BMW 745Li Rear Door Panel Speaker Size
The BMW 745Li rear door panel accommodates a 4 inch speaker size across all model years. Compatible types for the location include midrange audio units, which represent the system's supported speaker category. These specifications cover the 2002 to 2005 model range.
| Year | Type | Size (inch) |
|---|---|---|
| 2005 | Midrange | 4 |
| 2004 | Midrange | 4 |
| 2003 | Midrange | 4 |
| 2002 | 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 door panel location on the BMW 745Li accommodates a 4-inch speaker diameter across the 2002 through 2005 model years.
- A 4-inch speaker occupies a relatively compact mounting footprint, which is consistent with the space constraints typical of door panel cavities in the rear passenger section of a full-size luxury sedan.
- Door panel installations are surface-flush or shallow-depth enclosures, meaning the rear door cavity on the 745Li functions as a semi-open baffle rather than a sealed or ported enclosure.
- The 4-inch cone diameter produces a limited radiating surface area, which concentrates its acoustic output in the upper-bass and midrange frequency bands rather than extended low-frequency reproduction.
- The sole compatible type listed for the BMW 745Li rear door panel is midrange, a speaker category engineered to handle approximately 500 Hz to 5,000 Hz with accuracy and low distortion.
- Midrange drivers are designed to reproduce the frequency band most associated with vocal intelligibility and the fundamental tones of many acoustic instruments.
- In a rear door panel position, a midrange driver projects sound toward the rear passenger cabin at an angle determined by the door's interior geometry, contributing to the overall soundstage perceived by rear-seat occupants.
- A 4-inch midrange in a door panel location benefits from the door's internal cavity volume, which can provide minimal acoustic loading even in the absence of a dedicated enclosure.
- The rear door panel placement positions the driver near the lower portion of the passenger seating area, affecting the vertical dispersion angle relative to ear level for seated rear passengers.