Which wall, door or window blocks what?

Filter real assemblies by STC and, separately, by how they handle bass. STC stops at 125 Hz, so the low-frequency column tells you what the rating cannot.

What are you trying to block? Can you do construction?

Minimum STC: 20

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STC	Assembly	Type	Note

Ratings are typical published laboratory values. Real rooms usually test 5 to 10 points lower because sound leaks around the assembly.