BMW M4 Rear Side Panel Speaker Size
The BMW M4 rear side panel accommodates a 1 inch speaker size and 4 inch speakers. Compatible types for the location include tweeters and midrange units. The specifications cover the 2015 to 2018 model years.
| 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 |
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 M4 accommodates 2 distinct speaker sizes: 1 inch and 4 inch.
- The rear side panel is a fixed structural position within the cabin, meaning available depth and baffle area are constrained by the panel's molded geometry, which directly limits driver diameter to the 2 sizes listed.
- A 1-inch driver in the rear side panel position operates as a tweeter, handling high-frequency content typically above 2,000 Hz, where short wavelengths require a small diaphragm to maintain accurate dispersion.
- Tweeters in rear side panel locations contribute to the high-frequency component of the rear soundstage, reinforcing spatial detail and upper harmonic information as perceived from the listening position.
- The 4-inch driver in the BMW M4 rear side panel is designated for midrange use, covering frequencies generally between 300 Hz and 5,000 Hz, a range that includes vocals, instruments, and much of the tonal body of audio reproduction.
- A 4-inch midrange driver produces a relatively directional dispersion pattern at higher midrange frequencies, meaning placement angle and panel orientation within the rear side panel affect how sound reaches the front listening position.
- The 4-inch cone diameter limits low-frequency extension, as smaller diaphragms move less air volume, making the midrange designation acoustically appropriate for the physical size at this location.
- The pairing of a 1-inch tweeter and a 4-inch midrange in the rear side panel indicates a 2-way speaker arrangement at that location, requiring a crossover to divide the frequency spectrum between the 2 drivers.
- At 1 inch, the tweeter diaphragm is small enough to reproduce high frequencies without significant breakup or beaming artifacts that would occur with larger diaphragms at the same frequencies.
- The rear side panel position, being laterally mounted rather than forward-facing, influences the spatial character of both the tweeter and midrange output, as sound radiates toward the cabin interior at an oblique angle relative to the primary listening axis.