BMW 440i Rear Speaker Size
The BMW 440i rear location supports a 1 inch speaker size and 4 inch speakers, accommodating 2 unique sizes across the rear placement. Compatible types for the rear audio system include tweeters and midrange units. These specifications cover the 2017 to 2018 model 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 speaker location in the BMW 440i accommodates 2 distinct speaker sizes simultaneously, indicating a multi-driver configuration rather than a single full-range installation.
- A 1-inch driver at the rear position operates within the high-frequency range, typically reproducing sounds from approximately 2,000 Hz to 20,000 Hz, where short wavelengths require a small diaphragm for accurate transient detail.
- Tweeters rely on compact, lightweight diaphragms to move rapidly at high frequencies, and the rear placement of a 1-inch tweeter in the BMW 440i contributes to the high-frequency component of the rear soundstage.
- The 4-inch driver occupies the midrange role in the rear location, covering the frequency band roughly between 300 Hz and 5,000 Hz, which includes fundamental vocal frequencies and a wide range of instrumental harmonics.
- A 4-inch cone diameter produces enough surface area to move air efficiently in the mid frequencies without the mass penalties that would impair high-frequency response, making midrange the acoustically appropriate designation for a driver of that size.
- Midrange drivers are designed to handle the frequencies where human hearing is most sensitive, and rear-cabin placement of a 4-inch midrange contributes ambient and spatial fill to the overall cabin sound field.
- The rear location separates the 1-inch and 4-inch drivers by type, meaning high and mid frequencies are reproduced by dedicated components rather than a single coaxial driver, which requires crossover filtering to divide the signal appropriately between the 2 drivers.
- The spatial constraints of the rear installation must accommodate both the 1-inch tweeter and the 4-inch midrange as distinct mounting points, implying separate cutout dimensions and potentially different mounting depths for each driver.
- The 4-inch mounting diameter defines a relatively compact installation footprint in the rear, which is consistent with secondary or fill speaker positions that supplement rather than anchor the primary acoustic stage.
- Both speaker sizes and their associated types remain consistent across the 2017 and 2018 model years, indicating no change to rear speaker bay dimensions or driver configuration between those 2 years.