Rearemitted

Rearemitted is a term used in the field of acoustics to describe the phenomenon that occurs when sound waves emitted from a transducer or an acoustic source are reflected, scattered, or otherwise redirected and then re‑emitted from the rear surface of the device or surrounding structure. The concept originated in the early 2000s when engineering teams working on high‑fidelity loudspeaker designs observed that a significant portion of the acoustic energy that passed through a speaker diaphragm was not absorbed but rather scattered by internal structures such as the frame or enclosure. These waves then propagated backward, emerging from the rear of the loudspeaker and contributing to the overall sound field.

Rearemitted energy is typically measured using two‑microphone techniques; a microphone placed in front of the speaker captures the forward emission, while a second microphone behind the speaker captures the rearemitted component. Engineers compare these recordings to quantify the rear‑side energy and to form strategies for minimising it through enclosure design, damping materials, or rear‑side porting. Because rearemitted sound can interfere with direct sound and affect soundstage imaging, reducing rear‑side emission is considered an important goal in premium audio equipment. The term has also appeared in research papers on wave‑guide acoustic metamaterials and ultrasonic imaging, where rear reflection or reemission from a substrate can influence system performance.