Acoustic Enclosure Transmission Loss & STC Calculator
Determine mass-law panel transmission loss ($TL$), internal sound buildup ($L_{rev}$), and net noise reduction for machinery acoustic enclosures.
Enclosure Wall & Lining Construction
16-ga steel: ~12 kg/m², 1/4" plate: ~50 kg/m²
2" fiberglass: ~0.70 - 0.85
Gaps around pipes, doors, louvers
Acoustic Transmission Loss & Net Attenuation
Panel Transmission Loss (TL):
—
Net Enclosure Insertion Loss (IL):
—
Exterior Noise Level (L_p2):
—
Internal Reverberant Buildup:
—
Estimated STC Rating:
—
Leakage Penalty:
—
Acoustic Enclosure Insertion Loss Principles
Enclosing a noisy compressor or turbine requires two acoustic elements: high-mass outer walls to reflect sound energy (Transmission Loss), and an interior absorbent fiberglass lining to dissipate reverberant energy trapped inside.
Acoustic Flanking & Gap Leakage
The composite transmission loss of an enclosure is extremely sensitive to gaps and unsealed penetrations. Even an unsealed gap area of only $0.5\%$ caps the maximum theoretical noise reduction at less than $23\text{ dB}$, regardless of whether the steel panels are $5\text{ mm}$ or $50\text{ mm}$ thick.