Whether you’re listening to music, watching a film or television programme, or playing a video game, a good audio setup is important. Where high quality sound is the goal, an unfortunate amount of times, the acoustics of the room is ignored. This short series of articles aims to help you figure out what makes your room sound good (or bad!), and how to make it better.
One of the problems is that the word ‘acoustics’ is often used as jargon and most people don’t want to hear about it. Even the highest quality, super high-end, speaker system will sound weak in the wrong room. Opting for a top-tier set of speakers does not guarantee you’ll get the amazing sound you’re looking for.
When you look at a speaker, it’s quite clear that a lot of care and attention has gone into designing the shape, position of the drivers, and the space inside the box. All of this is to make sure that the air the speaker moves, moves in a way that is acoustically pleasing. The room your speakers are in is an enclosed space, much like the speaker itself. The acoustic condition of the room makes just as much of an impact on the sound as the shape and size of the speaker.
Reflections and the Critical Distance
Sound is made of waves of pressure through the air. These waves bounce off of surfaces, much like a ripple in a bathtub full of water bounces off the walls. This bounce effect is called a reflection. Depending on the material and shape of the surface, a reflected sound will have different characteristics. Each reflection a sound makes can affect phase, frequency response, definition, aggressive highs, blurred stereo image, and resonant or boxy-sounding low frequencies.
If your ear is pressed up against the speaker cone, you’ll be hearing practically 100% direct sound—meaning sound directly from the speaker. If you’re standing 100 metres away from it, practically 100% of what you hear will be reflected sound (or reverberant sound). There’s a sweet spot where you’ll hear roughly 50% of both direct and reflected sound. This is called the critical distance. Can you guess where this would be? 50 metres? 25 metres? Well… no.
In a normal ‘medium sized’ room with normal furnishings, the critical distance is just two metres away from the speakers. Bear in mind, that also means the speakers are pointing directly at your head, too.
I think it’s fairly safe to say that most people will sit more than two meters away from their speakers when listening to music. This means that most of the sound reaching your ears has bounced off of at least one surface on its way—each bounce changing the quality. An easy way to check how your room is affecting the sound is to play a song, nice and loud, that you know very well. You should be very familiar with the song, so you know exactly how it should sound. Once it’s playing, walk around the room. Turn to face different walls, stand in the corners, move all the way to the back of the room, etc. You should notice some pretty huge differences in how things sound.
In the next article in this series, we’ll discuss the ideal listening room, and the measures that can be taken to make your listening room better!