Acoustic Design Learning Center
From first principles to advanced techniques — learn room acoustics, reverberation time calculation, and compliance standards.
The Acoustic Design Process: From Brief to Handover in 8 Steps
Acoustic design follows a structured 8-step process: establish criteria, model the room, calculate the baseline, identify deficiencies, specify treatment, verify compliance, document, and measure post-construction. Here is each step explained with the specific deliverables and ISO references.
A Practical Guide to Acoustic Materials: Foam, Mineral Wool, Wood, and Everything In Between
Acoustic materials fall into three categories: absorbers, reflectors, and diffusers. Each type works differently at different frequencies. Here is a practical guide to selecting the right material for your room — with NRC values, octave-band data, cost ranges, and fire ratings for every major product type.
How to Measure Room Acoustics: Equipment, Methods, and What the Numbers Mean
Measuring room acoustics requires a sound source, a microphone, and analysis software — but the method you choose determines whether your results are valid. Here is a practical guide to acoustic measurement: from balloon pops to dodecahedron speakers, from smartphone apps to ISO 3382-compliant equipment.
Noise Criteria Explained: NR, NC, and RC Curves — Which One Does Your Project Need?
NR (Noise Rating), NC (Noise Criteria), and RC (Room Criteria) all rate background noise levels in buildings — but they use different curves, different frequency ranges, and are required by different standards. Here is how each system works, when to use which, and the specific values your HVAC engineer needs to hit.
Room Acoustics Fundamentals: How Sound Behaves Inside a Room
Sound in a room does not simply travel from source to listener. It reflects off every surface, arrives at the listener hundreds of times with different delays, and creates a complex acoustic signature. Here are the fundamentals of room acoustics — from direct sound to late reflections to standing waves.
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.
Understanding Sound Insulation: STC, Rw, and Why Walls Don't Block All Frequencies Equally
STC (Sound Transmission Class) and Rw (Weighted Sound Reduction Index) both rate how well a wall blocks sound — but they use different standards, different frequency ranges, and can give different results for the same wall. Here is what each rating means, how they are measured, and which one applies to your project.
What Is NRC (Noise Reduction Coefficient) — The Number on Every Acoustic Panel Datasheet
NRC is a single number rating from 0.00 to 1.00 that describes how much sound a material absorbs. But NRC hides critical information about low-frequency performance. Here is what NRC means, how it is calculated, and why you need octave-band data for any serious acoustic design.
What Is RT60 — And Why It Determines Whether Your Room Sounds Good or Terrible
RT60 is the time it takes for sound to decay by 60dB after a source stops. Too long and speech blurs. Too short and rooms feel dead. Here is what RT60 means, why it matters for every room type, and the optimal targets that acoustic standards have established over 100 years of research.
What Is STI (Speech Transmission Index) — Can People Actually Understand Speech in Your Room?
STI measures how much a room degrades speech from source to listener, on a scale from 0 (unintelligible) to 1 (perfect). An STI below 0.50 means one in four words is lost. Here is how STI works, what scores you need, and why reverberation time alone is not enough.