Quiet Rock - Design

Design

QuietRock uses a damping technique called constrained-layer damping (CLD). This technology had been used for at least 20 years to reduce vibrations in mechanical objects from disk drive heads to bridges, but had not been widely applied to architectural acoustics prior to 2003. QuietRock panels use several constrained-layer systems to create a higher ability to damp vibrational (and therefore acoustic) energy. In essence, the panel does not "want" to vibrate due to stress and strain caused by the damping method. Acoustic energy ends up dissipating as small amounts of heat (which cannot be heard). Standard drywall and cement board panels are laminated together with QuietGlue.

Sound attenuation is measured using tests known as ASTM E90 and ASTM E413 to achieve a single sound-transmission-class (STC) rating. Note that the STC method has changed significantly over the years, and STCs from publications prior to 1995 may not be accurate to today's standards. QuietRock is one of a class of soundproof drywall products that, according to independent lab tests and field reports, may add 15 to 20 STC points in comparison to standard drywall. STC does not consider the most problematic frequencies below 125 Hz.

Unlike resilient channels (RC) and other methods, internally damped drywall cannot be shorted out by the builder or homeowner. Therefore, the use of "soundproof drywall" may be a more reliable method for sustained high STCs.

Two companies have published third-party tests of mass-loaded vinyl (MLV), an older method used by do-it-yourselfers for home studios. These tests show that MLV scores 43 to 45 STC points in 24-inch-on-center (24OC) single-stud walls, whereas internally damped drywall typically scores 50 to 55.

People can make their own CLD panels using various viscoelastic polymers available from several companies. These glues can be spread at 1/2 gallon to 1 gallon per layer to improve the STC values of standard drywall and are less expensive than engineered panels, even considering professional labor rates.

QuietRock panels are made from standard drywall or cement board and polymers. One model (530) uses thin metal to add a shear rating. Many are UL certified for fire rated assemblies. The company said in 2008 it had shipped more than 1 million panels.

Quiet Solution was awarded a patent in early 2007 and subsequently sued Supress Products, started by a former employee, for patent infringement The suit was later settled out of court.

There are other internally damped panels on the market as well, such as Supress Products, National Gypsum's SoundBreak introduced in 2008, and Temple-Inland's ComfortGuard.