Vibration Management

[PeterA]

I would like to thank member Stehno for posting some very interesting comments about vibration management that have me rethinking my approach to and understanding of this fascinating topic. Here is what he posted in the Introspection and hyperbole control thread in a discussion about an amplifier stand. As I understand it, all components suffer from vibrations which adversely effect sound quality. As I understand it, Stehno believes that these vibrations need a path on which to travel away from the component. Isolation breaks this path and traps the vibrations within the component where they wreak their havoc. I think this topic deserves its own thread and might prove very interesting with regards to the several threads about active and passive isolation devices.

Quote Originally Posted by PeterA View Post
Stehno, you write some interesting stuff. Could you be a bit more explicit about proper vibration and AC management?
Thanks, Peter. My primary reason for responding was 1) you asked some very basic and sound questions that deserved sufficient answers that as Microstrip alluded, and I'm confident nobody else could sufficiently respond. And 2) because Microstrip clearly said, nobody had a clue. Though it seems he's now backing away from that claim. And I suppose I wanted to offer a hopefully straight-forward response before some "expert" stepped in to describe what a tremendously difficult scientific feat it is for them to "isolate" vibrations in our vibration-rich universe.

Quote Originally Posted by PeterA View Post
To what products or designers do you refer?
I'm not sure I referred to any specific product or designer but if any such manufacturer or enthusiast ever uses the word "isolation" in a positive sense I suppose I'm referring to potentially everybody.

Quote Originally Posted by PeterA View Post
I think I recall you describing your rack and the importance of mechanical clamping in its design. I assume you prefer a combination of energy drainage away from the component and isolation of external sources of vibrations. The two in combination should be effective.
Yes, no, and no.

Yes. Although the rack design is of paramount importance, surely many of us are aware of those who mass load their components with some form of weight placed on top usually in the 25 lbs. to 50 lbs. range and then swearing by their performance benefits. Years ago I did some experimenting over about a 6 month period of time and made a few interesting discoveries along the way. As a result and in contrast to the lightweight freestanding mass loading methods others use, I currently invoke an extreme form of clamping on my components where I’ve roughly 1000 lbs. of compressive force on my mono-block amps sandwiching them to the shelf, over 650 lbs. on the CDP, and well over 300 lbs. on my small passive line conditioners. I would add that every one of those pounds count toward performance. But as important as that is, there’s more to it than just extreme mass loading.

No. As I said earlier, I never use the word isolation in a positive sense but only in the negative and for several reasons. 1) I see no reason why I should spend any of my time working against basic laws of nature trying to achieve the impossible even though some other really smart fellers will go to their graves trying to achieve what is not possible and ta take others’ money in the process. 2) Since there are multiple sources of vibrations that potentially induce sonic harm, apparently nobody else but Microstrip and I are the only ones who understand that if I should isolate our sensitive components from a single vibration source (which is possible), inherently and immediately I’ve just trapped all vibrations that enter the component from other sources. That’s like one step forward and at least one step backward and when dealing with such fundamentals, there’s absolutely no reason for any such compromise.

Besides, as I mentioned earlier, resonant energy seeks first and foremost to travel. That’s a big fundamental so my goal is to do what I can to allow that to happen and I go to tremendous extremes to perform due diligence there.

No. As I shared earlier, although “isolation” based products can leak out some performance benefits provided the design strays from the isolation method. But isolation is nothing more than a grotesquely inferior form of superior vibration management and hence has no place in my executions. Strategic damping, yes. Isolation, no. See above.

Quote Originally Posted by PeterA View Post
Could you copy or move some of your posts in this Introspection and hyperbole thread to a new thread dedicated to addressing the challenges of vibrational energy?
I've no problem discussing at least to some extent what I think constitutes superior forms of vibration management so if you wanna open a new thread I'd be happy to participate.

 

[Mike Lavigne]

i respect that Stehno likes extreme mass loading. but i disagree that his preference proves anything at all. it's simply one approach where he prefers what he did to other alternatives he tried. mass loading can only change the resonate frequency of vibrations, it does not eliminate or drain them.....in fact they can be 'held' and reflect with additional mass as that mass and it's inertia sets up oscillations.

and excuse me if my post here has missed the mark of the point you are making Peter.

i would challenge Stehno to compare his extreme mass loading to the best active isolation approach. until he goes down that road his broad view is missing an important comparator.

and mass loading the top of a chassis proves nothing about whether the mass loaded gear will sound better sitting on a grounded rack or active or passive isolation. some chassis do benefit from some sort of treatment to the top or inside. what they sit on is another matter. depending on how much mass is loaded on top of gear, it can affect what sort of isolation might work. common sense must be applied. if you use 300 pounds of mass loading on top of gear then trying to isolate/decouple that somehow gets challenging.....but it can be done.

further; between extreme mass loading and ultimate active isolation we have an almost infinite amount of variations of mass loading to variations in passive isolation or combinations of both where it's about execution and preference.

i would agree that for a DIY'r; mass loading can be a cheaper approach. it is cheap (and ugly) to add bricks on top of gear. again, that is separate from which approach works better.

as far as what a circuit requires for ultimate performance we turn to science/industry. and for their most delicate processes they mostly take the resonance isolation approach. not extreme mass loading.

reproducing music is not building a bridge abutment, it's capturing and relating the delicate nuances of music.

and generally mass loading will change the tonal nature of gear compared to decoupling/isolation, many times deadening the sound compared to it's designed intended tonal balance. but each situation is different.

in my system i have examples of extreme mass loading (3000 pounds of speakers), and active isolation for most electronics and tt. i do mass load the top of some gear with Walker lead filled pucks that have a resonate chassis, but still passively isolate that gear below it. the proof is in the listening.

Stehno is just down the road in Oregon, he is welcome to drive up and visit my room to hear for himself.

 

[microstrip]

(...) Thanks, Peter. My primary reason for responding was 1) you asked some very basic and sound questions that deserved sufficient answers that as Microstrip alluded, and I'm confident nobody else could sufficiently respond. And 2) because Microstrip clearly said, nobody had a clue. Though it seems he's now backing away from that claim. (...)

No, Peter, I did not say that nobody had a clue. What I said it that everyone has a different clue on the subject, mainly because there is no definitive or scientific theory behind the effects of vibration control in solid state electronic audio equipment and its connection to people subjective preference. So everyone has its preferred "clue" and says his one is the correct and the truth. Some ones even pretend all others are mislead...

 

[PeterA]

No, Peter, I did not say that nobody had a clue. What I said it that everyone has a different clue on the subject, mainly because there is no definitive or scientific theory behind the effects of vibration control in solid state electronic audio equipment and its connection to people subjective preference. So everyone has its preferred "clue" and says his one is the correct and the truth. Some ones even pretend all others are mislead...

Micro, I don't think you mean to address me in your post. I made no claims about what you did or did not say. I think you are referring to Stehno.

 

[microstrip]

Micro, I don't think you mean to address me in your post. I made no claims about what you did or did not say. I think you are referring to Stehno.

Sorry, I could not separate what you were quoting from others or saying in your OP. Anyway I think my opinion is now clear.

 

[Stacore]

No, mainly because there is no definitive or scientific theory behind the effects of vibration control in solid state electronic audio equipment and its connection to people subjective preference.

After some surprisingly positive listening tests with pure solid state gear, I have two working hypothesis:
- moderate: big caps are vbration sesnitive
- crazy: piezoelectric effect in semiconductors (?) hope to find time to study this a bit more

As for the OP, I can say three things:

a) damping alone is usually not enough, how can one damp say subsonic, large amplitude vibrations without any isolation mechanism?
its a smart combination of damping and isolation which makes for an advanced vibration control

b) mass load is a double edge sword: remember that the damping of a pendulum *decreases* with the mass and so its natural frequency
one has to use it smartly

c) i very much like the idea of clamping the devices to the shelf to control the chassis resonances; i imagine e.g. a plate that you put on top of the device and then clamp with 4 threaded rods to the shelf, sandwitching the device

Cheers,

 

[PeterA]

I don't have the impression that Stehno is talking about only mass damping his components. I think he is most focused on energy drainage and providing a direct, uninterrupted path along which vibrational energy can travel away from the sensitive circuits of components. I also think he acknowledges the benefits of isolating components from certain types of environmental vibrations like the floor, but if a component is isolated from the floor, airborne vibrations still reach the component and if it is isolated, then there is no path along which those external vibrations can exit the component. I don't think Stehno is saying that mass loading is a complete solution. If I understand him, he has extreme pressure exerted on his component chassis, probably by clamping. And the contact plates form a path for the vibrations to exit along the structure of the clamping/rack mechanism. It seems that the pressure is not from mass alone, but rather from clamping, or a combination of the two. Or, perhaps I am misunderstanding his posts.

Stehno, could you elaborate?

 

[jeromelang]

What do you listen for to know if vibration control is effective?

Soundstaging?

Imaging delineation?

Imaging perspective? Move backwards or come forward?

Frequency extension?

Tonal balance?

 

[the sound of Tao]

i respect that Stehno likes extreme mass loading. but i disagree that his preference proves anything at all. it's simply one approach where he prefers what he did to other alternatives he tried. mass loading can only change the resonate frequency of vibrations, it does not eliminate or drain them.....in fact they can be 'held' and reflect with additional mass as that mass and it's inertia sets up oscillations.

and excuse me if my post here has missed the mark of the point you are making Peter.

i would challenge Stehno to compare his extreme mass loading to the best active isolation approach. until he goes down that road his broad view is missing an important comparator.

and mass loading the top of a chassis proves nothing about whether the mass loaded gear will sound better sitting on a grounded rack or active or passive isolation. some chassis do benefit from some sort of treatment to the top or inside. what they sit on is another matter. depending on how much mass is loaded on top of gear, it can affect what sort of isolation might work. common sense must be applied. if you use 300 pounds of mass loading on top of gear then trying to isolate/decouple that somehow gets challenging.....but it can be done.

further; between extreme mass loading and ultimate active isolation we have an almost infinite amount of variations of mass loading to variations in passive isolation or combinations of both where it's about execution and preference.

i would agree that for a DIY'r; mass loading can be a cheaper approach. it is cheap (and ugly) to add bricks on top of gear. again, that is separate from which approach works better.

as far as what a circuit requires for ultimate performance we turn to science/industry. and for their most delicate processes they mostly take the resonance isolation approach. not extreme mass loading.

reproducing music is not building a bridge abutment, it's capturing and relating the delicate nuances of music.

and generally mass loading will change the tonal nature of gear compared to decoupling/isolation, many times deadening the sound compared to it's designed intended tonal balance. but each situation is different.

in my system i have examples of extreme mass loading (3000 pounds of speakers), and active isolation for most electronics and tt. i do mass load the top of some gear with Walker lead filled pucks that have a resonate chassis, but still passively isolate that gear below it. the proof is in the listening.

Stehno is just down the road in Oregon, he is welcome to drive up and visit my room to hear for himself.

Great post, effectively using mass loading requires listening in evaluation. Not just the mass but also the material and its resonant qualities comes into play. It's just as easy to make detrimental effects on the sound quality of a system by over damping the components as it is to make a room sound dead and lifeless by over treating it.

 

[PeterA]

What do you listen for to know if vibration control is effective?

Soundstaging?

Imaging delineation?

Imaging perspective? Move backwards or come forward?

Frequency extension?

Tonal balance?

The addition of Vibraplanes in my system improved bass extension, clarity and overall resolution.

 

[thedudeabides]

c) i very much like the idea of clamping the devices to the shelf to control the chassis resonances; i imagine e.g. a plate that you put on top of the device and then clamp with 4 threaded rods to the shelf, sandwitching the device

Cheers,

That's exactly what the Michael Green clamp rack does.

And the component is coupled to the bottom shelf with three Mapleshade trip point brass cones and one cone contact with the shelf above.

 

[cjf]

That's exactly what the Michael Green clamp rack does.

And the component is coupled to the bottom shelf with three Mapleshade trip point brass cones and one cone contact with the shelf above.

Maybe its just hard to see in the pic provided but I am not seeing anything that looks like a clamping of the components taking place in that rack.

 

[microstrip]

Look at the top of the preamplfier.

 

[PeterA]

That's exactly what the Michael Green clamp rack does.

And the component is coupled to the bottom shelf with three Mapleshade trip point brass cones and one cone contact with the shelf above.

Thedudeabides, that is an interesting rack. Thanks for sharing the photograph. I can conceptualize how both internal and external vibrations can be absorbed by the rack, but where do these vibrations go? What keeps vibrations from one component from entering another component? Do the vibrations entering the rack from the floor, the air, or from the components themselves have a path out into the floor and away from the components or are the vibrations just resonating the whole assembly in a kind of loop?

What are the shelves made of? Perhaps they act as a sink to absorb the vibrations from the components once they are drawn out through the clamping.

Can you describe how the sound changed when you switched to this rack?

 

[Rodney Gold]

All the vibrations in a room are air borne or originate from the speakers.. so ideally you want to isolate the gear from it .. how about putting the component you want to isolate into a soundproof enclosure?
Before dealing with these issue , play closely spaced test tones from 400hz downwards and trace and track those audible buzzes and rattles you hear and fix em .. you will be surprised at whats merrily singing along ...

 

[TBG]

In my experience there are two very effective moves to reduce the impact of vibrations-Stillpoint's using ceramic balls to convert vertical vibration into horizontal and then to convert it to heat and Star Sound Tech's mechanical coupling that gets vibration speedily to ground. I have treble choosing between the two. Certainly the Star Sound approach has gives a very sharp and real leading edge and great information about placement of the instrument and players. The realism of the sound stage is quite real.

The Stillpoints soundstage leads to pleasant music but not to realism. With the exception my turntable, I'm going with realism from what Star Sound gives you.

 

[thedudeabides]

Look at the top of the preamplfier.

Micro,

Can you provide a similar expanded photo of one of the three tri point cones "under" the pre?

Thanks.

 

[thedudeabides]

Maybe its just hard to see in the pic provided but I am not seeing anything that looks like a clamping of the components taking place in that rack.

The shelves are adjusted vertically (via the threaded rod) to provide a downward force on the single cone located on the top of the pre thereby "clamping" the component between two shelves.

You can't see it in the picture but the top cover of each component is "bowed" at the contact point of the single cone shown in Micro's enlargement.

The component under pressure will not move horizontally if you grab the sides and try to shift the component. Essentially, it's locked in place.

Hope that helps.

 

[Mike Lavigne]

The shelves are adjusted vertically (via the threaded rod) to provide a downward force on the single cone located on the top of the pre thereby "clamping" the component between two shelves.

You can't see it in the picture but the top cover of each component is "bowed" at the contact point of the single cone shown in Micro's enlargement.

The component under pressure will not move horizontally if you grab the sides and try to shift the component. Essentially, it's locked in place.

Hope that helps.

it seems that over time (1) the 'bowed' top and bottom plates of the gear chassis will deform and (2) further adjustment will likely be required to optimize the lock, and (3) the chassis panel will be harmed permanently. which might or might not be an acceptable trade-off.

in practice does this happen? or am I over-thinking it?

 

[thedudeabides]

Mike,

Have had this rack for some 15 years, probably more and my CDP for eight years and pre for four years. I've had to remove these components from time to time over the years to send gear back for repairs or to change the tube in my pre. Top cover "deflection" is perhaps 1/8" or so. The bottom plate does not deflect and is supported by a "triangle" of cones located at the outside edges of the piece.

I don't overly compress the top cover and check by trying to laterally move the component once locked. Once it is "secure", done deal.

To answer your two questions. No and yes.