Daruma: Awesome vibration control device
Sep 12, 2002 at 3:47 PM Thread Starter Post #1 of 46

Anders

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Vibration damping is mostly relevant when you use speakers and the sound induces vibration in other components, especially source components as CD players and turntables. It should have very marginal importance for headphone only users.

I will here give my first, positive impressions of a medium expensive vibration device, the Final Daruma 3-II (about $100). I have tested it on a system with a Krell KAV-250cd, Krell 300i integrated amp and Revel Performa M20 stand-mounted speakers; with Synergistic and Nordost cables and medium-prize powercords. Components are placed on steady rack between the speakers. The rack was good looking and reasonably prized and I didn’t think about the glass shelves then, but have later understood that hard tree or fiberboard may be better. Glass is said to give a little bright sound.

There are several types of vibration damping devices. Soft shoes and hard cones or spikes are most common. The Daruma is entirely different and consists of two metal cups with a metal ball between. Three such devices are placed under the component that then floats in the horizontal direction, moving with the sound rather than absorbing vibration. In this aspect it is similar to much more expensive alternatives as Aurios and Rollerblocks.

It was easy to place the Daruma’s under the CD player. It is said that the surface must not be absolutely level and my rack tilts slightly (one degree or so). One has to be a little careful when touching the CD player, no heavy punches, but this is easy to adjust to. Earlier I had some cheap soft shoes under the player that made a slight improvement. After replacing them with Daruma, I listen to three selected CDs that I had heard recently. Testing was at a normal to high level.

1.Messiaen: Turangalila Symphony (good performance and recording on a 2 CD Naxos). This is a very rhythmic and intense piece with frequent crescendos. Sounds probably terrible on equipment that cannot handle it. It sounded quite good before the Daruma but I had problems with some brightness and the coherency tended to break up in crescendos. With the Darumas, brightness was reduced and instrumental timbre cleaner and with better texture. The soundstage deepened. The total improvement was more than marginal.
2.Rage against the machine: Rage against the machine. This CD sounded good before and I had nothing to complain about. With the Daruma it sounded as half an octave was added in the bass. I don’t think the actual volume changed, but the usable, good and well defined bass extended while resonances and soft, free-floating bass decreased. Cymbals sounded both somewhat more metallic (meant positively) and with more refined shimmer and ambience.
3.Björk: Post. A listened primarily to the second track with very high bass output. This previously flabby bass was now clearly tighter. What previously sounded overlaid on the music (cheap trick?) was now much more integrated with the music.

I didn’t feel any need for A-B testing as the differences were so obvious and easily could be analyzed, but not always easy to describe accurately in a foreign language. It was not the “it just sounds better experience” you can have on a good day.
The effect is not less, rather more than changing to a good IC or power cord. I believe it is replicable in most systems because of the principle of damping. Soft shoes and cones, what I understand, mainly works by changing the resonance to a less disturbing frequency and hard to predict (there is an interesting article about this in the Stereophile online archive, but I can’t remember the title just now). I don’t compare it to alternative damping devices, but for me the Daruma was a very good value.

You can find more information and reviews on www.finallab.com
 
Sep 12, 2002 at 4:11 PM Post #2 of 46
Quote:

Originally posted by Anders
Vibration damping is mostly relevant when you use speakers and the sound induces vibration in other components, especially source components as CD players and turntables. It should have very marginal importance for headphone only users.



Aren't some devices designed to direct internal vibrations away from a component, as opposed to isolating it from ambient vibrations?
 
Sep 12, 2002 at 4:22 PM Post #3 of 46
Maybee I said to much here. I haven't studied the problem of internal vibration, but it seems reasonable that some vibration energy could be dampended. In this case the internal vibration should cause the entire component to move. I don't know if this should induce less vibration (e.g. from a motor or power supply) into sensitive components, or not.
Haven't had time yet to test it with headphones.
 
Sep 12, 2002 at 4:48 PM Post #4 of 46
Yes the Daruma (as well as more expensive Aurios MIB & Symposium Rollerblock) bearing isolation devices can be very effective especially under CDP which generate rotational vibrations. I have owned all three and currently have a few sets of Darumas in my tweak drawer.

One problem (besides needing a close to level shelf) can be cables. If you have stiff cables that impede the free floating of component it will defeat the effectiveness of bearings, you want as much freedom to float unhindered as possible. Obviously lighter more flexible cables will work best.

My next project is to put Daruma bearings under my floor standing speakers, others have reported very positive results.

Ralphie the audio troll likes them:
Daruma
 
Sep 12, 2002 at 5:52 PM Post #6 of 46
bearings under speakers? i don't understand... i thought spikes on speakers were meant to keep the speakers in place... so all the energy used in moving the woofer cones would be used to move air, rather than moving the cabinet itself.

if it were possible to make a cabinet that does not move at all... theoretically an infinite mass, that should be the best performance of all.

putting bearings under a speaker is counter-intuitive. please explain.

dean
 
Sep 12, 2002 at 6:20 PM Post #7 of 46
Quote:

Originally posted by Orpheus
bearings under speakers? i don't understand... i thought spikes on speakers were meant to keep the speakers in place... so all the energy used in moving the woofer cones would be used to move air, rather than moving the cabinet itself.

if it were possible to make a cabinet that does not move at all... theoretically an infinite mass, that should be the best performance of all.

putting bearings under a speaker is counter-intuitive. please explain.
dean


Here is discussion at Audiogon by guy with very high end gear talking about results he acheived placing Dunleavy speakers on Aurios MIB Pro bearing devices. (click "system" after his name to view system)

Bearings & Speakers

Since I have extra Darumas, will only take a little of my time to find out for myself the results in my system.
 
Sep 12, 2002 at 6:50 PM Post #8 of 46
thanks.

well, i read his article... and it's mostly about the differences in sound he heard, and his experiments with the bearings and some pucks... but there is no explanation about WHY?

like i said, it makes no sense to put bearings or any other "viration" isolating feet unders speakers. the point of such devices is to take away vibrational energy away from the signal generating components insde the case. but we have a different situation here... the EXACT OPPOSITE of what you want in your audio components.

think about it in the sense of physics... the better the efficiency of energy transfer, the better for sound: the goal of a speaker is to have 100% of the energy coming from the amplifier be transferred to the air in the form of a compression wave. ...if you use bearings as feet, then energy that would otherwise be transfered to the sound wave in air would be transferred to the feet and dissipated in the form of heat (friction.) by using spikes as feet, you essentially make the cabinet an infinite mass, as you're coupling it to the earth; thus, the speaker cones move rather than the earth. simply put, if you have bearings under speakers, the cabinet will move instead of the cones... robbing your sound of acoustic energy.

again, you want to keep vibrational energy in the speakers, not dissipate it like in audio components.

so, why do you think he thinks he heard better sound with bearings?

and how the heck did he put these bearings under Dunlavy IV's!? damn... those things must weigh a zillion pounds... he must have had plenty of enthusiastic friends. ...i had 4 friends help me mount my 260lb Urei 815's... and almost had 5 broken backs!

heh he... anyway... don't get me wrong... i just want to hear an explanation of WHY, not a subjective discussion of what you hear.

dean
 
Sep 12, 2002 at 10:21 PM Post #9 of 46
Dean
Don't have any scientific explanation to put forth, but I have heard others with high end gear mention positive results putting bearings under large speakers.......worth a try for me since I already have the Darumas, I am currently using large brass cones.
cool.gif


I have played around with system two, decoupling my small 2 way speakers from thier sand filled metal stands by placing vibrapods between speaker and stand, which yeilds some very interesting results:

-noticeably deeper bass and low midrange, produces a slightly warmer sound.

-soundstage surprisingly was larger and more developed

-the possible downside was slightly less treble energy and extension, but still didn't seem to be less detailed, just more musical.

Obviously by placing vibrapods under small speakers they are freer to vibrate (decoupled from stands) and I was expecting a smearing and drop off of detail, but this wasn't the case. Again this is very easy and cheap tweak to try if you have stand mounted speakers and a few vibrapods.

I have kept this set-up on my small speakers, and prefer it to the rigid spike/blue tac coupling to sand filled base most often used and recommended. I did try this with my large floor standing speakers using very large #5 vibrapods, but in this case bass response was too over emphasized and cones were preferred.
 
Sep 13, 2002 at 12:37 AM Post #10 of 46
very strange.

but... what i say does make sense to you right?

...well, the final judgement should be left to your ears, since it's your ears that we are trying to please in the first place.

but i think to sum your opinions up, i think you are suggesting that heavy and expensive audiophile speaker stands are not necessary, nor are spikes. this is very unconventional.

does anyone else also believe in decoupling the speakers?

dean
 
Sep 13, 2002 at 1:07 AM Post #11 of 46
Orpheus,
The physical explanations and a comprehensive understanding of the processes is way too complex for me. Maybee, a four week fulltime college course could help, but I have no time for it and don't develop devices myself.
Different argument are made. The spike school argue from the Newton principle of action and reaction and believe that the resonance energy can be dumped through spikes into a solid structure as a floor. I have no idea of to what extent this works in reality, but that there are positive listening reports. This is also the case for different kinds of damping that according to theoretical arguments is either impossible or ideal. I suspect that the physical reality is more complex than is accounted for in simple models.
Anyway, the initial listening impressions of the Daruma hold this far. The half octave bass increase is consistent for other records with heavy bass content, and the octaves above seem to clear up on all. A rather cheap and substantial improvement.
Many other than DarkAngel have reported positive impressions of soft shoes under speakers. I didn't think of this between speakers and stands, but will soon test how it works in my system. This is a simple and cheap test.
 
Sep 13, 2002 at 1:09 AM Post #12 of 46
For the DIY'ers (and the cheapskates like me), it is possible to make some Daruma clones. I made mine by buying some steel balls from (http://www.smallparts.com) and some spoons from the local Walmart (tablespoons better than teaspoons). I cut some small squares (about 3" x 3") from an oak board and I used a router to cut a small concave depression on one side of the oak board (just large and deep enough to accept the spoon curvature). I then broke off the handle of the spoon and glued the spoon intho the oak square with some construction glue.

I set them up under my components (3 per component) with a small piece of plate steel (or anything hard and smooth) on my rack, then the steel ball on the steel plate and the spoon/oak square on top of the ball (spoon facing downward). It takes some time to get the whole thing set up and balanced (a little frustrating), but once it is balanced correctly they work very well.

A simple and worthwhile tweak. Some have called these Diyumas.
 
Sep 13, 2002 at 2:35 AM Post #13 of 46
k... sorry... last one. i know that this thread is about the Daruma... so i'll keep this one short.

the point is, by physics, Darumas should not inhance the sound of speakers. they have the EXACT OPPOSITE properties of spikes... spikes couple the speakers to the stands/earth... while Darumas decouple.

spikes effectively Increase the mass of the cabinet while Darumas effectively Decrease the mass of the speaker system. you might as well just suspend the speakers in air, rather than mount them in a cabinet. it's the same idea.

try this... the perfect Darumas are not the ball bearing designs... but a perfect suspension of the speakers in air. if you want to experience true decoupled speakers.... tie a light bungee from the top of your speakers to your roof... or a spring. either should work.

dean
 
Sep 13, 2002 at 11:48 AM Post #14 of 46
Anders
If you look close enough you will see the vibrapods under my 2 way speakers. The top of metal stand has small platform so I used larger glass/plastic cutting board under speaker to allow more spacing for Vibrapods.
Vibrapods

Dean
Versions of the Aurios bearings are used in other commercial critical vibration control applications including electron microscopes, precision photolithography gear (chip circuits) etc, mechanical theory is well founded, tested for bearing isolation.
Aurios MIB
 
Sep 13, 2002 at 1:08 PM Post #15 of 46
dark, i'm not saying they don't work for anything. i'm just saying they won't work for speakers. i am not calling you a liar.... if you like the sound, that's fine. they absolutely should not work for speakers. if you doubt me.... call up a speaker engineer, not the rep, and see what he says.

but i know you like the sound.... and i am here to learn. that is why i want someone to tell me a reason WHY it sounds better for speakers. i already told you why it won't work for speakers... and i have a pretty good understandning of physics. if you would like to verify with a professor at a unversity, i'm sure he'd agree with me too.... or if he doesn't, i would really like to know WHY.

but really.... don't get me wrong, this is just an educational discussion for me. i like to learn.

you know... i once visited a Northrop plant where they were making some stealth fighters... i think that since even miss-rivetting something by a millimeter is enough to cause enough turbulance to tear the plane apart at supersonic speeds.... so, all their machinery was mounted on servos that move according to the rise and fall of the nearby ocean... and also i believe they had active vibration controls, as in a computer actually monitoring vibration, and thus actively adjusting dampening. heh he... maybe you can ask Northrop to make you some.... might cost a couple million dollars....... but it's the best. heh he.

thanks,
dean
 

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