Pure Resonance Audio SD4 SuperDispersion Ceiling Speaker Array

If you have ever walked through a school hallway, a retail store, or a church lobby and noticed hot spots in the audio, loud in one corner and quiet in another, that is exactly the problem the Pure Resonance Audio SD4 SuperDispersion ceiling speaker array is built to solve.

The SD4 uses a four driver array with a 360° by 180° dispersion pattern to spread sound in a smooth hemisphere. In many real installs, one SD4 can cover roughly a 30 ft x 30 ft area (depending on ceiling height, ambient noise, and how loud you need it). That is the big win: fewer speakers, fewer ceiling cuts, less wire, and typically less labor, while still getting clear paging and better background music consistency.

This is also a flexible system design piece. The built-in 70V transformer gives you tap options from 4W up to 64W at 70V, so you can tune loudness per zone without reworking the whole system. If you are running a low-impedance setup, you can use the 8 ohm bypass. With 160W RMS power handling, 92 dB sensitivity, and a 45 Hz to 20 kHz response, it handles announcements cleanly and keeps music full enough for commercial spaces that want more than “thin ceiling speaker” sound.

Installation is straightforward for drop ceilings. You remove one tile, drop the SD4 into a standard 2x2 or 2x4 grid, connect speaker wire, then secure it using the included safety cables. The shallow backbox depth (2.8 inches) helps when plenum space is limited.

Where it fits best: classrooms, schools and universities, restaurants, retail stores, offices, houses of worship, government facilities, and anywhere you want wide coverage with a clean ceiling look. If you are planning around “commercial paging speakers,” “70V ceiling speakers,” or a “drop ceiling speaker array” that reduces speaker count, the SD4 is one of the most efficient ways to get there.

Benefits
You get more even room coverage with fewer speakers, which usually means lower install time and less ceiling work. You can dial in volume per zone with 70V taps, or run 8 ohm if that matches your amplifier plan. Voice paging stays intelligible across the space, and background music sounds consistent instead of patchy.

360° omnidirectional coverage, designed to fill the room evenly
Covers up to about 30 ft x 30 ft per speaker, application dependent
Built-in 70V transformer with 4W, 8W, 16W, 32W, 64W taps
8 ohm bypass option for low-impedance systems
Four 6.5 inch full-range drivers for wide, smooth output
160W RMS power handling with 92 dB sensitivity
Frequency response 45 Hz to 20 kHz for music plus clear voice paging
Fast install into standard 2x2 or 2x4 drop-ceiling grids
Includes safety cable kit, four steel cables, carabiners, fastlinks
Shallow backbox depth, 2.8 inches, for tight plenum spaces