BMW 228i Rear Side Panel Speaker Size
The BMW 228i rear side panel accommodates 1 inch speaker size and 4 inch speakers. Compatible types for these units include tweeter and midrange audio components within the system. These specifications cover a range from 2015 to 2016.
| Year | Type | Size (inch) |
|---|---|---|
| 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 228i accommodates 2 distinct speaker sizes simultaneously, indicating a multi-driver configuration within the same panel zone.
- A 1-inch tweeter mounted in the rear side panel operates in the high-frequency range, typically reproducing sounds from around 2,000 Hz up to 20,000 Hz, covering transient details such as cymbals, upper harmonics, and vocal air.
- The small diaphragm area of a 1-inch tweeter is acoustically suited to high-frequency reproduction because shorter wavelengths require less cone excursion and a smaller radiating surface to maintain directional accuracy.
- Rear side panel placement of a tweeter influences the spatial dispersion of high frequencies throughout the cabin, as the angle and proximity to the listening position affect stereo imaging and soundstage width for rear occupants.
- A 4-inch midrange driver in the rear side panel handles the middle portion of the audible spectrum, generally covering frequencies from approximately 300 Hz to 5,000 Hz, which includes the fundamental tones of most vocals and many acoustic instruments.
- The 4-inch cone diameter of the midrange driver is large enough to move sufficient air for mid-frequency projection but compact enough to fit within the dimensional constraints of a rear side panel cavity in the BMW 228i.
- Midrange drivers reproduce frequencies where human hearing is most sensitive, meaning the rear side panel position of a 4-inch midrange directly influences perceived vocal clarity and tonal balance for passengers in the rear seating area.
- The pairing of a 1-inch tweeter and a 4-inch midrange in the same rear side panel location indicates a passive or active crossover is required to divide the audio signal, directing high frequencies to the tweeter and mid frequencies to the 4-inch driver.
- The rear side panel is a structurally integrated trim surface, which means speaker depth and mounting flange diameter are constrained by the panel's internal cavity depth and the available cutout area behind the trim material.
- Both the 2015 and 2016 model years of the BMW 228i share identical rear side panel speaker size and type specifications, with 1-inch tweeters and 4-inch midrange drivers listed for both years.