BMW Alpina B7 xDrive Rear Door Panel Speaker Size
The BMW Alpina B7 xDrive rear door panel accommodates a 1 inch speaker size and 4 inch speakers. Compatible types for these locations include tweeters and midrange units. These specifications cover the 2013 to 2018 model years.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Tweeter | 1 |
| 2018 | Midrange | 4 |
| 2015 | Tweeter | 1 |
| 2015 | Midrange | 4 |
| 2014 | Tweeter | 1 |
| 2014 | Midrange | 4 |
| 2013 | Tweeter | 1 |
| 2013 | 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 door panel of the BMW Alpina B7 xDrive accommodates 2 distinct speaker sizes across the listed model years: 1 inch and 4 inch.
- Rear door panels are interior-mounted locations, meaning speakers are recessed into a vertical surface and directed toward the cabin occupants rather than firing into open air.
- A 1-inch tweeter in the rear door panel occupies a small cutout, typically near the upper section of the panel, positioning high-frequency output closer to ear level for rear-seat passengers.
- Tweeters in the 1-inch class reproduce high-frequency content, generally from around 2,000 Hz up to 20,000 Hz, handling the upper range of audible sound such as cymbals, string overtones, and vocal air.
- Because tweeters are highly directional at high frequencies, placement in the rear door panel aims dispersion toward the rear seating area rather than the front cabin.
- The BMW Alpina B7 xDrive rear door panel is specified to accept a 4-inch midrange driver, which fits within the mid-sized cutout dimensions typical of passenger door installations on full-size luxury sedans.
- A 4-inch midrange driver in the rear door panel reproduces the vocal and instrumental midrange band, generally spanning approximately 300 Hz to 5,000 Hz, covering the frequencies most critical to speech intelligibility and tonal body.
- Midrange drivers in the 4-inch class have limited low-frequency extension due to their small cone area, making them dependent on a woofer or subwoofer elsewhere in the system for bass reproduction.
- The pairing of a 1-inch tweeter and a 4-inch midrange in the same rear door panel constitutes a 2-way speaker arrangement at that location, dividing the frequency spectrum between the 2 driver types.
- Door panel installations are subject to panel resonance and cavity reflections from the internal door structure, which can influence the acoustic output of both the midrange and tweeter drivers mounted within.