The Dodge Monaco rear deck lid accommodates a 6x9 inch speaker size across all listed model years. Compatible types for the location include full-range audio system units. These specifications cover the 1990 to 1992 range of model years.
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 is a horizontal surface located at the top of the trunk compartment, positioned beneath the rear window. Speakers mounted in a rear deck lid fire upward toward the cabin, with sound reflecting off the rear glass and dispersing into the passenger area.
A 6x9 inch speaker occupies a relatively large footprint, requiring a mounting cutout that accommodates an oval frame measuring approximately 6 inches by 9 inches, along with sufficient depth clearance beneath the deck surface to house the driver basket without contacting trunk components below.
The 6x9 inch oval format produces a larger cone surface area than round 6.5 inch equivalents, which increases low-frequency displacement and allows the driver to move more air within the rear deck lid cavity.
The Dodge Monaco rear deck lid accommodates 6x9 inch drivers across the 1990, 1991, and 1992 model years, indicating a consistent mounting cavity geometry throughout the production span covered in the specifications.
Full-range is the only compatible speaker type listed for the Dodge Monaco rear deck lid, meaning the specified drivers are designed to reproduce the entire audible frequency spectrum - typically from approximately 50 Hz to 20 kHz - from a single driver unit.
A full-range driver at the 6x9 inch size relies on its larger cone for extended low-frequency output while a dust cap or whizzer cone integrated into the design handles upper-midrange and treble reproduction at the rear deck lid position.
Placement at the rear deck lid means the drivers are physically distant from the front occupants, which at higher frequencies introduces directionality concerns, since treble wavelengths are short enough to beam in a narrow pattern rather than disperse broadly through the cabin.
The upward-firing orientation of rear deck lid speakers means low and midrange frequencies, which are largely omnidirectional, travel forward into the cabin with relatively even distribution, while high-frequency output from the full-range driver depends on cabin reflections for front-seat audibility.