The Science of Sound PART III: Let’s Talk About STC

Aug
29
2017

LAB TESTING & STC

Currently, the most widely accepted standard for ranking the acoustical performance of accordion and operable partitions is STC or Sound Transmission Class. Virtually every manufacturer conducts laboratory tests for STC.

FINDING STC

Sound Transmission Class is a two-digit number describing the laboratory performance of a single building element in stopping the transmission of sound through it. It is found from individual STL figures of 16 frequencies between 125 and 4000 Hertz.  The STLs are found through the formula described earlier, completely defined by ASTM Standard E90.

The procedure for finding the STC is defined in ASTM E413. Refer to the graph while following the steps below.

  1. Plot the STLs on the graph.
  2. Plot the standard STC curve.
  3. Move this standard curve as high as possible so that:
    1. no frequency’s STL falls below the standard curve by more than 8 dB (Each dB below the curve is called a “deficiency”).
    2. total deficiencies do not exceed 32.
  1. Locate the level on the standard curve corresponding to the 500 Hz frequency. This is the STC.

How Good is an STC Rating? Find out next week! Until then, this may help you.

The Science of Sound Part VII: Beating Flanking Paths

The first step to beating flanking paths is to look at how all of the elements work together from floor to roof-the partition, the space between the ceiling and the roof, the floor, even HVAC ductwork can help or hinder flanking paths.

The Science of Sound Part VI: Flanking Paths

Shoddy construction, customary construction practices, or poor installation of the partition can all contribute to the leaks, known as flanking paths.

Hufcor Joins ‘Making Room’ Exhibit in D.C.

While Hufcor is well-known for movable wall systems within commercial market segments such as education, office, hospitality and convention centers, the solutions for this exhibit are to promote architectural thought expansion for future shifts in demographics and lifestyle changes.