Screen speaker placement recommendationsEach immersive audio format has a recommended range for the horizontal angle of the on-screen speakers, ranging from 44° to 60° between the left and right speakers and the RSP. This range is very close to the SMPTE recommended viewing angle for cinema projection (43°), the maximum viewing angle recommended for UHD 4K digital** (61°), and the optimal angle for 2-channel** reproduction (60°). Most importantly, the angle between the front left (FL) and front right (FR) speakers should match the viewing angle of the screen for sound-to-image consistency. The immersive sound format enables more accurate sound localization and subtle mixing, which means consistency between sound and image is more critical than ever. Sound-to-image consistency is ITU-R BS1909 Recommended Requirements. For guidance on how to properly adjust the screen size for sound-to-image consistency, refer to the CTA CEDIA-CEB23-B Home Theater** Design Recommendations. The front left (FL) and front right (FR) speakers should be placed as close to the edge of the screen as possible. If the entire audio-visual entertainment space is predominantly front-facing projection** movies, the front left (FL) and front right (FR) speakers should be placed behind the sound screen. In this case, the angle from front left to front right should be slightly narrower than the ** angle. At this point, it is also possible to place the speakers away from the sides of the screen, although this is less common and will result in a horizontal audio angle that is slightly wider than the ** angle. In practice, decisions can be made based on specific conditions, such as floor-standing speakers, reduced space behind the screen, or situations where the screen structure or occlusion system may block the speakers. A slight mismatch between sound and visual angle is not a problem, because the "ventriloquist effect", where the human senses associate sound with possible rather than actual**, will help the listener's brain associate the sound with the picture on the screen. If the system is primarily used for ** reproduction, it is recommended to set the angle between the FL and FR speakers and the RSP position to 60°. If the speakers are not behind the screen, it will alleviate the problem of attenuation of high-frequency sound caused by the sound transmission curtain. However, please note that placing FL and FR speakers close to the side wall increases the need for proper passive acoustic treatment. 
Number of screen speakers: 3 or 5Some immersive sound formats can use the space between the front-center (FC) and front-left and right (FL FR) speakers to add additional "center" speakers, called front-center-left (FCL) and front-center-right (FCR), respectively. It is important to note that these two new speaker positions can only be used if the surround sound processing is able to output the corresponding channel information independently. 
The number of screen speakers depends on the width of the horizontal viewing angle from the RSP position:If the horizontal viewing angle is less than or equal to 40° (20° from the center, indicating a narrow screen), then 3 screen speakers are sufficient, and the number of other speakers in the system is not affected. If the viewing angle is greater than or equal to 70° (35°, widescreen), it is recommended to use 5 speakers, while the number of other speakers in the system is not affected. It is recommended to place the additional FCL FCR speakers in a half-width or half-distance position between the front-center and FL FR speakers. The evenly distributed angle of the speakers across the screen ensures smooth, even movement of the sound source across the image. If the viewing angle is between 40° and 70° (in most cases), the following guidelines may apply: o If the number of surround speakers is less than or equal to 8, 3 screen speakers are recommended. o If the number of surround speakers is greater than or equal to 10, 5 screen speakers are recommended. 
When the horizontal viewing angle is less than or equal to 40° (left), 3 screen speakers are used, and when the horizontal angle of view is greater than or equal to 70° (right), 5 screen speakers are usedVertical alignment of screen speakersAs the resolution of image displays continues to increase, there is a trend towards the use of screens with a relatively larger relative area with a vertical viewing angle of about 18° to 34°. For recommendations on screen size and placement, see CTA CEDIA-CEB23-B. To maintain sound-to-image consistency, it is recommended to keep the acoustic center of the screen speakers within the middle third of the screen height. This is mainly to improve the subjective auditory comfort of the listener, enhance the effect in terms of vertical height, and at the same time maintain the good vertical consistency of the audio and image of the ** channel. 
The recommended range of vertical viewing angles for screen speakersThe vertical position of the center speakerWhen the front center channel speaker cannot be placed on the same level as the front left front right speaker, it is recommended to place it as close to the top or bottom of the screen as possible. The choice of top or bottom is influenced by the following factors:1The distance between the center channel speaker and the wall of the room. It is recommended that the center speaker be placed away from walls and furniture to avoid strong early reflections. 2.Keep the listener's voice path open (unobstructed). 3.The size and position of the screen. 4.Dispersion and coverage of screen speakers. 
Performance metrics of screen speakers, including sound pressure level differences between screen speakers, and frequency response differences between screen speakers between seats
Surround speaker placement recommendationsThe various immersive sound formats have similar recommendations for the layout of the surround speakers at the listener level, i.e. the ground floor, with evenly spaced surround speakers on the sides and behind the listening area. These recommendations generally apply to a single seat, but need to be adjusted for multiple seats in the home theater space. As the listener moves away from the RSP position, the surround image will change, and the distance between the seats in the listening area and the numerous surround speakers will undoubtedly be different. However, by adjusting the number and placement of surround speakers according to the listening area and room, the best surround performance can be achieved within the listening area to ensure that all listeners are able to achieve minimal panning. Surround speaker placement area is recommendedOne of the fundamental goals of immersive sound is to ensure that all listeners have the same great sound experience. In other words, when an image appears on one side, every listener should perceive the change from that side. Similarly, when an image appears at the back of the room, every listener should perceive that it is coming from behind. Since the introduction of 71 Since the advent of multi-channel surround sound technology, surround speakers have traditionally been divided into two subgroups: side surround speakers and rear surround speakers. In the object-based immersive sound format, this distinction between side and rear surround effects is still valid in listening areas with multiple seats, as the sound object position has corresponding coordinate positioning. So, in a multi-seat home theater, when all surround speakers are well tuned, you can be sure that all seats sound good. Surround speakers should be located on each side of the space, avoiding direct placement in the area behind the listener's area to ensure the correct left-right orientation for all listeners. In some cases, the left and right side placement areas can be extended forward to 50 cm of the front seats, such as placing ring-left-1-ring-right-1 speakers, or to mitigate the possible acoustic panning gap between the front-left-front-right and ring-left1-ringright1 in a long and narrow space. If you build a 5 without rear surround speakers1 system, usually using a larger angle to place the ring left and the ring right further behind. Depending on the size and shape of the space, this may extend to the back wall, but will not be located directly behind the listener area. The rear surround speakers should all be located behind the listener area. This rule ensures that no listener can perceive the presence of a rear speaker from their front. 
Recommendations for the side surround (left) and rear surround (right) speaker placement areas
Adjust the number of speakers in the listening areaThe recommendations for the number of surround speakers are as follows:1.The size of the listening area. In general, larger spaces, larger walls, logically require more speakers. 2.The distance from the listening area to the wall of the room. When a listener is close to a wall, they may be too close to one speaker and farther away from the other speakers relative to the RSP position. The use of more surround speakers will reduce the dominance of a single proximity speaker, improving the sense of space and immersion for all listeners by reducing the difference between speaker distance and angle. 3.Number of seat rows. If there are multiple rows of seats in the room, but there is only one speaker on each side of the wall (e.g. 71 system), the sense of positioning will change accordingly in each row. For example, if the side speakers are aligned with the middle row, the listener sitting there will hear the sound coming from next to them, while the front row will hear the sound coming slightly from the rear and the back row will hear the sound coming slightly from the front. The entire sound experience is inconsistent within the listener's area. This becomes more noticeable the closer the seats are to the speakers. Therefore, increasing the number of surround speakers can improve the consistency of the listener area and achieve a higher panto-spatial resolution. 
Increasing the number of side surrounds (right) will result in a higher spatial resolution of the pantogram between the seats.
Maximize the utilization of the loudspeaker through processing
Depending on the size of the home theater space, the number of seats, and the number of seats in rows, we can achieve a number of speakers that exceed the standard 4 surround positions. A higher number of speakers can improve the spatial resolution of the pan of the object-based immersive sound effect format, but not with 51 or 71 When a channel-based program source, you may only see a limited number of speakers participating, and not all speakers emitting sound. In practice, we can use the upmixing feature in the surround sound processor to extend channel-based content to more speakers. Upmixing is not limited to surround sound, and depending on the capabilities of the surround sound processor, it can be used in all speaker positions. In addition, if there are multiple rows of seats in the room, the Surround Speakers (SL SR) can be placed on both sides of the wall in an "array" to maintain image consistency between the rows of seats. Speaker arrays are achieved by feeding the same signal to multiple surround speakers, so that the entire speaker array has only a single channel of speaker sound reproduction. Physical arrays are created from shared processor outputs. All speakers in an array will reproduce the same content in the soundstage;They cannot be output separately for different channels of sound content. This technique is commonly used in commercial cinema rooms, where 2 or 4 surround channels are extended to multiple speakers distributed along the side and back walls for wider surround coverage. Physical arrays reduce positioning based on object content and are therefore not recommended. The software array is managed by a supporting processor, making its configuration content-dependent and providing individual controls (such as volume and delay) for each speaker at the same time. For example, a surround sound processor can output Dolby Atmos content to multiple side surround speakers via independent channels, but in Dolby Digital 71 Content changed to shared output to more efficiently build a side-by-side array. Whether it's an immersive sound system, or a combination of upmix and software arrays, the number of speakers should not exceed the number of individual speaker output channels on the processor (with the exception of subwoofers and LFEs).
Independent surround speaker channel configuration (left) vs. array side surround speakers (right).
Performance metrics for surround speakers, including the maximum permissible horizontal angle to each other and the difference in sound pressure levels between them
ENDS