Footers under my speakers double the perceived value of my speakers!
hg, yours are a perfect example of a floor stander that could accept Townshend Audio seismic pods, however with the bolt on top like the seismic corners have, then you can bolt them directly under your outriggers. Zero Stiffness is the goal. There's a reason springs are used under cars, buses and trucks and not Gaia. However the springs are so pliable that for example outriggers are generally required. The Gaia are not as compliant. It is the effect of compliance that will allow the greatest of isolation to take place. |
If you have a suspended floor with standard joists, and you use an efficient isolation system there is something I’d like to share that I became aware of. The suspended mass will cause some compression on the floor joists, and when there is energy against the isolation system, it will also cause the flexible floor to accept a portion of the energy. (foot falls, and speakers being major culprits) The floor, and the isolation device of choice will share the energy between them, proportional to their spring rate or Young’s modulus. The best results I have found is by using as close to a zero stiffness (in my case wire springs) device on a very rigid substrate, where the substrate doesn’t easily deform and the energy is mostly controlled by the isolator. What is zero stiffness? This is the easier concept to digest that I could find, "a zero stiffness structure maintains a constant potential energy, which is continuously redistributed as the structure deforms, thus eliminating any preferred position under the applied load or self-stress." Spring steel with an engineered geometry (a manufactured spring) is one of the most efficient means of achieving this. It is the most popular device used in platforms used under electron microscopes and imaging devices used in science and medicine today. 4Hz isolation devices using passive technology use varying types of spring structures. The goal is to hold the load, but also have the ability to accept and change shape from vibration at the minutest amount and smooth out a broad range of both frequencies and amplitudes of those frequencies - just like springs used under vehicles of every type. Mass loading under a sprung system on floor joists may help compress by loading the floor and reduce it’s percentage of the vibration sharing, pushing a higher percentage of the energy into the isolators (preferably springs), thus performing more of the work. The smallest amount of energy that is possibly isolated with the broadest range of frequencies and amplitude is going to work best on as rigid a base structure and a rigid object that is being isolated. The isolated object should move easily on the device it’s isolated upon, if not easily moved, like a bobble head toy, then you know it’s not flexible and also not as isolated as it could be. www.minusk.com |
@audiopoint - I don't want to leak information from my former employer that isn't already well known or certainly available from other vendors quite well known and represented here in the forum, or available on his website. In response to your use of "brass and copper alloys at a 5/16” thickness". Copper for example has a Young's Modulus that simply is superb for baffle material on the tweeter drivers them self. If I were in a position to manufacture high end audio, I would certainly be using copper baskets to attenuate ringing of the speaker basket. Brass is one of I think about 400 copper alloys? I would certainly search for an alloy of copper if you were to continue or rather resume research. So I might as well name drop so we know where I am getting my information from. I used to work for Mike Lenehan in Australia, so the devices he uses are specific to his loudspeakers. Essentially his loudspeaker designs use spring steel plates laminated to the top, side walls and baffle of all of his later designed speakers, these were connected electrically like a ground plane, not unlike a Faraday Cage, whilst simultaneously creating a more rigid enclosure. Cross bracing he uses I cannot divulge too much, however as he has it listed on his website and other places, I can tell you that he does use silicone filled rigid copper tube as well as cast iron rod as cross braces. Interesting that you also researched similar materials **I think if you want to know more regarding this, you might want to contact Mike Lenehan of Lenehan Audio directly** Mike does get a significant tax break for the research he does, and has to report to the Australian Government each tax year. Making a more rigid enclosure doesn't entirely remove resonant frequencies of the cabinet, it simply moves them to different frequencies, as I suspect you well and truly understand from your comments. Mike used the sacrificial method of leaving the back and bottom of his loudspeakers without the extra rigidity of the sprung steel plates. This is to release the energy in a manner that least affects the sound field being voiced by the speakers. However in moving the resonant frequencies towards either less important bandwidths or preferably outside audible spectrum of frequencies, you are simply modifying the energy, channeling it where it can do least harm. With the acknowledgement that the cabinets are specifically designed to integrate well in an isolation system that attenuates energy from under the loudspeaker; you understand that in Lenehan Audio's design it is no accident that it works exceedingly well. However in not so inert cabinets, the effects of isolation may have even a greater effect on improving the sound. Since then, I have tested spring isolation on other loudspeakers, even one in a hifi store in El Paso, where I placed springs under the amplifier, and source electronics. I then placed it under the best floor standers he had in the store. After listening he excused himself and introduced two of his techs to hear what $20 worth of Smalley's wave springs from Ebay just did to the sound. That's when the questions really started coming - after you hear it, and there's no mistaking the improvement. USE SPRINGS WITH CAUTION When you truly float your speakers on isolation, you should be able to move them (regardless of weight) with your pinky finger. If they are rigidly mounted they are NOT nearly as isolated as they aught to be for maximum isolation, and sonic improvement. Speakers, especially floor standers will become compliant to forces in all three axis, which means the center of gravity can be easily moved across and over the base. Townshend Audio use outriggers, to broaden the base to account for this. I highly recommend anyone placing springs under their speakers to broaden the base of the speakers!!! Whatever approach you use, or product, if your speakers are not compliant with a tiny amount of gentle force - they are not zero stiffness. For better results than I am putting forth with tuned spring isolation, please research quasi zero stiffness. If any of you are interested? on my system page, the easiest way to see speakers on wave springs, the copper colored pair are sitting on Smalley wave springs. You will see the gap and shadow under them above the heavy stands. The first image you can see a shadowline under my sub, it is on compression springs, as is my amplifier and source. https://systems.audiogon.com/systems/8721 |
@fsonicsmith the Gaias I suspect are more rigid than springs in a zero stiffness tuned loaded spring rate for >10Hz isolation? I for example would NEVER place 4 correctly loaded springs under your Devore O/93 where the spikes would be placed. WHY NOT? Because broad frequency isolation requires compliance in the device suspending your speakers. The center of gravity with little force could easily move towards the limits of your base on those speakers, making them liable to topple over if you bumped them. The very fact that the IsoAcoustics can safely hold your speaker up without compromising the safety of them is an indication they are not compliant enough to fully isolate them. Both the frequency and amplitude of the frequency needs to be accounted for in isolation. I don’t know what vehicle you drive, however I’d bet you can grab a wheel arch and without too much effort lift it a quarter inch by one arm?? Consider how much your vehicle weighs and how compliant the suspension is, even with that immense load. It is the compliance to even small energies in higher frequency, and larger amplitude at low frequency and up that make for good speaker isolation. I would broaden the base upon which the springs are set to move the edge away from the center of gravity - just like Townshend Audio does. |
