The D4 has a wider dispersion than the larger models. The high performance D4 is a true coaxial loudspeaker with a real compression driver concentrically arranged so that the upper frequencies emerge through the center of the low-frequency driver?s magnetic structure and cone via a precisely tapered Tru-Phase? high-frequency waveguide. This special construction provides consistent, wide dispersion up to 16 kHz, all but eliminating high-frequency narrowing. Further pattern improvement is achieved by precisely mounting the low frequency driver (and its concentric HF driver) centered in the baffle, as contrasted to the offset designs used by others.
The D SERIES offers powerful magnetic structures and efficient coils to ensure high output, which results in more headroom per power amplifier. The D4 is available as a complete assembly, including everything needed for standard installations, and can also be ordered as separate faces and back cans. The model has a built-in autoformer allowing it to be used in 8-ohm or 70V/100V applications. The D SERIES ceiling loudspeakers are ETL listed and all models have been tested by ETL to comply with UL1480, UL2043 and CSA60065.