Front-Height vs Top-Front Position

What the two terms mean

Marantz support gives the plainest definitions. A height speaker is an in-wall or on-wall speaker, typically placed above the front, surround or surround back channels. A top speaker is an in-ceiling or on-ceiling speaker that is used as top front, top middle or top rear depending on the application. A third type, the Dolby Atmos enabled speaker, is a module that sits on top of a front, surround or surround back speaker and uses reflection from the ceiling. So a front-height speaker is a wall-mounted height channel at the front of the room, and a top-front speaker is a ceiling-mounted height channel ahead of the main seats. Both are labeled with a ".2" or ".4" in layouts such as 5.1.2 and 7.1.4, and both must be installed in pairs.

Where each one goes: angles and the geometry

The Dolby Atmos Home Theater Installation Guidelines (April 2015) are the primary source. For the front height pair, Dolby says to mount the speakers on the front wall in line with an approximately 30 degree horizontal angle from the center-front reference, which places them directly above the left and right speakers. If they have to go on the ceiling, they should be no more than one-eighth of the distance to the middle of the room and at about 45 degrees of vertical elevation. Dolby notes that this changes the original Dolby Pro Logic IIz documentation, which said front heights should not sit inside the left and right mains. For rear heights, Dolby gives about 30 degrees horizontal on the rear wall, or about 135 degrees if placed overhead. A placement guide that summarizes Dolby's tables lists top front at 30 to 45 degrees azimuth and 45 to 55 degrees elevation, top rear at 135 to 150 degrees azimuth, and top middle at 65 to 100 degrees azimuth and 80 to 90 degrees elevation.

Worked example, using Dolby's seated ear height of 3.9 feet (1.2 m). With a 9 foot ceiling, a ceiling speaker rises 5.1 feet above the ears. A 45 degree elevation puts it 5.1 feet in front of the listener, and 55 degrees puts it about 3.6 feet in front. A wall-mounted front height behaves differently. Mounted 7 feet up the front wall and 10 feet from the seat, it rises 3.1 feet above ear level, an elevation of about 17 degrees, well below the 45 degrees Dolby cites for ceiling speakers. That gap in elevation is the geometric reason Dolby ranks ceiling speakers above wall front heights.

How the AVR treats the two labels

AVRs ask for the speaker type and location, then the Atmos renderer maps objects to the speakers it knows about. Dolby's guide tells installers to complete this setup step so that Atmos audio objects are accurately placed. The Pioneer VSX-LX805, for example, labels its extra amplifier channels Height 1 and Height 2, with Height 1 and 2 each as left and right pairs. Marantz uses the Height versus Top vocabulary above. A speaker labeled wrongly gives the renderer the wrong geometry, so for a ceiling speaker choose a Top setting and for a wall speaker choose a Height setting.

Front height vs top front: which is better

Dolby's guide is direct: most AVRs support front height speakers for Atmos, but Dolby recommends either overhead or Dolby Atmos enabled speakers for the most lifelike and enveloping result. Front heights can be used together with overhead speakers in larger installations that have enough height outputs. The rule for overhead placement is that the speakers should be at least two times the height of the listener's ear level, and overhead speakers with wide dispersion, roughly 45 degrees from the reference axis from 100 Hz to 10 kHz, can face straight down.

Ceiling height decides the practical answer. Dolby says that when a ceiling is low or overhead speakers are on trusses or brackets, they may be too close to you, and the sound may draw attention to each speaker instead of feeling like atmosphere. In that case Dolby Atmos enabled speakers may be a better solution. For enabled speakers the ceiling should be flat, 14 feet (4.27 m) or lower, and reflective, with an ideal height between 7.5 and 12 feet (2.3 to 3.66 m). For a standard 8 foot room that is the range to aim for.

Common confusions

Front height and front wide are different: Dolby lists the left and right wide pair separately from its overhead pairs, while front heights are height positions above the mains. Top front and top middle are different positions: in a 5.1.2 system Dolby's setup page shows a single pair of top middle overhead speakers above the seating, while 7.1.4 uses four overhead speakers. A front-height pair is not the same as a Dolby Atmos enabled speaker, which is a reflecting module. And the number after the second dot counts height speakers, not subwoofers; see channel configuration notation. The site's entry on height speaker elevation angle covers the angle itself, and Dolby enabled speakers and Atmos height virtualization cover the alternatives. Dolby allows up to 34 speaker positions in a layout such as 24.1.10, so a typical 7.1.4 room uses only a small part of the specification.