BMW 640i Gran Coupe Rear Door Panel Speaker Size
The BMW 640i Gran Coupe rear door 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 2013 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 |
| 2013 | Tweeter | 1 |
| 2013 | 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 BMW 640i Gran Coupe rear door panel accommodates 2 distinct speaker sizes per installation year: a 1 inch position and a 4 inch position.
- Door panel speaker locations are typically recessed within the door trim, with mounting depth and baffle dimensions constrained by the door cavity and interior panel thickness.
- A 1 inch tweeter in the rear door panel handles high-frequency content, generally in the range of approximately 2,000 Hz to 20,000 Hz, where short wavelengths allow a compact driver to reproduce transients and upper harmonic detail.
- Tweeters at this size exhibit relatively wide dispersion at the frequencies handled, which affects how high-frequency sound radiates across the rear cabin seating area from the door panel position.
- The 4 inch midrange driver in the BMW 640i Gran Coupe rear door panel operates across the vocal and instrumental midband, typically covering frequencies from roughly 300 Hz to 5,000 Hz.
- A 4 inch cone driver in a door panel location benefits from the door cavity acting as a partial enclosure, which can influence the low-frequency extension and overall output of the midrange driver.
- Midrange drivers at 4 inches produce a relatively focused dispersion pattern compared to larger woofers, which is relevant to how sound from the rear doors reaches passengers seated in the rear.
- The rear door panel placement positions both the tweeter and the midrange driver at a low height relative to rear seat occupants, which affects the angle and directness of sound projection toward the listening area.
- The pairing of a 1 inch tweeter alongside a 4 inch midrange in the same door panel indicates a 2-way speaker arrangement at the rear door location, where each driver handles a separate portion of the audible frequency spectrum.
- The mounting cutout required for a 4 inch midrange driver constrains the usable door panel surface area and must accommodate the driver's frame diameter and depth within the door structure.