Sound Attenuation End Reflection

Overview

Engineering reference data for Sound Attenuation End Reflection in acoustics.

Key Formulas

Speed of Sound

$c = \sqrt{\gamma R T}$

Speed of sound in an ideal gas.

Sound Level

$L = 10 \log_{10}(I/I_0)$

Decibel level.

Wavelength

$\lambda = c / f$

Wavelength = speed / frequency.

Variables

Symbol	Description	Unit
$c$	Speed of sound	m/s
$L$	Sound level	dB
$\lambda$	Wavelength	m
$f$	Frequency	Hz

Sound Attenuation Data

The table below provides typical sound attenuation values in decibels (dB) caused by end reflection from a duct to a terminal.

Key Properties & Notes

• Frequency Dependency: Lower frequency sound waves are reflected more effectively than higher frequency waves.
• Terminal Shape: Sharper, right-angled terminal ends cause more reflection than rounded ends.
• Funnel Ends: Reflection losses in flared, trumpet-like ends are negligible.

Interactive Charts

References

• Original Source