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Wall STC Comparison

Sound Transmission Class (STC) is a single-number rating that measures how well a building element attenuates airborne sound. Higher STC values mean less sound passes through -- an STC of 50 renders loud speech barely audible, while 60+ provides studio-grade isolation.

Wall Constructions

Click any bar to reveal its cross-section detail.

STC Rating by Wall Type

Wall Cross-Section

Doors & Openings

Doors are the weakest acoustic link in any isolation chain. Every door in the complex is rated and sealed with acoustic gaskets.

Door STC Ratings

Observation Window

Control Room to VO Live triple-pane construction with 5-degree tilt to prevent standing waves.

Triple-Pane Assembly

50
5-degree tilt
80 x 50 cm opening
LayerSpec

Why Triple-Pane?

  • Three panes of different thicknesses (6mm, 10mm, 8mm) avoid coincidence resonance
  • Two air gaps at different widths (100mm, 75mm) prevent standing waves between panes
  • The 5-degree tilt eliminates flutter echoes and reflections back to the microphone
  • Laminated middle pane provides maximum mass and damping at the center of the assembly
  • Total air gap depth of 175mm gives excellent low-frequency isolation
STC 50 Spec

Full Comparison Table

All isolation elements sorted by STC rating, with construction details and pass/warn/fail indicators.

Element Type STC Thickness Key Materials Notes
Design Principles

Mass-Air-Mass & Viscoelastic Damping

Mass-Air-Mass Principle: Two massive layers separated by an air gap transmit far less sound than a single layer of equivalent total mass. The air gap decouples the panels so vibrations cannot conduct directly between them. This is why the concrete walls with RSIC clips and air gap achieve STC 65.

Green Glue (Viscoelastic Damping): Applied between two layers of gypsum, Green Glue converts sound energy into heat via shear deformation of its polymer matrix. It is most effective between 100--5000 Hz, providing an additional 5--9 STC points versus gypsum alone. The Buffer Spine gains STC 55 partly through this mechanism.

RSIC Clips (Resilient Sound Isolation): These rubber-isolated mounting clips break the structural (rigid) connection between the wall and the furring channel. By eliminating the direct conduction path, flanking transmission drops significantly. RSIC-1 clips on the north wall and RSIC-V clips on the diagonal provide the final isolation push to achieve STC 65.

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