[Æ]

Lower mass so you're not messing with the resonance design of the loudspeaker.

That really doesn't make any sense to me.

Loudspeaker enclosures are most often designed to be non-resonant, not resonant. Well, if you have a bass reflex enclosure then the port is supposed to resonate because it's a Helmholtz resonator. But otherwise any other resonances are detrimental and most designers take steps to eliminate as many cabinet resonances as possible.

And I fail to see how less mass under your loudspeakers is going to help, unless of course you are on a raised wood floor and the floor has it's own particular springy compliance.

[ssglx]

All speakers resonate. Damping/absorbing the energy, draining it rapidly away, and adding mass that is coupled or partially coupled will change the sound. And definitely not always for the better soundwise.
Big debates about what is "best" on audioasylum, and different approaches by manufacturers (Harbeth for example).

My experience with my speakers and best results are achieved by leting them resonate uncoupled to the stand. Incredible microdynamics and nuance in the bass. Coupling to lead absolutely killed this.

Adding mass changes the bass response of the speaker too.

Try these things for yourself.

Just one of many posts on this subject:
http://www.audioasylum.com/audio/speakers/messages/163625.html

[Quiet Earth]

If you attempt to decouple the speakers from the stands, then it won't make alot of difference what you use to fill the stands.

ssglx,

What are you using to decouple your speakers from the stands? I would be interested in hearing what other people are using too, whether they are trying to couple or decouple.

[spinner]

 You don't seem to understand some basic physics . Mass absorbs energy(in this case unwanted resonance) It's a simple concept . Try it. 

[rmurray]

 Concrete would make a great stand as well as an enclosure. It's hard to make cement look nice however. As for mass in the box, it certainly improved my sound as well. The bass is tighter and hence the mids are clearer . I assume the extra mass keeps the cabinet more motionless.  I think the term " not getting it" means that for speaker fans it's hard to imagine that so few have not tried this experiment. Filling the stands both stabilize and deadens them. How could that be bad....two for the price of one !

[Quiet Earth]

Mass absorbs energy

What does it do with the energy after it absorbs it?

in this case unwanted resonance

In this case, it sounds like the resonance was wanted. Go back and re-read the OP.

It's a simple concept . Try it. 

Try what? It's hard to tell if you are for or against mass loading. And if either, why?

it's hard to imagine that so few have not tried this experiment.

I think that most of us have tried it. So it's not a question of "getting it", it's a question of trying to understand why we might prefer "it" one way or the other.

[Æ]

All speakers resonate. Damping/absorbing the energy, draining it rapidly away, and adding mass that is coupled or partially coupled will change the sound. And definitely not always for the better soundwise.
Big debates about what is "best" on audioasylum, and different approaches by manufacturers (Harbeth for example).

My experience with my speakers and best results are achieved by leting them resonate uncoupled to the stand. Incredible microdynamics and nuance in the bass. Coupling to lead absolutely killed this.

Adding mass changes the bass response of the speaker too.

Try these things for yourself.

Just one of many posts on this subject:
http://www.audioasylum.com/audio/speakers/messages/163625.html

Please, don't tell me to go there. There is a reason why it's called an "Asylum."
Psychoacoustics, usually more psycho than acoustic.

Damping requires some sort of force, mechanical or otherwise. True, mass alone doesn't kill resonances, it just moves them to a lower frequency. What you really need is a compliant mass. You need to fine tune the ride.

Back in the days of Speaker Builder magazine (I had each and every issue) you would read of thick tar/bitumen and sand mixtures being applied to the interior walls of loudspeaker enclosures. Very effective, but awfully messy and the outgassing (vapors) continued for quite some time.

What you are really saying is you like damping through only a certain tonal range as opposed to eliminating all extraneous tones. Which is certainly fine if you enjoy it that way, after all it's about musical enjoyment.

I take it you haven't built very many pairs of loudspeakers? Never ran any frequency response curves? Never struggled trying to pin down the source of some strange resonance?

Do you have any test CDs? Run a 20Hz-20KHz log sweep and you'll quickly discover just how many resonances are present not only in your loudspeakers but in your listening environment too! If you really want to refine it, run the frequencies while using a stethoscope, just like auto mechanics do it.

Yes, I have a stethoscope.

[Letitroll98]

I think it's a case of no one way being correct.  If you are looking to damp all resonances with the goal of letting the drivers speak for themselves, you want lots of mass in your speaker stands, and also in your cabinets.  Some others look at the speaker as a musical instrument with the cabinet contributing to the sound, and may not want to dampen those resonances.  Not as accurate in a laboratory sense, but perhaps more musically pleasing to some ears.

That being said, the OP is asking for material to best dampen his speaker stands, so while neither camp has a stranglehold on correctness, the resonant crowd (ssglx so far it appears, if one doesn't include the Asylum) is on the distaff side in this thread.

For myself I haven't made a decision, I read arguments on both sides, decouple or couple tightly, tried both, with no consistent results with several speakers and several speaker stands.  The only thing that has worked positively in every case is Maple, the thicker the better.  Don't know what to conclude from this.

[ssglx]

Quiet Earth, I use vibrapods. I was surprised and pleased at the terrific HF and upper midrange purity and clarity I achieved. Nearly as clear as AudioPoints, but with more energetic bass.

AE: There are smart folks on AudioAsylum as there are here.  I don't need to compare credentials with you. I haven't built speakers since I was a kid in the early 70's, but I sure have experimented with them, for 40 years or so.
I am an engineer, but not in acoustics.

[Quiet Earth]

Thanks man! Much appreciated!!! 

I'm using blu tak right now, but I am open to the idea of experimenting.

[Æ]

Æ: There are smart folks on AudioAsylum as there are here.  I don't need to compare credentials with you. I haven't built speakers since I was a kid in the early 70's, but I sure have experimented with them, for 40 years or so.
I am an engineer, but not in acoustics.

Quite some years ago I worked for a small audio company. We had some lightweight hollow acrylic spheres that needed damping. We decided to experiment with two part fast curing marine grade (expanding) foam. The spheres were about 14 inches in diameter, made from two hemispheres which were glued together. The glue seam was sanded smooth and then the entire sphere was painted.

Being completely hollow, they had a sort of plastic bell sound when you flicked them. Filling them with expanding foam took care of the problem. When we began filling the first sphere, I over estimated the amount of liquid to mix. The foam grew and grew and grew and finally the pressure built up to the point where it split the sphere in two, spraying foam in my face and all over the place. We got a good laugh out of that one.

Anyway, the company later switched to some of that hot dispensed foam that is used commercially for packing, for doing custom fittings inside a crate or box. It was denser and worked even better.

I've tried those same types of foam inside metal stands, it barely had any effect at all. It all depends on the density of the material you are attempting to damp. Heavy materials require heavy damping.
Mass is always a consideration. You can easily damp car doors with that peel and stick (Dynamat) type of stuff, but if you try and use that same peel and stick inside your wood product loudspeaker cabinet the results aren't nearly as satisfying. Not until you've built up several layers.

Now concerning that other website you mentioned, if you like them it's fine by me. But I'm not so gullible as to fall for attaching little bags of "magic" rocks to my breaker panel and all the rest of my audio equipment. Well maybe if you filled your loudspeaker stands completely with rocks it would be magic.

[Letitroll98]

Æ, I think I read you as saying if you're going to fill a speaker stand, using lightweight materials like kitty litter or foam are counter productive?  Does that translate into the heavier the better no matter what, or do inherent damping factors also contribute?  i.e. high metallic content sand possibly mixed with a certain percentage of lead shot, would be better than either lead shot alone or lightweight, high damping factor materials.  A case where conventional wisdom is correct? 

Not sure what the magic rocks in the circuit breaker box have to do with the discussion, but the ERS paper looks intriguing.  Perhaps I'll try it.   

[redbook]

 I would say that the" getting it " about mass loading means open your mind to this possibility. It may not work for everyone's speaker system. As for the energy absorbed it is turning to heat.

[spinner]

  Thanks redbook. Yes I am all for experimenting with mass as well as any other creative measure to improve performance. Putting more stuffing(not turkey stuffing) into the enclosures was another improvement in my case. The deader the box the better hear what the drivers are up to. As a result the overall effect has been a positive effort. 

[redbook]

 The question as to why is to remove unwanted resonance of the cabinet.A speaker company can only go so far to do this because of cost factors. When you look at a lot of extremely expensive units they are often VERY heavy! Stiffness plays a role but put that with some weight and it's the best of both worlds, Works for me could work for you......get it now?   

[Æ]

Not sure what the magic rocks in the circuit breaker box have to do with the discussion, but the ERS paper looks intriguing.  Perhaps I'll try it.

Correct, that picture has nothing to do with filling loudspeaker stands. Just my way of refuting one of his claims. That picture originated at that other website. You know what they say, a picture is worth a thousand words. As you can see by the picture, it's a thousand words of lunacy.

I don't know about the efficacy of ERS paper. Seems to me (logically) that you'd need to enwrap the entire breaker panel box for it to be truly effective. And if EMI/RFI is radiating from your breakers, what about the Romex that carries current throughout the rest of your house?

[Æ]

There is one thing worse than beating on a dead horse.

Betting on one!

[Letitroll98]

Correct, that picture has nothing to do with filling loudspeaker stands. Just my way of refuting one of his claims. That picture originated at the AudioAsylum. You know what they say, a picture is worth a thousand words. If the picture is from the AudioAsylum, then it's a thousand words of lunacy.

Well, we do have a no dirty laundry policy here, e.g. not denigrating other sites or bringing fights from other places here.  While I don't believe this is a violation, it is skirting the edge of that territory.  I think we can leave it as there are smart people on the Asylum and we're not posting there presently for whatever reason.

And yes, I don't think I'll actually be running out to put any ERS paper in my circuit box. 

[Æ]

Well, we do have a no dirty laundry policy here, e.g. not denigrating other sites or bringing fights from other places here.  While I don't believe this is a violation, it is skirting the edge of that territory.  I think we can leave it as there are smart people on the Asylum and we're not posting there presently for whatever reason.

And yes, I don't think I'll actually be running out to put any ERS paper in my circuit box.

I edited my posts, removing the name of that other particular website/forum.

I wonder if ERS paper is flammable?

[Bob in St. Louis]

[thinkingtoonesself]is this thread worth the email notifications any longer[/thinkingtoonesself]