Sound Door / Acoustical Door / STC Assembly
The STC (Sound Transmission Class) is a way of measuring how much sound is lost when it travels through
a barrier, such as a sound door assembly, also called an acoustical door assembly.
The STC rating of sound door assemblies rise as less and less sound penetrates through it.
That STC rating is roughly the difference in decibel reduction as the sounds travels from the source, through
the barrier, and to the other side of the sound door assembly (acoustical door assembly). So, if 80 decibels
of sound went through sound doors and only 50 decibels makes it to the other side, the sound doors are
said to have an STC of 30. The graph below gives you an idea of what kind of sound reduction is allowed by
each STC door rating.
We even offer a STC 51 sound door assembly that complies with the Americans with Disabilities Act (ADA)
and the American Society for Testing and Materials (ASTM).

In government or business settings, overheard information can be a threat to anything from national
security to important business initiatives. At Mesker, we advise that you consider the potential cost of
privacy and the transmission of sensitive information, by looking closely at the STC sound rating of the
sound doors you order. Quality acoustical doors from Mesker are a smart investment.

Sound door and frame reduction is in many commercial and municipal
buildings a matter of security.