Studio Noise Criteria (NC & NR Curves): HVAC Silencing & Ambient Noise Floors

The dynamic range of any recording studio is fundamentally limited by its ambient acoustic noise floor. In professional architectural acoustics, ambient noise is measured against standardized Noise Criteria (NC) curves.

NC Curve Standards

• NC-15 to NC-20: World-class commercial recording studios, foley stages, and orchestral halls. Virtual silence.
• NC-25 to NC-30: Professional project studio control rooms and broadcast vocal booths.
• NC-35 to NC-40: Standard domestic residential rooms and quiet offices.

Silencing Studio HVAC Airflow

High air velocity through ducts generates acoustic turbulence noise. To achieve NC-20, studio HVAC systems employ oversized ducting to reduce air velocity below 300 feet per minute (FPM), paired with acoustic silencer baffle boxes lined with duct liner to eliminate fan motor whine.