Where we listen to our music has a great effect on the quality of the sound we hear.  However as we refine our audio systems we tend to forget our listening room.  Acoustics is a complex subject and I’m not planning to make an acoustician of you.  However I do hope in this post and others to help you understand some of the issues and guide how you might want to set up your listening room.

In considering sound in rooms we need to consider two aspects:

The time domain refers to when things happen.  Time domain considerations affect the soundstage, imaging, transients and dynamics.

The frequency domain deals with the frequency content of the sound.  Frequency domain considerations affect the tonal balance of the sound.

Different approaches are needed to address issues in each domain.  However both are important if we are to have good sound in our rooms.

Loudspeakers are designed with a wide range radiating patterns, ranging from highly directional to omni-directional.  Nevertheless the sound from your speakers travels throughout your room.  Therefore, in addition to the sound we hear directly from the speakers, we also hear sound reflected off the walls, floor, ceiling and all the objects in the room.  The strength, timing, location and frequency content of these reflections has a major impact on the quality of sound that you hear in the room.

When the sound from your loudspeakers reaches a room boundary or a room furnishing one or more of four things happens to it:

• It is reflected back into the room.
• It is absorbed by the obstacle.
• It passes through the obstacle.  This is called transmission.
• It bends around the obstacle.  This is called diffraction.

We will be chiefly interested in reflection and absorption, though you may also be concerned about transmission … to preserve good relations with the others at home and with your neighbours.  This is especially true for those living in apartments and townhouses.

The ideal listening room will be reflective enough to sound lively and natural, and will have sufficient absorption so that sound does not bounce around the room indefinitely, producing sonic confusion.  In seeking to strike this balance we also need to consider where our reflective and absorptive surfaces are, relative to the speakers and the listening positions.  In most cases we’ll also need to consider the other uses of the room and the needs and wishes of the others at home, to preserve domestic harmony.

Each system, room and situation is unique.  However with an understanding of the principles and some judgement and experimentation most rooms can be set up to provide good sound.

© Wayne Butcher