BMW 640i xDrive Rear Side Panel Speaker Size
The BMW 640i xDrive rear side panel accommodates a 1 inch speaker size and 4 inch speakers. Compatible types for the audio system include tweeters and midrange units. The specifications cover a range from 2014 to 2018.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Tweeter | 1 |
| 2018 | Midrange | 4 |
| 2017 | Tweeter | 1 |
| 2017 | Midrange | 4 |
| 2016 | Tweeter | 1 |
| 2016 | Midrange | 4 |
| 2015 | Tweeter | 1 |
| 2015 | Midrange | 4 |
| 2014 | Tweeter | 1 |
| 2014 | 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 640i xDrive accommodates 2 distinct speaker sizes: 1 inch and 4 inch, each assigned to a specific driver type.
- The rear side panel position places speakers within the cabin's side walls toward the rear seating area, a location that influences both the dispersion angle and the spatial imaging perceived by rear passengers.
- A 1-inch tweeter in the rear side panel handles high-frequency reproduction, typically covering the range above 2,000 Hz, where directional sensitivity is heightened and placement along the side wall affects stereo imaging for rear occupants.
- The 4-inch midrange driver at the rear side panel is sized to reproduce frequencies generally spanning the 300 Hz to 5,000 Hz range, covering the core of vocal and instrumental content that contributes most to perceived sound clarity in the cabin.
- A 4-inch cone diameter in a midrange application limits low-frequency extension compared to larger woofer formats, making the driver suited for mid-band duties without encroaching on bass reproduction responsibilities.
- The 1-inch tweeter format at the rear side panel position produces a relatively wide high-frequency dispersion pattern, which at a side-mounted location can help distribute treble energy across the rear cabin space rather than concentrating it in a narrow beam.
- The BMW 640i xDrive rear side panel accepts both a 1-inch tweeter and a 4-inch midrange simultaneously, indicating the location contains 2 separate mounting points or a dual-driver housing arrangement.
- The midrange driver's side panel placement positions the 4-inch cone to project sound laterally into the rear cabin, a geometry that differs from a forward-facing door or dashboard mount and affects the perceived directionality of the mid-frequency content.
- The 1-inch and 4-inch size pairing at the rear side panel spans a combined frequency range that together covers mid and high frequencies, with the crossover point between the 2 drivers typically falling in the upper midrange.
- Across all listed model years from 2014 through 2018, the rear side panel speaker configuration remains consistent at 1 inch for tweeter and 4 inch for midrange, indicating no change in the mounting dimensions or driver type assignments over the production span covered by the specifications.