The speakers are the most dominant component in a stereo or home cinema system, and attention to their location will improve sound performance, sometimes even create a very significant difference.
What Does Speaker Location Affect?
Locating the front pair of speakers is most important, they provide most of the effect and also when listening to stereo music when only both of them are working – their situation in the room significantly affects the size and depth of the soundstage, the location of the instruments and balance of frequencies. In fact, location and acoustics of the room are a type of calibration for the speakers.
Your audio system ideally creates soundstage in the room; the location of the speakers will affect the depth of the soundstage, its width and height. There's even an affect on the focus of the sound: correct location will make the images of the playing instruments clearer. A high quality system will radiate a “sonic hologram”, in which you can close your eyes and accurately listen to where each musical instrument is located on the stage, as well as the singers and feel like the band is in the room with us. Further characteristics that are affected by location are inter – frequency balance and precision of the bass, there are a few cases where moving the speakers made the sound more balanced and pleasant, without having one frequency predominate the others.
Stereo vs. Home Cinema
Stereo amplifiers include tone controllers (which enable control over treble and bass), some of them (mainly those designed for audiophiles) have only a volume dial, which means that the only calibration that can be made in the system is correct situation of the speakers as well as acoustic treatment of the room.
Modern home cinema amplifiers enable acoustic tuning and calibration, they include a microphone which identifies problematic frequencies and together with the amplifier's computer, location and acoustic problems can be overcome in theory. But despite of this, it's recommended to pay attention to location of the speakers because it'll always improve the sound.
Front Speakers: The Golden Triangle
The basic rule of location says that both of the speakers need to stand in an equal distance and identical angle from the user, as well as in an identical angle that creates an isosceles triangle with the listener's position.
The optimal listening point will be at the vertex of this triangle, it's called "the sweet spot" because in it you get the most impressive and accurate picture of sound.
It's important to create a minimal distance which will create depth and stage width. At a distance of three metres, we recommend a space of at least 1.5 metres between the speakers until about three metres.
It's hard to give an exact formula because it depends on the physical size of the speaker units and the distance from the listener. Keep in mind that too big of a distance between the two front speakers will damage the stereo picture and you'll feel an artificial separation between the speakers.
Tweaking the Tweeter
The more we rise towards the upper edge of the frequencies, the more the sound adjustment increases: therefore, if we turn the tweeter (the speaker in charge of high frequencies) to a different direction from the listening point, we'll immediately feel a reduction in sharpness of sound. The high frequencies are very important: they contribute to three dimensionality of the sound and creation of the instrument's and singer's location in the room.
Not only is the tweeter itself important, but also it's height: if you'll examine a few types of floor speakers, you'll find that most of them have a tweeter at the height of the listener's ear (as long as the listener is sitting on a sofa at an average height), which places the tweeter at a height of around 85cm above the floor. In case of a shelf speaker, it must be placed on a suitable shelf (60cm high) so that the tweeter will be place at the height of the listener's ear.
Location of the tweeter's angle: the speaker can be placed in such a way that its rear is in a straight angle opposed to the rear wall and the tweeter faces the wall in front of it straight ahead. In this case the high frequencies will be refined a little; the stage will become wider but less focused. If you incline the tweeter towards you, so that the speakers face you, you'll receive amplification of the high frequencies and a more focused stage.
Each manufacturer recommends a different angle for its speakers, it is recommended to try different angles at home until you find the position that suits you.
Satellite Speakers and the Subwoofer
Satellite Speakers: these kinds of speakers are generally designated for hanging on the wall, the higher we'll hang them the more we'll receive a less accurate and scattered sound, its suitable for background music and movies, but if you're interested in a more focused sound you should hang the speaker at ear level. On the other hand, the lower the frequency, the more the directionality lessens. For this reason a subwoofer (in charge of the lowest frequencies) can be installed in different corners of the room: our ear won't notice the direction from which the bass sound is coming from.
Take a look at the speaker's cabinet. If you'll notice a big hole in its back, you should place the speaker at least half a metre from the wall or even more. Sound waves on a relatively low frequency come out of this opening, when they hit a close back wall they are amplified, which causes the bass frequencies to sound stronger in comparison to the others and this leads to a bloated bass, echoes in the room and damage in preciseness and balance of the overall sound. The further you place the speaker from a rear wall the more it'll receive "breathing space" and demonstrate the original sound it's capable of.
On the other hand if you have a small speaker, closeness to the wall will rather add it the power it lacks in the first place. The above rule also applies in the case of a side wall: you shouldn't place the speakers to close to side walls, in case of placing them in the corner the bass could be amplified up to three times its original capability! Speakers that arrive with a front opening are less sensitive to distance from walls, but in their case also never closen them to much to the wall.
Speakers Filled with Sand or Lead Shot
Part of the floor speakers include the possibility to fill them with sand or lead in their lower part, this makes the speaker case much heavier, helps soften vibrations or echoes of the case and helps to maintain preciseness of sound and a tightened bass. It certainly can help in cases where there's a bass echo in the room, but keep in mind that sometimes adding too much weight could make the sound lifeless.
In the case of a shelf speaker, the speaker's stand should be as heavy as possible, so that it doesn't buzz while playing the music (and turn into a musical instrument itself), furthermore, it acts as isolation between the speaker and the floor and contributes to a more accurate bass.
Spikes
The bottom of the speaker should stand on spikes: they look like thick needles or screws with a sharpened head. The spikes help isolate the speaker from the floor and mainly helps make the bass accurate and pleasant. In the case of a shelf speaker, it's recommended for the stand to stand on spikes and for the speaker itself to be isolated from the stand: isolating materials such as Blutack, which acts as an isolator but one that does stick and is very easy to remove, can be used.
By paying attention to these rules, we could achieve a result that expresses the speaker's capabilities in the room, sometimes, correct positioning could make all the difference in the quality of sound and turn a mediocre system to a musical and enjoyable one.
Center Speaker
This speaker generally handles the dialogue in movies. It should be placed in such a way that the height of its tweeter meets the height of the two front speakers' tweeter at its sides. In general, the center speaker should be a model of the same series of the rest of the speakers, so that the tone of sound is identical in all of them (in order to prevent a situation where sounds in different tones come out from the various speakers in the system).
Surround Speakers
In a home cinema system, the back speakers' role is to play effects and environmental sounds that are scattered in the room. If it's a system that is designated for listening to multi channel music, then the back speakers need to stand in a position where the tweeter is at the height of the listener's ear as well. If it's a system that is mainly designated for watching and listening to movies, the speakers can be hung at a higher level in the room and at an angle towards the listeners, so that wide field of sound is created throughout the space.
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