Sound Attenuators are used to reduce noise in HVAC systems. Design of Sound Attenuator is key in deciding basic size, splitter details etc. RIGID Industries use software for selection of Sound Attenuators and deciding the fabrication details. RIGID brand Sound Attenuators are available in three different sections. SA R for rectangular cross section (Fig 6.1) SA C for circular cross section (Fig 6.2) SA B for rectangular bend section (Fig 6.3).