Dolby Atmos at home: speakers, ceiling and calibration

Dolby Atmos is on almost every soundbar box and every receiver. Whether it really works at home is decided by the ceiling, the placement and the calibration.

Which speaker configuration does Atmos need?

Atmos adds height channels to the surround layer; the third digit counts them. 5.1.2 means five speakers at ear height, one subwoofer, two height speakers; 7.1.4 seven, one and four.

Ceiling speakers or upfiring modules?

Atmos sounds cleanest with speakers in or on the ceiling. Dolby recommends the front height speakers at around 45 degrees of elevation in front of the listening position, the rear ones mirrored behind; ceiling heights between 2.3 and about 4 metres work well. With the concrete ceilings of Swiss new builds we work with surface-mounted speakers or a suspended section above the seating row; in timber and plasterboard ceilings in-ceiling speakers are possible with little effort.

Dolby Atmos enabled speakers (upfiring modules) radiate from the front speakers diagonally upwards and use the reflection off the ceiling. That only works with a flat, hard ceiling between about 2.3 and 3.5 metres – sloping roofs and acoustic ceilings destroy the effect, and the sound stays more diffuse. We use them when cables in the ceiling are out of the question.

Soundbars with Atmos

A soundbar with upfiring drivers creates a first height layer via the ceiling; good models with separate rear speakers and subwoofer achieve a credible 5.1.2 or 7.1.4. Soundbars without height drivers compute Atmos purely virtually – that widens the soundstage, real height rarely emerges.

Receiver and calibration

The AV receiver needs as many amplifier channels as speakers are connected: 7 for 5.1.2, 9 for 5.1.4, 11 for 7.1.4.

Calibration decides the rest: Audyssey MultEQ XT32 (Denon, Marantz), Dirac Live (Onkyo, Arcam, NAD, StormAudio) and YPAO (Yamaha) measure every speaker with a microphone at several seating positions, set distances and levels and correct the frequency response to the room. Practical rules: microphone at ear height on a stand, quiet room, six to eight positions around the main seat, then check the crossover frequency – 80 Hz suits most speakers.

Sources and formats

Conclusion

Atmos stands or falls with the height speakers and their calibration. Anyone who can use the ceiling should do so; anyone who cannot is better off with a soundbar with real height drivers than with upfiring modules under a slope. We plan the positions from your floor plan and calibrate the system after installation – in the consultation we compare 5.1.4 and soundbar at your seat.