There is much to gain by using Front Presence Speakers in the ceiling for Height effects. Using in ceiling Surround Back Speakers would not be advised as they should be placed at ear level along with the Front, Center, and Surround Speakers. Again, when using Front Presence Speakers, the Surround Back Speakers, if equipped, would not receive a signal when decoding Dolby Atmos and DTS:X or when using the Dolby Surround and DTS Neural:X up mixers.