BMW 328xi Rear Side Panel Speaker Size
The BMW 328xi rear side panel accommodates a 0.75 inch speaker size and 4 inch speakers. Compatible types for the rear side panel include tweeter and midrange audio units. These specifications cover the 2007 system model year.
| Year | Type | Size (inch) |
|---|---|---|
| 2007 | Tweeter | 0.75 |
| 2007 | 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 2007 BMW 328xi accommodates 2 distinct speaker sizes, each assigned to a separate driver type within the same spatial zone.
- A 0.75 inch tweeter installed at the rear side panel of the 2007 BMW 328xi operates in the high-frequency range, typically reproducing frequencies above 2,000 Hz, where directional sensitivity and transient detail are the primary acoustic concerns.
- At 0.75 inches, the tweeter diaphragm is small enough to move rapidly and accurately at high frequencies, minimizing distortion in the upper register from a rear-mounted position.
- Placement of a tweeter at the rear side panel contributes to the spatial and ambient character of the soundstage, as high-frequency content from rear positions adds perceived width and depth to the listening environment inside the cabin.
- The 4 inch midrange speaker at the BMW 328xi rear side panel is sized to handle the mid-frequency band, generally spanning approximately 300 Hz to 5,000 Hz, covering fundamentals and harmonics of most musical instruments and vocals.
- A 4 inch driver in a midrange role lacks the cone area required for significant bass reproduction, so low-frequency content below the midrange band falls outside the acoustic responsibility of a speaker of that size at the rear side panel.
- Midrange drivers at rear side panel positions reinforce the presence and body of sound within the passenger compartment, supplementing front-stage drivers in a multi-speaker configuration.
- The rear side panel location typically places speakers within door or quarter panel cavities, where enclosure volume, baffle material, and proximity to reflective surfaces directly influence the acoustic output of both the tweeter and the midrange driver.
- The physical separation between the 0.75 inch tweeter and the 4 inch midrange within the rear side panel requires a crossover arrangement, whether passive or active, to route appropriate frequency bands to each respective driver.