Vibration isolation question

[rockitman]

Isolation Pads

marketed towards professionals for use mainly under monitors on meter bridges. Many companies make them the most popular being Auralex.

Are they like hygiene pads ?

 

[JackD201]

Nowhere near as absorbent and I bet nowhere near as comfortable

 

[DonH50]

Don,

Van dan Hul, a dutch manufacturer mostly known for his cables and phono cartridges, has developed audio measuring systems going down to -140 dBFS. He referred that this type of resolution is needed to study this type of "small differences".

Perfect, best to read their results then. I doubt many have the ability to measure vibration (or any) effects to -140 dBFS, and most techies would probably say artifacts at that level are far below the threshold of audibility. I would, but undoubtedly my ears and system have insufficient resolving power. Best to defer to people with the equipment to measure and able to hear the differences.

Thanks microstrip - Don

 

[Atmasphere]

Isolation Pads

marketed towards professionals for use mainly under monitors on meter bridges. Many companies make them the most popular being Auralex.

I had thought as much- not really related to high end audio.

We run monitors on our meter bridge in the studio, but we use Sound Anchors speaker stands designed for the purpose. They provide mechanical damping of the speaker cabinet, as well as adjustable height and compact installation.

Jack, what I think you know but Ethan apparently does not is that a proper anti-vibration platform of the kind that is really germane to this topic is usually a heavy device, and does not bear any resemblance to a pillow or a pad (both of which, if used, might provide isolation from the surface beneath but provides zero damping of the device perched upon it, IOW such vibration damping platforms can reduce vibration that is air borne).

An example might be the Silent Running Audio platform (http://www.silentrunningaudio.com/products/ohio_class_isobase.htm#plus)

or the Symposium platform: http://www.symposiumusa.com/svelte.html

Funny thing is, if you google 'vibration damping platform' you can view many images **including measurements** showing the effectiveness of such platforms for use in all sorts of applications, not just audio.

FWIW the table on which my LP mastering lathe is perched has a set of adjustable 'tip toes' and the lathe itself has a further set. Between the lathe and the table is a vibration-damping platform built for the lathe; the whole thing was built in the late 1940s or early 1950s. Tip toes are not a new idea! Professional (in fact, actually professional and not faux professional) audio has been aware of the benefits of mechanical damping for a very long time. If you look inside the electronics of an Ampex 351 tape machine, you will see a damping/isolation system for the circuit boards. The electronics were designed in the late 1950s.

 

[treitz3]

Ethan,

to be frank and based on the consumer level of equipment (AV receiver, cd player ect) you choose to own, I don't think isolation would be helpful for your system. The resolution and transparency is just not there, thus I understand why you wouldn't get an improvement. For the rest of us who choose to assemble a much more resolving and transparent to the source system, isolation matters a lot.

Ed Zachary.

Tom

 

[JackD201]

I had thought as much- not really related to high end audio.

We run monitors on our meter bridge in the studio, but we use Sound Anchors speaker stands designed for the purpose. They provide mechanical damping of the speaker cabinet, as well as adjustable height and compact installation.

Jack, what I think you know but Ethan apparently does not is that a proper anti-vibration platform of the kind that is really germane to this topic is usually a heavy device, and does not bear any resemblance to a pillow or a pad (both of which, if used, might provide isolation from the surface beneath but provides zero damping of the device perched upon it, IOW such vibration damping platforms can reduce vibration that is air borne).

An example might be the Silent Running Audio platform (http://www.silentrunningaudio.com/products/ohio_class_isobase.htm#plus)

or the Symposium platform: http://www.symposiumusa.com/svelte.html

Funny thing is, if you google 'vibration damping platform' you can view many images **including measurements** showing the effectiveness of such platforms for use in all sorts of applications, not just audio.

FWIW the table on which my LP mastering lathe is perched has a set of adjustable 'tip toes' and the lathe itself has a further set. Between the lathe and the table is a vibration-damping platform built for the lathe; the whole thing was built in the late 1940s or early 1950s. Tip toes are not a new idea! Professional (in fact, actually professional and not faux professional) audio has been aware of the benefits of mechanical damping for a very long time. If you look inside the electronics of an Ampex 351 tape machine, you will see a damping/isolation system for the circuit boards. The electronics were designed in the late 1950s.

I use all Critical Mass Systems myself Ralph. I had done A LOT of experimenting before I ended up with these. I was DIYing all sorts of stuff.

 

[Ethan Winer]

I don't think isolation would be helpful for your system. The resolution and transparency is just not there, thus I understand why you wouldn't get an improvement. For the rest of us who choose to assemble a much more resolving and transparent to the source system, isolation matters a lot.

Of course! My audio system is not nearly as good as yours. My inferior gear muddles the sound so badly that the small but real improvement from special wires and isolation products won't make any difference.

I see in your profile a bunch of expensive stuff, but no mention of acoustics or even photos of your space. Have you ever measured your room to see the reverb decay and reflection arrival times? Are you certain your system is more "revealing" than mine?

--Ethan

 

[thedudeabides]

Of course! My audio system is not nearly as good as yours.
--Ethan

The classic, self serving retort.

And denial of the obvious fact that a more transparent system (gear, acoustics, etc.) will allow one to more easily hear things that a less transparent system will not.

And that certainly includes vibration attenuation devices.

DUH!

 

[mauidan]

I see in your profile a bunch of expensive stuff, but no mention of acoustics or even photos of your space. Have you ever measured your room to see the reverb decay and reflection arrival times? Are you certain your system is more "revealing" than mine?

--Ethan

See:
http://www.whatsbestforum.com/showthread.php?15540-Wilson-owner-since-2010

He seems to own a lot of your products.

 

[Ethan Winer]

He seems to own a lot of your products.

Well, I stand corrected and apologize for that. But still, I do not accept the claims of vibration products without proof.

rockitman, you're close enough that it would be worth a trip for me to visit you in person and test some of this stuff. Are you game?

--Ethan

 

[DonH50]

With a swept sound source and spectrum analyzer it's not too hard to measure the sensitivity of components to isolation. I didn't need 140 dB dynamic range for that way back when I tested audio components but have not done anything like that in many years. Finding my results would be an exercise in futility; probably tossed in one move or another. The debate, as always, is what level of isolation is needed to render any vibratory components inaudible.

It was easy to measure, even 20 - 30 years ago, the sensitivity of most components to vibration. The only components routinely found to pass the audibility threshold of listeners were turntables and sometimes a tube device, particularly with a bad tube. Speakers, maybe, I do not recall if we obtained conclusive results. Cabinet radiation tended to swamp other vibration sources and it was fairly easy to show how some cheap speaker cabinets caused audible'ish distortion. Almost all the time vibration-induced distortion was masked by the music, but even though the systems were high-end, it was long ago so most would say not relevant to today's technologies.

This seems like another open-ended debate.

 

[thedudeabides]

See:
http://www.whatsbestforum.com/showthread.php?15540-Wilson-owner-since-2010

He seems to own a lot of your products.

How embarrassing. Another example of shooting first and asking questions later.

 

[PeterA]

I use three Vibraplanes, preloaded with 136 lbs of steel ballast plate, for each of my Solid State amplifiers and for my turntable. I was astonished that it made such a big difference under the amps and surprisingly, the steel ballast plates were almost as significant as the Vibraplanes themselves. The Vibraplanes are more effective if supporting close to their maximum design load, in this case 275 lbs. The SME turntable is already suspended but the added isolation and the placement of the motor controller on the isolation made a significant improvement. The noise floor dropped, bass definition, extension and resolution improved as well as overall clarity. This was the case with both turntable and amps. Photos below:

 

[BlueFox]

A less expensive method for vibraton isolation is to use Mapleshade Micropoint Brass Footers on all electronics, even power conditioner. As I added a set to each piece the sound cleared up. After installing a Mapleshade Samson v.3 4 shelf rack (500 pounds of solid maple, and steel legs), it really reduced vibrations.

As an experiment, I used to remove my DAC from the brass footers, but then the sound would get muddy, for lack of a better word.

 

[thedudeabides]

A less expensive method for vibraton isolation is to use Mapleshade Micropoint Brass Footers on all electronics, even power conditioner.

Agreed. I use the same product (single point version versus micro), in conjunction with the "Michael Green Clamp Rack" on all my components, and am very happy with the results.

 

[Bill Stevenson]

Don,

Your post prompted some memories that I had forgotten. Back in the 1970s, I sold what was then high end equipment. Speakers such as JBL, Altec-Lansing, Bozak, Klipsch, and electronics such as Audio Research, McIntosh, Marantz, and SAE. Rudy Bozak came to our store for a meet and greet and among other things we visited a client who had a purpose-built sound room with infinite baffles built to Rudy's specifications housing the full Bozak Concert Grand complement of drivers. The chamber holding all this was made of brick. Rudy Bozak said that any speaker cabinet vibrates and will affect the overall voice of the speaker system. An infinite baffle that is properly designed and built will have less effect, but not zero effect. The designer of the new Sony SS speakers said much the same thing during an interview at the launch of these new Sony statement speakers last year. I can assure you that the brick housing infinite baffle system sounded markedly better than the Concert Grands at our store or the pair in my own home.

Bill

 

[Atmasphere]

Back at the 1991 or 1990 CES, I saw a set of MG-3's that were modified by George Cardas. The mod was a new frame for the speaker, built of carefully fitted sections of wood, laminated together in such a way that if one bit resonated, it could not talk to its neighbors as they resonated at different frequencies (Empire used this principle in the platters of their later turntables back in the 60s and 70s). It was really remarkable how much better the speaker played bass as compared to the stock speaker- it literally could shake the room while the stock speaker had no chance. It was an excellent example of how reducing vibration in the speaker could yield some impressive results!

 

[DonH50]

Hi Bill: I only met Rudy once or twice but he was very nice to a green kid. One of the dealers I worked with sold Bozak. Around that time (early 80's) B&W was showing how their new Matrix line reduced cabinet resonances by using laser interferometry. It was pretty cool... My personal experience has been mixed, with what appear to be pretty bad cabinet ringing not being audible, though in some cases there was a clear improvement when it was removed. Many times you could hear it with test tones but not with music, much to the dismay of some of our golden ears (myself included at that time). Other times, the right music would drive you nuts once you knew what to listen for. Of course, for me, it's a short drive. We installed some infinite baffle designs, and I'll just say an improperly braced wall is an excellent way to demonstrate how "cabinet" resonances can really hose the sound!

Atmasphere: I have tried a bunch of Maggie mods through the years, including a number of stands and frame mods. I have heard bass increases similar to you describe after a frame or stand mod, but then taken the same pair to a different room and it was virtually inaudible. Or not. This is probably not the right thread, but there are a lot of variables with planer speakers and I found it tough to isolate them (no pun intended). That said, virtually every time we braced the panel (Maggie or ESL), the measured impulse response improved. Other improvements tended to be influenced by their interaction with the room. Put them in the right (wrong) place in the right (wrong) room and the sound waves buffeting the panel cause all sorts of mayhem. Bracing would reduce but not cure that problem. I found going to spiked feet on a carpeted floor, or otherwise coupling the frame to a solid floor, would improve bass noticeably in most situations using sighted or DBTs. Starting from that point, or with the feet already solidly coupled to the floor (some actually screwed them down with lag screws), adding a heavy frame or brace did little if anything more. In some cases, I think the extra mass of the rebuilt frames benefited the speaker. That whole exercise is one I'd love to repeat today.

There was one speaker that had a thin cabinet way back then that was highly regarded, until people found out the cabinet was a significant part of the sound, and not always in a good way. Can't for the life of me recall what it was, but the B&W team that toured used their setup on the pair we had in stock and it was like a light show.

 

[Atmasphere]

^^ Back then I remember a speaker company called Maverick that made a little monitor. Upon learning how the cabinet could cause coloration, they went about deadening it, only to find an unacceptable loss of bass

 

[Ethan Winer]

How embarrassing.

Not nearly as embarrassing having people know you spent $628 each for power wires.

http://www.audiolab.com/Cardas_Golden_Reference_Power_Cord_Each_1_5m_4_p/cargrpc.htm

Okay, now I'm done.

--Ethan