A 9.1.2 system uses 2 ceiling speakers in additional to a basic 9.1 system. This is only recommended for a larger listening room. For the requirement of 9.1.2 ceiling speakers, they are not easy to fit for apartment but better for house.
For the 9.1.2 system, it consists of:
|1||Surround Sound Processor / AMP||–|
|2||Center Speaker||1 set|
|3||Left / Right Speaker||1 for each side (L/R)|
|4||Left / Right Front Wide Speaker||1 for each side (L/R)|
|5||Left / Right Surround Speaker||1 for each side (L/R)|
|6||Left / Right Back Speaker||1 for each side (L/R)|
|7||Left / Right Ceiling Speaker||1 for each side (L/R)|
NOTES: for items 2-6, they are totally 9 normal speakers as 9 with the subwoofer as the “.1” and final “.2” refers to 2 additional speakers in-ceiling.
Let’s take a look on the floor-plan of the 9.1.2 theater.
The installation suggestion is based on the information available from the Dolby Lab. With our experience, it should be fine-tuned for every listening room. The key is the positioning as the angle of the speaker position and the physical height of the speakers.
To take an example, a room with wooden wall should be sounded very well. Further adjustment will be necessary for a brick wall. In order to build the best-fit system, you need to set your height and position of each speaker with the help of the AV system. Then, you have to compare the effects when sitting down at your seat by playing the same track until the most comfortable one. Moreover, the introduction of a pair of front-wide speakers may lead to overlapping of sound if the listening space being too small.
With the additional speakers are installed under the ceiling, the ceiling height for the listening room should be considered. It is better to have 7.5 to 12 feet suggested by Dolby lab. In real practice, it is suggested to have 10 feet or above.
Also, the 3-D plan is being shown below: