What is STC? Understanding Sound Transmission Class - The Sound Project Ep. 123

In this episode, Gavin kicks off a new series on acoustical terminology by breaking down STC (Sound Transmission Class). Learn what STC really means, how it’s used in the industry, and why it doesn’t always tell the full story. Whether you're an architect, contractor, or just acoustics-curious, this episode will help you better understand how sound blocking works (and where STC falls short).

Video By: More Than Media - www.morethan.media
Instagram:   / morethan.media  
TikTok:   / morethan.media  
YouTube:    / @morethanmedia_  

The S.O.U.N.D. Project Podcast:
Apple Podcasts: https://podcasts.apple.com/us/podcast...
Spotify: https://open.spotify.com/show/6dkk1s6...
Google: https://podcasts.google.com/feed/aHR0...
Full episodes playlist:    • The SOUND Project  

Keep up with us on our Socials:

YouTube:    / @haverstickdesigns  
Instagram:   / haverstickdesigns  
Facebook:   / haverstickdesigns  
TikTok:   / haverstickdesigns  
LinkedIn:   / haverstick-designs  
Linktree: https://linktr.ee/haverstickdesigns
Website: https://www.haverstickdesigns.com/

00:00 – Intro: Welcome to The Sound Project
00:08 – Launching the New Acoustics Series
00:13 – What Is Sound Transmission Class (STC)?
00:25 – How STC Measures Sound Blocking
00:42 – Why STC Can Be Misleading
01:19 – STC Rating Levels Explained (25 to 65+)
03:16 – How STC Is Measured (Lab vs. Field)
05:54 – Interpreting STC Charts & Deficiencies
06:22 – Real-World Examples: Doors, Drywall, Vinyl, Concrete
08:14 – STC’s Limitations: Low Frequencies & Impact Noise
10:13 – Flanking Paths and Field Testing (ASTM E336)
11:17 – Comparing Wall Types: Concrete vs. Steel Stud
12:45 – Using the Sound Isolation Simulator Tool
15:14 – Summary: When & How to Use STC Effectively
16:18 – Final Thoughts & Viewer Q&A Invitation