The Porsche 924 rear door panel accommodates a 4x6 inch speaker size. Full-range units represent the compatible audio system type for the rear door panel location. These specifications cover the 1987 to 1988 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 door panel location in the Porsche 924 accommodates a 4x6 inch speaker footprint, an oval format that fits within the constrained vertical and horizontal dimensions typical of smaller European sport coupe door cavities.
Oval speaker cutouts like the 4x6 inch format are commonly used in door panel positions where a circular speaker of equivalent cone area would not fit within the available mounting depth or panel geometry.
The 4x6 inch oval format produces a cone area that supports a broader frequency response than a smaller round driver, while still fitting within door panel recesses that restrict mounting depth and baffle width.
The Porsche 924 rear door panel, for both the 1987 and 1988 model years, is specified exclusively for full-range speaker types at the 4x6 inch size.
A full-range driver is a single transducer designed to reproduce low, mid, and high frequencies without a dedicated crossover network, making the driver solely responsible for the entire audible spectrum at the door panel location.
In a rear door panel position, a full-range driver handles both the direct and ambient components of the sound field, since the rear doors contribute to the perceived stereo width and rear-fill characteristics of the cabin.
The door panel mounting surface typically places the speaker baffle flush against or slightly recessed into the interior panel, which affects the front-to-back acoustic seal and influences how low-frequency energy from the 4x6 inch cone couples with the door cavity volume.
Door cavities in compact sports cars tend to have limited internal volume behind the speaker baffle, which affects the low-frequency extension a full-range 4x6 inch driver can achieve at the Porsche 924 rear door panel location.
The 4x6 inch oval geometry distributes cone excursion across a longer axis, which influences the dispersion pattern of mid and high frequencies emitted from the rear door panel position toward the cabin interior.