New Invention To Revolutionize Low Frequency Acoustics
Posted: Fri May 25, 2018 7:57 pm
Here is a, brand new, idea that promises to revolutionize low frequency acoustics, not in ten years from now, but hopefully by next year.
The idea is to use something called "negative-stiffness" (google it!) to create a product that is twenty times more compliant (compressible) than gas (air), thus making it possible to either absorb, or reflect, a staggering twenty times more low frequency sound
E.g. it can be designed to absorb twenty times more than the high quality bass traps of today, because bass traps are generally limited by the compliance of an enclosed body of air that must contract and expand. Resonators use resonance to increase these contractions and expansions, however this product can be as affective as a resonator, but on all frequencies simultaneously.
Also when placed between floating panels, inside of hollow ceilings or walls (or floors), its high compliance will completely isolate the panels from each other, i.e. it can cause a two-inch gap to become as effective as a forty-inch air gap (this can correspond to giving you an extra 26dB efficiency, which could otherwise only be achieved by making the wall twenty times heavier).
Another unique feature of this invention is that, unlike a wall, it can reflect the low frequency sound without needing to fill up an entire plane, i.e. it can help block the low frequencies from going out the window or doorway, without actually blocking the window or doorway, the reason for this is that it uses low impedance to reflect the sound, while walls use high impedance, and since the sound takes the path of least resistance the sound will be attracted to it and then get reflected, where as a wall will simply cause the sound to be attracted to the window or doorway which have the lower impedance. This is also why this product works so well with walls, because when they are combined they create an extreme impedance mismatch which results in extreme reflection.
SO WHAT'S IT MADE OF? The final product will comprise a negative-stiffness mechanism that cancels the stiffness of air inside of a container, or bladder made from thin materials (which have a high young's modulus), the internal air pressures need never go above 0.1 psi so it can be made thin and light,
However, unlike most negative-stiffness mechanisms, the negative-stiffness mechanism used for this invention passes all the criteria: it’s very quiet, very precise, very durable, and very light. This, as well as other critical features that make the idea practical, are patent pending.
Note that negative stiffness works great for the above mentioned applications, but it remains impractical for use in sealed sub woofer boxes (i wasted half a year trying to make it practical).
This product may also be in high demand on aircrafts, because it can be made very light weight (it can also allow for light wall panels) and it can accommodate slow pressure changes in a unique way.
Although this product can be as effective as active noise canceling equipment, its parts are very simple, and it may function on its own for a lifetime without needing a battery charge, i.e. it may use several microwatts.
All of the problems have already been solved, e.g. how the final product will handle barometer, and temperature, changes, as well as problems arising from the fact that air in an adiabatic process is stiffer than air in an isothermal process.
I do not have the financial resources to bring this idea to market, so I am trying to get this idea out there, so if you happen to know someone with an advanced degree in acoustics that may corroborate my claims please bring it to their attention, and if this person works for a major company, perhaps sound related or aircraft related, that would be even better.
Best regards,
Michael
The idea is to use something called "negative-stiffness" (google it!) to create a product that is twenty times more compliant (compressible) than gas (air), thus making it possible to either absorb, or reflect, a staggering twenty times more low frequency sound
E.g. it can be designed to absorb twenty times more than the high quality bass traps of today, because bass traps are generally limited by the compliance of an enclosed body of air that must contract and expand. Resonators use resonance to increase these contractions and expansions, however this product can be as affective as a resonator, but on all frequencies simultaneously.
Also when placed between floating panels, inside of hollow ceilings or walls (or floors), its high compliance will completely isolate the panels from each other, i.e. it can cause a two-inch gap to become as effective as a forty-inch air gap (this can correspond to giving you an extra 26dB efficiency, which could otherwise only be achieved by making the wall twenty times heavier).
Another unique feature of this invention is that, unlike a wall, it can reflect the low frequency sound without needing to fill up an entire plane, i.e. it can help block the low frequencies from going out the window or doorway, without actually blocking the window or doorway, the reason for this is that it uses low impedance to reflect the sound, while walls use high impedance, and since the sound takes the path of least resistance the sound will be attracted to it and then get reflected, where as a wall will simply cause the sound to be attracted to the window or doorway which have the lower impedance. This is also why this product works so well with walls, because when they are combined they create an extreme impedance mismatch which results in extreme reflection.
SO WHAT'S IT MADE OF? The final product will comprise a negative-stiffness mechanism that cancels the stiffness of air inside of a container, or bladder made from thin materials (which have a high young's modulus), the internal air pressures need never go above 0.1 psi so it can be made thin and light,
However, unlike most negative-stiffness mechanisms, the negative-stiffness mechanism used for this invention passes all the criteria: it’s very quiet, very precise, very durable, and very light. This, as well as other critical features that make the idea practical, are patent pending.
Note that negative stiffness works great for the above mentioned applications, but it remains impractical for use in sealed sub woofer boxes (i wasted half a year trying to make it practical).
This product may also be in high demand on aircrafts, because it can be made very light weight (it can also allow for light wall panels) and it can accommodate slow pressure changes in a unique way.
Although this product can be as effective as active noise canceling equipment, its parts are very simple, and it may function on its own for a lifetime without needing a battery charge, i.e. it may use several microwatts.
All of the problems have already been solved, e.g. how the final product will handle barometer, and temperature, changes, as well as problems arising from the fact that air in an adiabatic process is stiffer than air in an isothermal process.
I do not have the financial resources to bring this idea to market, so I am trying to get this idea out there, so if you happen to know someone with an advanced degree in acoustics that may corroborate my claims please bring it to their attention, and if this person works for a major company, perhaps sound related or aircraft related, that would be even better.
Best regards,
Michael