The best placement is between 90° to 110° from each side of your listening position.
The best surround speakers are Dipoles. Their role is to offer a wide dispersion of sound in all directions, giving benefits such as a transparent and detailed sound and rear channel effects that are similar to a true cinema experience, created by the rows of side loudspeakers.
The best placement of Dipoles are between 90° to 110° to each side and about 70cm or higher above the listener's ears.
The greater the distance of the speakers from the walls the better their response
Place the main speakers slightly in front of the TV and not at the same line with it, so that he distance of the main speakers from the listening position is identical to that of the center speaker. Placing the speakers this way also reduces the reflections from the TV screen
The speakers must form an isosceles triangle with the listening position. The speakers are placed in font of us just like a live orchestra
The greater the distance between the main speakers, the wider is the stereo image that we get. However we must be careful not to place the speakers too far apart, or we will create an acoustic hole between them
The tweeter must be placed at the ear level when seated at the listening position an there should be no objects in the direct path of the sound to our ears
Slightly turning the speakers towards the listening position improves the sound focus but it reduces the dimensions of the sound image. This affects some speakers more than others. Trial is the best way to determine this...
All speakers must be broken in for some time. Use your speakers for at least for 100 hours in mid to low listening levels, before they can perform at their best.
Align its facade with the TV screen, to reduce diffraction. Diffraction is the secondary sound generated when sound meets a discontinuity
If the speaker is placed below the TV, tilt it upwards, towards the listeners. If it is placed above the TV, tilt it downward towards the listeners
Make sure that the central speaker is not placed above or below the tweeter level of the main speakers by more than 60-70 cm
The reflections from the Surround speakers are useful, in reverse of the reflections of the main speakers that are destructive to the sound quality
The tweeter must not aim at your ears
The sound must be directed towards a wall so that it reaches our ears after a reflection
It is preferable that they are placed at least 50 cm above the ear level of the seated audience
The successful placement and adjustment of a subwoofer is the result of many trials. A correctly placed and adjusted subwoofer generates sound that cannot be localized as coming from a separate speaker.
Place the subwoofer near the listening position. Play a jazz piece with acoustic bass and many succeeding notes "walking bass". Get down on your knees (beware of your neighbors...) and find the exact point of the room where the bass sounds the clearest. Now change position, place the subwoofer at this spot and sit at your listening position.
Avoid placement of the subwoofer equidistant from the two walls. If, for example, the width of the room is 8 m, do not place the subwoofer at the middle of this distance (4 m).
Do not place the subwoofer in the corner and at the same distance from the two corner walls.
Place the subwoofer as close to the listening position as possible. This way you will experience more of the direct sound of the subwoofer instead of the reflections of the room.
The use of two subwoofers, to the left and to the right of the listening position, is the ideal albeit more expensive solution.
The ideal location for the subwoofer may not be practical. Think of the decor of the room and make sure the subwoofers are not in the way.
Experiment with various locations based on the above suggestions. You will be rewarded with much better sound without additional cost.
You will enjoy uniform, fully extended low frequencies with minimal to none standing waves.
Extensive THX and AES (Audio Engineering Society) research has proven that the use of two and - even better - four subwoofers is the best solution for achieving a uniform bass performance for many seats around the listening area.
Each subwoofer creates its own modes, which overlap randomly with the modes of the other subwoofers in the room. Statistically, this results in a more uniform result, with the big dips and peaks in the low frequency response being mitigated considerably.
Overall, the use of at least two or even four subwoofers, leads to the following advantages:
For the ones craving the most realistic LFE experience, the extra cost is definitely worth the effort!