Height channels are the difference between a surround system and an object-based one. This page covers Polk's height modules, the ceiling conditions that decide whether reflection will work, and how the layout notation translates into hardware.
A height module sits on top of a floorstanding or bookshelf speaker and fires upward, reflecting overhead sound from the ceiling. It needs its own amplified channel from the AV receiver. It works well under a flat, reasonably hard ceiling at a normal height; sloped, beamed, very high or heavily treated ceilings suit in-ceiling speakers better.
Height modules reproduce the overhead layer. Two modules give a 5.1.2 or 7.1.2 layout; four give 5.1.4 or 7.1.4, provided the AV receiver can process that many height channels simultaneously. The module does not connect to the speaker underneath it — it is an independent channel.
Values below are Polk's own published figures. Where a specification is not published, the cell reads "Specification currently being verified" rather than carrying an estimate. Each model has its own page with the full specification set, system role and installation notes.
| Model | Series | Drivers | Frequency response | Sensitivity | Detail page |
|---|---|---|---|---|---|
| ES90 | Signature Elite | 1 × 1" Terylene dome tweeter, 1 × 5.25" mica-reinforced polypropylene woofer | 142 Hz – 26 kHz (−3 dB); 52 Hz – 40 kHz (−10 dB) | 85 dB | View |
| R900 | Reserve | 1 × 0.75" Pinnacle Ring Radiator tweeter, 1 × 4" Turbine Cone woofer | 50 Hz – 50 kHz overall (wall-mounted); 70 Hz – 32 kHz (−3 dB) | 85.5 dB (2.83 V / 1 m, wall-mounted) | View |
| XT90 | Monitor XT | 1 × 4" bi-laminate paper woofer | 94 Hz – 22 kHz | 89 dB (1 W / 1 m) | View |
Selection is a room decision. These are the factors we work through before suggesting a model, in this order:
Modules sit on top of the front left and right, and on the surrounds for a four-height layout. The receiver has to be told the layout being used so that it processes and delays the channels correctly. We verify the result with Atmos demonstration content, listening for whether overhead effects arrive from above rather than from the front wall.
Most of the rooms we are asked to correct have the right equipment installed the wrong way. These are the recurring ones:
Each page lists manufacturer-published specifications, the model's role in a system, room and placement considerations, receiver matching and installation guidance.
Specifications on this page are taken from Polk Audio's own published product information and are re-checked before each content update. Where a value is not published by the manufacturer, we leave it out rather than estimate it — you will see "Specification currently being verified" instead of a guessed number. Everything else on this page is LiveInSmart's own system-design and installation guidance, written by the engineers who commission these rooms.
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Under a flat, hard ceiling at a normal height they are convincing. Where the ceiling is sloped, beamed, very high or acoustically absorbent, in-ceiling speakers are the more reliable choice.
Two for a .2 layout and four for a .4 layout, limited by how many height channels your receiver can process at once.
Some models can be wall-mounted, but that changes them into surround-type speakers rather than reflected height speakers. Check the specific model's mounting options.
Only with multi-channel music mixes or when an upmixer is engaged. Stereo playback normally uses the front pair alone.
It depends on depth and construction. A shallow, firmly fixed false ceiling reflects acceptably; a deep, flexible one absorbs and resonates. We assess it on site before recommending reflected height.
As an authorised Polk Audio dealer in Telangana and Andhra Pradesh, we can help with product selection, system design, installation and calibration. Send us your room dimensions, seating position, ceiling type and how you use the room for a room-appropriate configuration.
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