Sound Attenuation Ducts Walls
Reference data and engineering information about sound attenuation ducts walls for acoustics applications.
soundattenuationductswalls
Overview
Engineering reference data for Sound Attenuation Ducts Walls in acoustics.
Key Formulas
Speed of Sound
Speed of sound in an ideal gas.
Sound Level
Decibel level.
Wavelength
Wavelength = speed / frequency.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Speed of sound | m/s | |
| Sound level | dB | |
| Wavelength | m | |
| Frequency | Hz |
Sound Transmission Table
The following table provides typical sound transmission loss (TL) values through rectangular duct walls based on sheet metal thickness and frequency.
4 rows
Duct Sheet Thickness(mm) | 125(dB) | 250(dB) | 500(dB) | 1000(dB) |
|---|---|---|---|---|
| 1.25 | 17 | 22 | 25 | 29 |
| 1 | 15 | 20 | 23 | 27 |
| 0.75 | 14 | 19 | 22 | 26 |
| 0.65 | 12 | 17 | 20 | 24 |
Source: engineeringtoolbox.com
Duct Geometry Note
The acoustic performance of round and oval ducts is superior to that of rectangular ducts. Their curved surfaces allow less breakout noise, and they are particularly effective at containing low-frequency sound.