The Dodge Diplomat rear deck lid accommodates a 6x9 inch speaker size across all listed model years. Full-range units represent the compatible audio system type for the location. These specifications cover the years 1980 through 1989.
A single driver that reproduces bass through treble without a separate crossover network. It is the simplest replacement option and is common in factory audio systems.
Additional Notes
The rear deck lid of the Dodge Diplomat is the horizontal shelf located at the base of the rear window, above the trunk cavity, a position that places speakers firing upward toward the cabin's headliner and rear glass.
Mounting on a rear deck lid typically involves a flat or near-flat baffle surface, where the speaker cone faces vertically upward rather than directly toward the listening position of front or rear seat occupants.
The upward-firing orientation of a rear deck lid installation causes sound to reflect off the rear windshield glass before reaching the passenger cabin, which influences the perceived stereo imaging and spatial character of the audio.
The 6x9 inch oval format is a non-circular speaker shape engineered to maximize cone surface area within the constrained dimensions of a rear deck cutout, producing greater air displacement than a round speaker of comparable linear measurement.
Greater cone surface area in a 6x9 inch driver allows for higher acoustic output at lower frequencies relative to smaller formats, making the format well suited to the rear deck lid's position as a primary low-to-mid frequency source in the cabin.
The Dodge Diplomat rear deck lid accepts 6x9 inch speakers across all model years in the specifications, indicating a consistent cutout dimension and mounting hole pattern throughout that production span.
Full-range speakers are single-driver units designed to reproduce a broad portion of the audible frequency spectrum, typically spanning from the lower midrange through the upper treble, without requiring a separate crossover network or additional driver components.
In a rear deck lid location, a full-range driver handles bass, midrange, and treble reproduction from a single cone and dust cap assembly, with many 6x9 inch full-range designs incorporating a secondary whizzer cone to extend high-frequency output.
The rear deck lid's physical distance from front seat occupants means that high-frequency content, which is more directional and subject to greater distance-related roll-off than low frequencies, benefits from the extended treble response a full-range 6x9 inch driver is designed to produce.
The structural surface of a rear deck lid is generally constructed from pressed fiberboard or sheet metal, and the rigidity of the surrounding panel influences the degree of panel resonance that can interact with the speaker's low-frequency output at the 6x9 inch format's capable excursion range.