SBIR (Speaker Boundary Interference Response) is a common issue that can occur when speakers are placed near walls or other boundaries in a room. This phenomenon happens when sound waves from a speaker reflect off of the boundary and interact with the direct sound from the speaker, resulting in uneven frequency response and phase cancellation.
The primary cause of SBIR is the time delay between the direct sound from the speaker and the reflected sound from the boundary. This delay can cause the reflected sound to arrive at the listener out of phase with the direct sound, resulting in reduced overall volume and uneven frequency response.
To avoid SBIR, it is recommended to keep speakers away from walls and boundaries by at least a quarter of the wavelength of the lowest frequency being produced. This can be achieved by placing speakers on stands, or by using techniques such as bass traps to reduce the effects of boundary reflections.
If you are unable to move your speakers away from boundaries, you can use digital signal processing tools such as EQ and delay to adjust the frequency response and phase alignment of the speakers. This can help to mitigate the effects of SBIR and improve the overall sound quality in your room.
Please also see: Speaker Placement & Setup