in industrial settings.
 
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To give a rule of thumb an isolator which will isolate down to the lowest audio frequencies will deflect around one inch when the weight of the speaker is applied and return to its static length quickly when the weight is removed.
Lossy polymers are good at absorption at medium and higher frequencies, less so at decoupling at lower ones.
 
To give a rule of thumb an isolator which will isolate down to the lowest audio frequencies will deflect around one inch when the weight of the speaker is applied and return to its static length quickly when the weight is removed.
Lossy polymers are good at absorption at medium and higher frequencies, less so at decoupling at lower ones.

This is not encouraging!
 
I decided to finally get rid of all the various mechanical buzzes and noises in my room. I ran tone at various frequencies between 20Hz and 100 Hz and just followed my ears to the various sources of mechanical noise in the room. This included framed pictures, a loose access panel in the ceiling, and a particularly obnoxious CD rack whose panels vibrated like a drum. One by one I eliminated these resonating objects,by damping them with various dime store rubber bumpers or tying them down. I finally got to the end of the noise but one buzz/vibration remained.

To my surprise I discovered that the speakers themselves (both of them) were emitting sympathetic noise, between 20Hz and 100Hz, the worst of which seemed centered between say 40Hz and 90Hz.

Have you checked for room modes in that region? Heavy resonances caused by room modes can make many things in the room to start rattle, including speakers themselves.
 
Check out Sorbothane. The heavier duty ones (something like 70 euros) would work and are relatively inexpensive. I think it was $50 for speakers and two subs. They use them in industrial settings.

I've looked into Sorbothane (one of my first notions) and just as you say it's another very inexpensive material solution....best place to source seems to be McMaster-Carr. I wonder if one makes up footers (or a solid platform), puts the material under the slab and then put the speakers on top of the whole sandwich? This for leveling and stability as much as making a useable sandwich of materials? There's getting the right material and then there's implementing the solution without spending $2000!
 
Hey, just noticed a typo. It’s duros not euros.
 
Have you checked for room modes in that region? Heavy resonances caused by room modes can make many things in the room to start rattle, including speakers themselves.

Of course there are room modes and I've done what I can. There are four GIK 8" bass traps (and gobos for higher frequency first reflections), and they help. The system is capable of a lot of output and to be honest, it's a beautiful sounding thing. You don't hear the buzzes when playing program (as independent artifacts) but you sure do if you run tone or a sweep. I don't think this is strictly an airborne problem (I don't rule that entirely out) but my playing around suggests it's more like there's a resonant mechanical effect at play here. I suspect my soft floor is at play here.
 
These are the best speaker isolating solutions I know of.
http://www.townshendaudio.com/hi-fi...ismic-isolation-bars-for-speakers-subwoofers/
They are extremely effective at isolating transmission between floor and speaker.
There may be others but most I see are polymer types which don't work for bass.

They look like they are intended to address my issue directly but they are an expensive option. I priced out Iso's Gaias (there have a PnP screw in package for my speakers) but I need the biggest ones which makes them an "investment" at $600 per speaker. $1200 for the Salons, another 1200 if I want to do the subs too. They get excellent reviews but as an objectivist I am a natural skeptic!
 
Hey, just noticed a typo. It’s duros not euros.

It's reasonable enough to experiment with (like Kal's recommendations) if I can devise the best way to use it. Now, what might that be?:)
 
Of course there are room modes and I've done what I can. There are four GIK 8" bass traps (and gobos for higher frequency first reflections), and they help. The system is capable of a lot of output and to be honest, it's a beautiful sounding thing. You don't hear the buzzes when playing program (as independent artifacts) but you sure do if you run tone or a sweep. I don't think this is strictly an airborne problem (I don't rule that entirely out) but my playing around suggests it's more like there's a resonant mechanical effect at play here. I suspect my soft floor is at play here.

The most effective method to tame resonant peaks is room EQ. If you can hear resonances during sweep they are there with music as well but masked with other tones so they are harder to hear. Can you post waterfall chart for left and right speaker?
 
Iso's Gaias
They don't look like isolators as much as absorbers.
Basically a set of correctly specified steel springs will isolate.
Expensive housings with bits of lossy polymer will absorb.
I think the Townshend isolators are absurdly expensive for what they are but they work correctly in an objective sense.
 
I decided to finally get rid of all the various mechanical buzzes and noises in my room. I ran tone at various frequencies between 20Hz and 100 Hz and just followed my ears to the various sources of mechanical noise in the room. This included framed pictures, a loose access panel in the ceiling, and a particularly obnoxious CD rack whose panels vibrated like a drum. One by one I eliminated these resonating objects,by damping them with various dime store rubber bumpers or tying them down. I finally got to the end of the noise but one buzz/vibration remained....
...In sum, your experience with taming mechanically transferred vibrations of this type is welcomed and encouraged. I wasn't the guy who thought that isolating all the components in a system (at great expense) was a practical or necessarily proven thing to do but between the way the floor and my speakers and subs interact, I think I've got I've got a problem I can solve but I'm not sure exactly what to use to do that.

Have you tried moving the speakers to a different location to see if they still resonate? They don't have to be moved to a final position, just moved for testing. You may just have an unlucky placement issue.
 
^That may well be but it would be a shame to have to move the mains out of their existing location as it's optimal for other characteristics. I have played with all the elements of placement for both the mains and the subs and have settled on a combination I like. I'm not stubborn so I take your idea as having value but it would be great not to have to reset the whole idea of the thing.

Problem is, I suspect shifting locations enough to reduce this problem will leave me with other issues. This is almost certainly a mechanical problem that ideally I would like to be able to resolve with a mechanical solution. I don't know where except perhaps for the corners (where floor strength is likely to be highest) but which presents other issues.
 
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