BMW 640i xDrive Gran Coupe Rear Side Panel Speaker Size
The BMW 640i xDrive Gran Coupe rear side panel location accommodates a 4 inch speaker size. Midrange units are the compatible type for audio reproduction in the rear side panel. These specifications apply to the 2018 model year.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Midrange | 4 |
Speaker Types
| Type | Description |
|---|---|
| Midrange | A driver for the middle of the audible range, typically from about 300 Hz to 5,000 Hz, where vocals and most instruments sit. It is often paired with a tweeter and a woofer. |
Additional Notes
- The rear side panel location in the BMW 640i xDrive Gran Coupe accommodates a 4-inch speaker driver within the panel cavity of the vehicle's rear side structure.
- A 4-inch driver in a rear side panel position operates within a constrained enclosure volume, where the panel depth and available airspace behind the mounting surface directly affect low-frequency extension and cone excursion.
- The 4-inch diameter indicates a relatively compact cone area, which limits the driver's ability to move large volumes of air and consequently focuses acoustic output toward the mid and upper portions of the frequency spectrum rather than bass reproduction.
- Midrange drivers are designed to reproduce frequencies roughly between 300 Hz and 5,000 Hz, covering the range where vocals, instruments, and much of speech intelligibility are concentrated.
- In the rear side panel location of the BMW 640i xDrive Gran Coupe, the midrange type designation means the driver is intended to handle the frequency band between the subwoofer or woofer range and the high-frequency tweeter range.
- A 4-inch midrange driver at the rear side panel position contributes to the rear soundstage's tonal body, filling the frequency range that gives voices and acoustic instruments their natural character and presence.
- The rear side panel mounting orientation typically angles the driver toward the cabin interior, which affects the directional dispersion pattern of midrange frequencies and how listeners in rear seating positions perceive the sound.
- Because midrange drivers reproduce frequencies with relatively short wavelengths compared to bass drivers, the 4-inch cone size in the rear side panel is acoustically appropriate for the directional characteristics and spatial projection demands of that frequency band.