Zu’s full-range nanotech loudspeaker drivers use pulpwood as a core material along with adhesives and nanometer engineered structural materials to create a very high performance driver membrane.
Why paper as a core? Because wood fibers have an excellent blend of strength, weight and damping for use as a dynamic speaker’s cone, the material is easy to work with and these fibers provide much greater service life compared to plastics, glass fibers and thin metal alloys. The wave dynamics in cones of loudspeakers that are being played loudly are intense and will rapidly break down the vast majority of fibers and plastics. With advances in nanometer engineered structural materials, it’s now possible to improve the wood fiber’s strength without hindering damping or performance over time.
Zu’s “nano sanctified” drivers feature a nano materials pallet developed to compliment and improve the wave dynamics of the paper cone:
- increased stiffness and shear
- increased propagation velocity
- better control of modes and damping behavior
While damping is improved, this improvement is not due to the properties of the materials. Rather, it is due to the reduced weight of the membrane compared to what was required without the use of nano material fortification. Zu’s nanotech cones are lighter than the previous generation. Better power transfer of waves-on-cone to waves-in-air results in reduced damping needs, as more energy is transferred from one medium (the cone) to another (sound in air).
Better strength and lighter weight gives you better dynamics and greater bandwidth, with less modal noise. Clearer, more extended, more dynamic, and natural -- simply better sounding sound.
Nanometer material pallet on first generation Zu nano doped drivers (ZuND/G1, sans engineering detail): ceramic spheres, fumed silica, cristobalite nanofibers. Application: Aerosol within a custom formulated epoxy matrix.
The above is an intended as an overview. The following dialogue is in response to customer inquiry on nano sanctification:
We didn't intend to to be vague but we think it's appropriate as the nano-level world behaves differently than the normal structural world. What's happening down there is rarely visible. Maybe this will all make more sense after additional explanation, so here goes:
The cone makeup is actually lighter by several grams compared to it’s predecessor, as we are reducing the need for other binders and damping compounds. We use epoxy so we can handle the cones safely and so that the nano infused matrix lays atop the fiber structure rather than penetrating it. The nanometer particles are so small that the bond with the material is via van der Waals force -- primarily depending on size, form, and materials.
Most of the time, nano structures are added to epoxies or vinyl-esters to help further strengthen the matrix of synthetic and organic high-performance composites -- such as graphite/carbon, Kevlar, glass, wood and other fibrous materials generally used in heavily engineered, close-mold, resin-infused products. Water is often used as a carrier on surface applications. However, in our case, the water swells the paper core considerably, and the particles are attracted/driven deep into the structure.
There are other problems with waterborne solutions relative to our application -- the natural fibers do not seal and there is lack of definition on the skin/core. We want more of a skin on the cone structure so the paper can continue to act as a good damping force. Only a portion of the energy is transferred to air and the loudspeaker’s surround, spider, frame, and cabinet cannot damp or transfer much wave energy.
Another reason for using epoxy as a carrier is that it makes it safe to spray. While there are other ways to apply it, the sprayable mixture works well for our application, tools, and level of sophistication.
For UV protection -- epoxy degrades rapidly from UV exposure -- we use UV absorbing compounds within the mix that rise to the surface of the skin, protecting the epoxy from the sun.
The matrix is so thin that it’s extremely difficult to see the difference between the old cone and the nano imbued cone, or nano sanctified cone. We like "sanctified". It's not so techy and we think it sounds cool, but that’s just us being fun
In the right light, the nano sanctified cone reflects/refracts light differently and has an odd distant shimmer to it. It's a bit like looking at the nearly starless, cloudy parts of the Milky Way on a dark night, in the middle of nowhere.
Zu’s “nano sanctification” ratios, epoxy compound, and UV protectants are not released.