BMW 740e xDrive Rear Door Panel Speaker Size
The BMW 740e xDrive rear door panel accommodates a 1 inch speaker size and 4 inch speakers across all listed model years. Compatible audio types for these locations include tweeter and midrange replacement units. These specifications cover the 2017 to 2018 system range.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Tweeter | 1 |
| 2018 | Midrange | 4 |
| 2017 | Tweeter | 1 |
| 2017 | Midrange | 4 |
Speaker Types
| Type | Description |
|---|---|
| Tweeter | A small driver built for high frequencies, typically from about 2,000 Hz to 20,000 Hz. It adds treble detail and clarity and is usually mounted near ear level or aimed at the listener. |
| 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 740e xDrive accommodates 2 distinct speaker sizes, a 1 inch and a 4 inch, each assigned to a separate compatible type.
- Rear door panels in full-size sedans typically situate speakers within a recessed cavity in the lower or mid-section of the door card, where available depth and baffle area influence which driver diameters fit without modification.
- A 1 inch tweeter handles high-frequency reproduction, generally covering the range above approximately 3,500 Hz to 5,000 Hz and above, where transient detail, shimmer, and vocal air reside in an audio signal.
- Placement of a 1 inch tweeter in the rear door panel positions high-frequency dispersion toward rear-seat occupants, which serves spatial imaging and acoustic balance within the cabin rather than forward-stage projection.
- The small physical diameter of a 1 inch tweeter corresponds to a short, lightweight diaphragm capable of rapid pistonic movement, which is mechanically necessary to reproduce the fast pressure variations of high-frequency waveforms accurately.
- A 4 inch midrange driver reproduces the middle portion of the audible spectrum, typically spanning roughly 300 Hz to 5,000 Hz, a range that includes the fundamental frequencies of the human voice and many acoustic instruments.
- In the rear door panel of the BMW 740e xDrive, the 4 inch midrange driver operates in a location where door cavity volume and panel rigidity directly affect the quality and coloration of midband reproduction.
- A 4 inch cone diameter is physically compact relative to woofer-class drivers, which limits low-frequency extension but preserves directional clarity and controlled dispersion across the midrange band in a near-field cabin environment.
- Midrange drivers are designed to operate within a band where the human ear is most acoustically sensitive, meaning the 4 inch driver positioned in the rear door panel contributes substantially to perceived tonal presence for rear-seat listeners.
- Both the 1 inch tweeter and the 4 inch midrange specifications apply identically across the 2017 and 2018 model years of the BMW 740e xDrive rear door panel location.