Background vibration and your system.

Fascinating.  At one point I lived in an old wood framed house in Indianapolis about 12 miles from the airport and a half mile from the interstate.  The passing of heavy trucks over a short overpass bridge on I-65 was something you could hear and sometimes feel inside the house.  It made me think that planes landing would also cause an impact on the house, although I never directly detected an event.

My basic defense against external vibration has evolved to sheets of cork and rubber like materials.  For the turntable I use a Black Diamond Racing platform and a ball bearing cup device (can't remember the brand name).  I don't have footfall problems, but I have no idea if what I use is better or worse than alternatives.

I never understood hard footers.  The company I retired from does quite a bit with vibrations related to construction activities as well as background readings and we designed suspension/damping systems for machinery and in one case for auditorium balcony seating where resonant oscillation was a concern when the crowd would stamp their feet in unison.  In most cases, the problem was modeled as springs and dash pots so the solution was a form of damped spring, or an elastomer. I suspect the same thing works for audio equipment with one goal being to dissipate resonant energy occurring in the audible frequency range - think Townshend’s platforms with damped springs for support or any of the elastomeric solutions.  Mass loading could help too.  I suspect there may be some papers you could look at related to the seismic effects on sensitive instruments or maybe on audio equipment.

Very cool, I have often wondered how much background vibration exists in my area. I knew I NEEDED those Stack Auva’s I bought for my DAC. Thanks for sharing. 

@mitch2 

The soft footers I’ve tried have resulted in compressed sonics and rolled off highs. Which do you recommend?

That seismic info is very cool.  There's no doubt vibrations are bad.    I have used Auralex Sub Dude isolation platforms under every sub I've used or installed for the past 15 years or so.    They make a huge difference.   

I love science and interesting to note what vibrations are happening where.

What disappoints me overall is that very little evidence based research into the value of vibration mitigation in audio equipment has been done.

I used to have a RadioShack phono preamp. I could physically tap the case and hear the ringing in my speakers.  So, OK, that particular piece of gear was probably vibration and microphonic. 

However we do precious little to assess this for any other solid state gear, or tube gear for instance.   Seems straightforward research to do in this day and age.

How hard is it to measure the output of a DAC with and without outside noise being induced?  So many ways this could be tested, and crickets.

Wonderful post (I am also a geologist). Some of the biggest benefits to my stereo system were through vibration control. My HiFi Racks rack with two inch oak shelves and point plate isolation made an astounding improvement, as did Stillpoints under my source compnents.

George, you might be interested to learn that the Scanning Electron Microscope on the JOIDES Resolution drillship was originally isolated from the custom wooden lab bench by an inner tube suspension. Vibration control for a number of the instruments and microscopes aboard that ship during the Ocean Drilling Program and the two later IODP programs was always a challenge! My favorite problem that was addressed was how to do high precision weighing on a moving ship!

@jallan 

Thanks for your interesting post. Great problem... I love challenges like that. Sound like fun.

You know Silent Running Audio... started with platforms for scanning electron microscopes and submarines? I don't know that much about them, but love their platforms. 

Just went on the Silent Running website-what an interesting company! The most recent picture of the JR SEM (before it was demobilised last year) showed the SEM on cork+rubber isolation feet on top of what looks like an isolation platform, not si dissimilar but thinner to the cheaper Silent Running platform. I wish that I knew of the company earlier (several decades ago I had oversight of the JR labs, and for nearly two decades I oversaw funding of JR operations at NSF), as I could have suggested them to Texas A&M (as science operator of the JR). 

@erik_squires - There has been research resulting in useful products like those from Townshend, SRA, and other companies that many here benefit from. The most prevalent applications have probably been in mitigating vibrations acting on turntables.

On the flip side, IMO there are also products marketed using pseudoscience and/or exaggerated claims, which muddy the water.  As you indicate, the absence of documented research has left the audio equipment industry without consistent/uniform vibration measuring processes and baselines.

Regardless of the application, the principles are consistent and solutions involve various implementations of mass, springs, and damping as presented in this link and this link.  However each application is unique depending on what is being isolated, and from what vibratory source.

In our audio world, springs are successfully used like Townshend platforms or the inner tube discussed earlier, which is an air spring.  Commonly used elastomeric footers are also a form of damped spring. Many audiophiles mass load with brass or other materials, and many types of turntable stands and platforms seem to be successful at mitigating the effects of vibrations. However, without clearer documented research and guidance it is mostly a trial and error endeavor in the audio world.

There is a pretty cheap fix for vibration actually.

Low durometer (about 30) sorbothane pucks...There's a website out there for correct weight distribution on it. Yes,  it will stick and stain if you don't do the following....get a plastic bag, cut 2 pieces of the plastic out of it and sandwich the sorbothane puck between..to prevent staining, etc...Works way better than some vulture priced crap.

I've noticed some big improvements on dacs.

if the tremors  caused settlement/foundation issues, etc, you have other bigger problems besides hifi to worry about, of course.

@deep_333 - I switched from spikes to Herbie’s products, to damped springs and then to these platinum silicone elastomers, which can be easily sized for the equipment or speakers being supported. The springs worked great but the silicone elastomers (I believe at duro 20) provide most of the benefit with improved user convenience, IMO. YMMV

@mitch2  +1

check this out...can’t find the whole vid.

"are clock crystals sensitive?"

https://www.youtube.com/watch?v=suFmFmlZdtc

the best thing one could do really is to ’float things’ on some thick low duro jelly squishy elastomer whatever.

A lot of the stupid stuff that gets sold for hifi ’isolation’ didn’t do anything for the likes of what you saw in this vid. 

@mitch2 I’ve seen research on the reduction of _vibration_ with a variety of devices.  What I have never seen is research on how susceptible a given device is to vibration. 

For instance, put a DAC on a very shaky rack.  Measure the performance.  Now do the same with 110  dB of music playing in a room with a wooden floor. 

I use music as just one example.  If you have a vibration pad where you can simulate shaking at a variety of frequencies and amplitudes that’s fine too, but show me how this DAC starts to become microphonic or distort based on that vibration.

If anyone has links to that kind of research please @ me and let me know.

You can really knock yourself out comparing vibrapods, all the different elastomer pucks, cones of different materials... etc. I have a couple drawers of this stuff. I spend probably hundreds of hours or more doing detailed comparisons over the decades.

A very generalized conclusion I came to is that the very expensive stuff... like Townsend, Silent Running Audio, and Black Diamond work better than cheap stuff. It’s really simple, companies like these that do Research and Development can/must produce products that are very notably superior to someone who simply chooses a substance and makes it into a form. Companies like Townsend and Silent Running have outstanding reputations for a reason. Folks that can afford them hear the difference. 

I was young and poor once and worked my way through inexpensive alternatives. Nothing wrong with that. 

Many manufacturers take their own stab at resolving possible issues for their own gear. I say possible issues since every system location is different with different external influences, like flooring type, size and support of nearby speakers, rack and support conditions, nearby traffic, and more. The manufacturer can only do so much but some do try like SMc Audio and their gravity base (large brass plate with components anchored directly), and the many that use elastomeric stand-offs, applied damping materials, constrained layer damping, special coatings, and the wide variety of compliant footers.

For a time, I used spring supports under all my components and speakers.  I have found that paying attention to solid rack support, platforms like Z-slab constrained layer shelves and the black diamond shelf, and compliant footers has worked well in my system.

Fascinating topic and I checked my location very little seismic activity here in DC it would seem. That said I've had positive results from footers. Currently using Gregitek Aries footers under my preamp not much else. Amps are on a BBA ash board and that seems fine.

Nearly all new high end studio monitors are internally powered, clearly there is no vibration problems inside the speaker with the amplifiers and digital circuits. Why is there such a vibration problem later on down the line in the playback chain? Many new high end audiophile speakers have internal amps, DACs and other circuits there is no problem with vibration causing distortion in these units either. 
If someone is comparing tube equipment or microphonic unbalanced equipment sure vibration will affect the music. If there is a turntable in the room the sound itself at high SPL with cause problems. There are no magic feet that will take the power of direct sound waves out of the air. 

I have 2 DHT pre-amps.  I can tune my system by changing what’s under them.  It’s   Cheaper then rolling tubes but a little time consuming. I can add reverb which is nice with acoustic music.

I plan to use Center Point footers.

Studio monitors have a very different purpose and setup. They are made for near field listening and not for nuanced wide soundstage projection. Audiophile system are far more sensitive to inputs. I am sure if you took two self powered studio monitors and put them on stands in a listening room and fed with audiophile sound feed... well, that would be a whole different sound entirely. 

Isolation of what component are you referring to? speakers? clunker amps? If so, do your townsend or whatever.

I was specifically referring to dacs with the linked vid. After trialing everything including things that may have been priced as much as your speakers, yes, i decided at one point that these elastomers were the way to go, if deployed correctly for weight.

These guys did a lot of R&D, huh? Did you see their R&D facilities (a garage maybe? or something bigger) perhaps? test equipment? data? anything?

You can really knock yourself out comparing vibrapods, all the different elastomer pucks, cones of different materials... etc. I have a couple drawers of this stuff. I spend probably hundreds of hours or more doing detailed comparisons over the decades.

A very generalized conclusion I came to is that the very expensive stuff... like Townsend, Silent Running Audio, and Black Diamond work better than cheap stuff. It’s really simple, companies like these that do Research and Development can/must produce products that are very notably superior to someone who simply chooses a substance and makes it into a form. Companies like Townsend and Silent Running have outstanding reputations for a reason. Folks that can afford them hear the difference. 

Not exactly young and starving, but, I will always accept donations and free gear from very rich cats like you. 

I was young and poor once and worked my way through inexpensive alternatives. Nothing wrong with that. 

I have Isoacoustics on most of my equipment and speakers and those washing machine rubber isolators on my amps. Until now, I’ve never heard of Silent Running Audio,  but maybe they have something for my eighty pound amplifiers.

I agree that the entire vibration issue goes out the window with the use of powered speakers, many of which sound great. I prefer passive speakers so I can choose the amplification I want to hear (I bounce between a single ended tube amp and a Pass XA-25...efficient speakers), but that's just me. I do stick vibrapods under some stuff but I don't think it matters much (it keeps things from moving around when a button is pushed), but spending thousands on "special" gear racks and fretting about vibration infecting your precious gear pile seems like a waste of time and money. Vibrations are part of life and stopping 'em might mean you've just died.

A lot of people remark that their system sounds better at night and attribute this to less mains noise. But the complementary conjecture is that there is a lot less traffic activity at night - in urban environments anyway and so a lot less low frequency vibration.

As a separate point, a lot of the discussion is predicated on external vibration, but most components have internal vibrations too so both need to be controlled.

@yoyoyaya 

+1