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Articles tagged “octave band”

3 articles covering octave band in acoustic engineering and building design.

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GUIDES19 min read

The 125Hz Problem Nobody Treats — Why Your Meeting Room Still Sounds Like a Cave

Meeting rooms pass RT60 tests at 500Hz and still sound terrible. The culprit is 125Hz bass reverberation — standard acoustic foam panels have α ≈ 0.05 at 125Hz and do almost nothing. Here is the calculation that reveals the problem and the bass trap specification that solves it.

March 14, 2026
bass trap125Hz
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TUTORIALS20 min read

Understanding Octave Band Analysis: Why Single-Number Ratings Hide the Truth About Your Room

A single RT60 value or NRC rating averages across frequencies and hides critical problems. Octave band analysis breaks sound into 6 frequency ranges — revealing that your room might pass at 500Hz and catastrophically fail at 125Hz. Here is how octave bands work and why every acoustic assessment should use them.

March 14, 2026
octave bandfrequency analysis
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GUIDES17 min readFeatured

NRC 0.75 Does Not Mean 75% Absorption — Here Is What It Actually Means

NRC is an arithmetic average of four octave bands. A panel rated NRC 0.75 can have α = 0.40 at 250Hz — and that bass deficiency will make your meeting room fail its WELL F74 assessment at the exact frequency where speech intelligibility lives.

March 13, 2026
NRCabsorption coefficient
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