Articles tagged “NC curve”
8 articles covering NC curve in acoustic engineering and building design.
Background Noise Curves: NR, NC and RC Compared
Compare NR, NC, and RC background noise rating methods with worked examples showing which curve to specify for HVAC noise control in offices, studios, and hospitals.
Dolby Atmos Cinema: The Acoustic Requirements Behind Immersive Audio
Dolby Atmos certification requires NC 30, RT60 0.2–0.3s, and 64+ speaker positions. Here's the full acoustic brief every cinema designer needs to understand.
HVAC Noise Control — The Ductwork Mistake Ruining Your NC 30 Spec | AcousPlan
HVAC duct velocity above 5 m/s generates noise proportional to V⁵. NC curve calculation chain with ASHRAE method. 5 noise sources, 1 worked example.
NC Curve Calculation from Octave-Band Measurements — Step-by-Step
Determine the NC rating from a set of octave-band background noise measurements. Step-by-step tangent curve method, controlling frequency identification, and RC Mark II comparison.
NC vs RC vs NCY — Which Noise Criterion? Most Engineers Pick Wrong | AcousPlan
NC misses rumble below 63 Hz. RC Mark II identifies spectral quality. NCY adds 5 dB penalty. Full comparison with decision matrix and worked example.
What Is Noise Criteria (NC)? — Background Noise Rating for Buildings
NC curves rate background noise across octave bands to reflect how human hearing perceives HVAC and mechanical noise. Learn what NC numbers mean, how they are measured, and what targets apply to your building type.
ASHRAE HVAC Noise Control: Handbook Chapter Summary for Acoustic Designers
ASHRAE HVAC Applications Chapter 49 is the authoritative guide for mechanical noise control in buildings. This summary covers RC/NC curve criteria, duct noise calculation, equipment selection, and silencer design for acoustic designers.
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.