BMW 440i xDrive Rear Side Panel Speaker Size
The BMW 440i xDrive rear side panel accommodates 1 inch speaker size and 4 inch speakers. Compatible types for the location include tweeters and midrange units. The specifications cover the 2017 to 2018 range of years.
| 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 side panel location in the BMW 440i xDrive accommodates 2 distinct speaker sizes, 1 inch and 4 inch, each assigned to a separate driver type.
- A 1-inch tweeter in the rear side panel operates in the high-frequency range, typically reproducing sounds from approximately 2,000 Hz up to 20,000 Hz, contributing to the presence and airiness of audio perceived from the rear cabin area.
- Tweeters at 1 inch are physically small by design, as high-frequency wavelengths are short and do not require a large diaphragm surface to reproduce accurately, making the rear side panel a spatially feasible mounting point for such a driver.
- The 4-inch midrange driver in the rear side panel handles the middle portion of the audible spectrum, generally spanning from around 300 Hz to 5,000 Hz, which covers fundamental vocal frequencies and a large portion of instrument body tones.
- A 4-inch cone diameter reflects a balance between the panel space available in a rear side panel cavity and the surface area needed to move enough air for midrange reproduction without encroaching on subwoofer or tweeter territory.
- Rear side panel locations are typically recessed into the interior trim between the rear door and the rear seat area, orienting the speaker drivers toward the cabin rather than directly at seated listeners, which affects the dispersion pattern of both the tweeter and midrange.
- The BMW 440i xDrive rear side panel in both the 2017 and 2018 model years accepts the same 1-inch and 4-inch speaker dimensions, indicating dimensional consistency in the mounting cutout and depth across those 2 model years.
- Midrange drivers, unlike tweeters, require a moderate amount of cone excursion to reproduce lower-midrange frequencies, and the rear side panel mounting depth must be sufficient to accommodate the basket depth and magnet structure of a 4-inch midrange unit.
- Tweeters in a rear side panel position contribute to rear-stage soundstage width and high-frequency fill, as high-frequency sounds are highly directional and benefit from multiple placement points throughout the cabin.
- The separation of the 1-inch tweeter and the 4-inch midrange into distinct drivers at the rear side panel indicates a component-style speaker arrangement rather than a single coaxial unit at that location.