BMW 230i Rear Side Panel Speaker Size
The BMW 230i rear side panel accommodates 1 inch speaker size and 4 inch speakers. Compatible types for the audio system include tweeter and midrange replacement 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 side panel location in the BMW 230i accommodates 2 distinct speaker sizes, 1 inch and 4 inch, each assigned to a different driver type.
- A 1-inch tweeter in the rear side panel operates in the high-frequency range, typically reproducing sounds from around 2,000 Hz up to 20,000 Hz, where short wavelengths benefit from a small driver diameter.
- The rear side panel placement of a tweeter contributes to high-frequency dispersion within the cabin's rear acoustic field, distributing treble detail toward rear seat occupants.
- A 4-inch midrange driver is suited to frequencies generally spanning from around 300 Hz to 5,000 Hz, where cone surface area and excursion characteristics handle vocal and instrumental reproduction without the mass limitations of larger woofers.
- The 4-inch diameter of the midrange unit reflects the spatial constraints typical of rear side panel cavities, where depth and width are limited by door or panel structure.
- Mounting a midrange driver at the rear side panel positions mid-frequency energy toward the rear seating zone, distinct from front-stage driver placement.
- The BMW 230i rear side panel accepts both a 1-inch tweeter and a 4-inch midrange as separate, co-located drivers rather than a single full-range unit, indicating a multi-driver configuration at this position.
- A 1-inch tweeter's compact form factor allows placement within the same panel section as the 4-inch midrange without significant structural modification to the rear side panel housing.
- The midrange driver at 4 inches lacks the cone area to reproduce deep bass frequencies effectively, which is consistent with a role limited to mid-frequency reproduction in a split-driver panel installation.
- Both the 1-inch tweeter and the 4-inch midrange specifications apply identically across the 2017 and 2018 model years of the BMW 230i for the rear side panel location.