Measurement Thread: Measured Effect of Speaker Isolators

[DaveC]

Sure, but just because John can measure cabinet vibration with an accelerometer doesn't mean that the vibration is audible. As with all other aspects of audio and fidelity, we can measure much smaller quantities than anyone can hear. Can anyone hear 0.001 percent distortion? Of course not, but that small amount is easily measured. The same for cabinet vibration. I'm not saying there's no loudspeaker in the world that will sound different on an isolating platform. But my measurements clearly show no real change in sound that can be attributed to the devices I tested using a typical competent loudspeaker. So as far as I'm concerned, the burden of proof is clearly on those who continue to believe that isolation affects the sound. As always, I'm glad to change my opinion in the face of hard evidence. Not someone's say-so, but actual evidence.

--Ethan

Burden of proof is on nobody, no one is responsible for explaining how things work to you. You might wish isolation products had more measurements to understand how they work, but there's engineering texts for that, it's a pretty big subject for mechanical and acoustic engineers.

And, you were measuring the wrong thing anyways.

 

[Gregadd]

The burden of proof rests on the person who puts forth the hypothesis or the person who attempts to refute a valid study. In order to establish proof you must adequately define the population and randomly select a sufficient sample size, inter alia. Before anyone needs to refute anything they need to be convinced of the studys' validity.

Edit: The size and random nature directly relates to the confidence level.

 

[DaveC]

The burden of proof lies on the person who puts forth the hypothesis or the person who attempts to refute a vlaid study. In order to establish proof you must adequately define the population and randomly select a sufficient sample size, inter alia. Before anyone needs to refute anything they need to be convinced of the studys' validity.

That's only if you care... I'm not writing a scientific paper nor do I care what beliefs other hold. They can do their own experimentation or whatever, I have no responsibility to prove anything.

 

[Ethan Winer]

Burden of proof is on nobody, no one is responsible for explaining how things work to you. You might wish isolation products had more measurements to understand how they work, but there's engineering texts for that, it's a pretty big subject for mechanical and acoustic engineers. And, you were measuring the wrong thing anyways.

LOL.

So what should I have measured? Before you answer, realize that REW measures everything audible at once, and then later you can display different graph types as needed. So what type display would you like to see to "prove" that those loudspeaker isolation products did anything useful?

--Ethan

 

[FrantzM]

Every speaker in existence will benefit from decoupling.

Resonances are different from vibration, and while good cabs will be free of resonances they will never be free of vibration and if the speaker isn't decoupled vibration will be transferred to whatever surface it's sitting on. If it's the floor it'll drive the floor... this is not good.

All it takes is getting a pair of IsoAcoustics stands, stillpoints, etc. , put a speaker on it and hear the result. You can measure vibration on the floor around the speaker and I'd guarantee it'll be reduced.

This is in the category of SUPER-OBVIOUS imo... the results of decoupling speakers are easily audible.

You can also look at the speaker cab testing done by JA at Stereophile. Every single one will have measurable vibrations. Some even have resonant modes.

So why are those decoupling apparatus NOT part of the original design in those uber-expensive speakers? Just asking

 

[Purite Audio]

Sure, but just because John can measure cabinet vibration with an accelerometer doesn't mean that the vibration is audible. As with all other aspects of audio and fidelity, we can measure much smaller quantities than anyone can hear. Can anyone hear 0.001 percent distortion? Of course not, but that small amount is easily measured. The same for cabinet vibration. I'm not saying there's no loudspeaker in the world that will sound different on an isolating platform. But my measurements clearly show no real change in sound that can be attributed to the devices I tested using a typical competent loudspeaker. So as far as I'm concerned, the burden of proof is clearly on those who continue to believe that isolation affects the sound. As always, I'm glad to change my opinion in the face of hard evidence. Not someone's say-so, but actual evidence.

--Ethan

I don't believe isolate can affect the sound quality of the loudspeaker , the loudspeaker designer has to ensure the speakers enclosure does not store energy which will lead to resonance and colouration, but isolating the loudspeaker from the floor may make you more popular with your neighbours.
If you are going to experiment with isolation you need a properly loaded viscoelastic material , or rolling air diaphragm isolator, cup and ball designs will have no effect whatsoever as they directly couple in the vertical plane, thus no different to hard feet or spiking.
Keith.

 

[Gregadd]

http://hyperphysics.phy-astr.gsu.edu/hbase/class/phscilab/speakerres.html

 

[Gregadd]

 

[Gregadd]

Now if you are worried about speaker height you already have a solution in your home,probably.You just need one of those office chairs with pneumatic height adjustment.

[
If your speaker is flat you can pace a glass of water on it. You'll be able to see any vibrations in the waters wake.

If f you have a laser you can use that alsoo.

While 1-2 db is barely audible, it is audible. There may be a cumulative effect. Only the speaker was measured in this exmple.
http://www.silcom.com/~aludwig/EARS.htm

 

[Gregadd]

Ethans' potential Biias/Conflict of interest

,Let me count the ways. i know you are thinking, why is Greg picking on Ethan? It's fair game right? He advocated a position that is subject to peer and public comment.He likes to talk a lot about bias.

I submit he has potential,personal, philosophical and financial bias.
He is part owner of a company that sells products designed to deal with airborne vibrations. That's a financial interest.The name of that company should be listed in his signature lline according to WBF TOS. His hostility to audiophile products and tweaks in particular is well know. He ahad serious debate with Synergistic Research on another frum.He was banned from this forum in a thread over aheated discussion over vibration isolation devices.ing products it is essential

When testing products it is essential that they be chosen at random. If not any results have to specify the items included in the experiment. You can't generalize from the specific. Citing a few examples of questionable aand hyperbolic cpraise is meaningless. fFnding a product that does not work or an example of hperbolic praise proves nothing that general applicability. findindg a reviewer who claims a product has dramtic effects proves nothing outside that reviewer or customer.
"I believe" may be a good C.Y. A. phrase but is not a substitute for a valid conclusion based on proof. Neither is making a statement that is true on its face but offers no support to the conclusion.

 

[amirm]

I heard from Ethan last sunday that he can no longer log into the forum. Whether his account is "hacked," him not knowing how to login, or his access terminated, I don't know.

 

[spazmatron]

well thats a shame, i dont agree with everything ethan says but i really like him. to me he is a inspiration. lets hope he sorts out this log in issue.

 

[NorthStar]

Ethan is one one the most friendly and humorous and sound knowledgeable friends that I've got.
He has all the human requirements to be a free citizen without prejudice. Thousands and thousands of people learn a great deal from this beautiful man.
Let him be. Don't cut us out from his participation and knowledge, respect him as you respect yourself. Give him full access.

 

[Gregadd]

The question is will Ethan leave others alone. This thread begins with a link to Ethans experiment posted on his we site.The conclusion suggests the manufacturererstwhile are selling a placebo. The reviewers are misleading their subscribers.The subscribers are suffering from some cult like delusion.
He has posted this on his website.
What are they to do? Ignore it because he is a nice guy. What he is basically saying is don't buy this product because at best it's a placebo and at worst it's a fraud. By posting on his website he is broadcasting it to the general public. Thats serious business.

 

[NorthStar]

And you just said it Greg; people are taking life way too much serious. If the world would relax a bit more and accept various styles we'd be much better off.
Take the balance between measurements and your own set of ear's preferences in the music and sound you hear.
Experiment, discover, learn, master the art of advancement in all matters of science and happiness. We're all in it on the same planet, with various roads leading to various goals.

If we can isolate our speakers and that they both sound good and measure good, then something is working right.

 

[Gregadd]

Ethan is one one the most friendly and humorous and sound knowledgeable friends that I've got.
He has all the human requirements to be a free citizen without prejudice. Thousands and thousands of people learn a great deal from this beautiful man.
Let him be. Don't cut us out frHm his participation and knowledge, respect him as you respect yourself. Give him full access.

Ethan has not been silenced. He has his book, his website.Hydrogen Audio and You tube, and probably some other outlests of which I am unaware.

 

[NorthStar]

Ethan has not been silenced. He has his book, his website.Hydrogen Audio and You tube, and probably some other outlests of which I am unaware.

I know that Greg. I'm only referring to here, @ WBF. Ethan is an expert on room treatments, acoustics...he helped many music/movie lovers.
And WBF is after high caliber experts like Ethan. I know so...many members missed the good old days; they said it many times.
But experts need an audience, and the smartest the audience the smartest they are @ mastering their own expertise by learning some more themselves.

Expertise is the art of being open to advancement in knowledge by further theories and experiments; in audio as in any other subject. That's the true science.

 

[Gregadd]

I am hardly one to speak.but I find nothing unique about Ethan's' expertise.Furthermore you can get it all on his website. Every point I made was valid criticism of Ethan's' experiment and not a personal attack. i presumed he was fully avaiable to respond to my criticism. I have no say in his status in WBF. I was not even present on WBF when he was banned. I can say, you do not know the whole story and I am not about to tell you.

 

[Gregadd]

I had a pair of Janis subs.They made the carpet they sat on vibrate.I contacted Sound Anchors. I had them make me a pair of custom stands. Problem solved.

 

[amirm]

Personally, I don't think vibrating carpet is something I want fixed.