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SKU: aaa-cms-Sotto Voce Category: Tags: ,


“This is a rack you can buy and live with happily ever after.  Or, when fortune smiles, you can upgrade to your heart’s content.”   Alan Taffel, The Absolute Sound, Issue 249

In the Sotto Voce wood rack, CNC’d solid aircraft aluminum hardware is integrated into rift cut quarter sawn Sapele hardwood architecture to move energy in a purposeful manner closely mimicking that of our metal architectures.


Sapele was chosen for its aesthetic beauty and its interlocking grain pattern where fibers twist around the tree as it grows canceling out movement typically found across the grain.  Its 1510 Janka rating (circa US and Brazilian Hard Maple and African Walnut), and its rift cut are mandatory to minimize energy storage in the superstructure.


Sotto Voce was designed so that user-friendly shelves can adjust up or down with minimal effort.  


Sotto Voce is synonymous with “mechanical stability and user flexibility”.  An owner can further raise its performance at any time for any component as budget allows and performance and value align with each upgrade.  Upgrades to RiZE! footers and all of our filters including Black Sapphire MK3, Black Platinum MK3 and Black Diamond MK3 can mix into any of the vertical tiers of the rack to elevate the performance of a component to even extraordinary levels.


Critical Mass Systems chooses specific metals used for its rack architecture with respect to their elastic modulus and thin rod speed to ensure even energy transfer throughout the rack architecture thus transferring vibration into the filter systems at predictable frequencies and velocities.  This greatly reduces energy spikes that can otherwise propagate through the filter systems and degrade the performance of electrical circuitry and mechanical devices such as turntables and transports causing audible degradation of the output signal.

Elastic Modulus is a mathematical description of a substance’s tendency to be deformed elastically when force is applied to it. The elastic modulus of an object is defined as the slope of its stress-strain curve in its elastic deformation region: as such, a stiffer material will have a higher elastic modulus.  The elastic modulus of a material is directly related to the degree to which it propagates and/or reflects energy as vibrations are applied to it.  Critical Mass Systems uses high purity metals in the construction of its rack architecture with Elastic Modulus as follows:

  • Vertical legs and horizontal side supports are quarter sawn rift-cut Sapele with a Janka rating of 1510.
  • Vertical shelf supports and horizontal front and back supports are high purity (96% to 99%), solutionized, stress-relieved, stretched and artificially aged aluminum alloy – 10 X 106 psi (69 GPA), with a thin rod speed of approximately 5,014 m/s.
  • Spikes are high purity (99%) titanium alloy – 15 X 106 psi (105 GPA), with a thin rod speed of approximately 5,090 m/s.

The thin rod speed of sound is the speed energy moves through a material and is dependent upon its atomic and molecular constituents.  The speed of transmission of sounds waves (longitudinal and transverse) in metals depends on the mechanical properties of the metals.  High modulus metals allow the transmission of mechanical energy at high speeds. Shear waves propagate at speeds governed by the shear modulus of the material. Depending on the material, these can be very different speeds.  If you think about it, elastic modulus and thin rod speeds explain why the old adage, “everything does something”, is true.



Critical Mass Systems

Please Contact Us for Configurations and Pricing.
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