Improving your sound system is – for those who read Alpha-Audio regularly – an ongoing quest in which several interests compete for precedence. Time, Money, Space and Housemates are the elements that tear the music lover into quarters. If we look into our audio hearts then speakers of 2 x 2 meters would be no problem at all, as long as it sounds good. But then again, how do we explain that at home and what should it cost? The audio equipment currently on sale excels in soundstage and detail. This ensures that things like placement and acoustic properties of the listening room really matter.
Location, location, location
No matter how good your speakers are, essential is how you place them. For starters, decouple them from the surface to eliminate resonance. Good speaker stands for monitor speakers or for floorstanders can be bought at reasonable prices, for example from Isoacoustics. We use a couple of Isoacoustics models ourselves. And they work very well. Not for free… but effective!
Then the position in your room/listening room. Speakers that are too close to the wall often produce too much bass. Especially with bass-reflex ports that are pointed backwards or sideways this problem occurs. Therefore, place the speakers – in most cases – as far from the wall as possible (preferably 70 cm or more). Then see what that does for the bass.
Give the speakers some toe-in and listen what you find comfortable. In general; the more toe-in, the sharper the imaging. And the less interference you have with the sidewalls. For ribbon or AMT tweeters, this rule is a little less true. Note that the listening height is the area between the tweeter and the driver All this should lead to a better soundstage and a more balanced sound image.
A golden rule, is the ‘rule of thirds’. In this, you divide the room into three equal sections. The speakers come on 1/3, you sit on 2/3. This placement rule says something about the ideal listening triangle, but also ensures as little disturbance as possible from standing waves. If you find the rule of thirds impractical in your room, replace the number three with five.
Diffusion and absorption
Good room acoustics are not only good for audio playback, they make staying in the room pleasant. Think about the times you enter a movie theater or a theater auditorium; a pleasant calm comes over us; the sound of conversations in the audience is muffled. Compare that to a parking garage where bare concrete and glass dominate, or a large cafe with industrial decor. Shrill, loud and penetrating sounds do not make it pleasant to stay there for a long time.
Then the question: how are the acoustics in your living room/listening room? Clap your hands a few times in different places and listen. Is there reverberation, does the sound resonate, and are they mostly high or lower frequencies? What is it like when there are more people in the room talking interchangeably? Is it easy to understand or does everything blend together?
A nice and very effective way to remove reverberation is to hang (heavy) curtains or put down some thicker rugs. Large glass surfaces and hard floors or ceilings are often the cause of unwanted reflections. On the other hand, a room where too much sound is absorbed is also complicated, because you then need heavy amplifiers to bring the energy into the room. Think of a movie theater where amplifiers with thousands of Watts of power are in place. Maximum control of the sound and an absorbed room means that all the energy must come from the speakers.
The acoustic properties of a good listening room, if done right, help the speaker distribute the energy across the room.