BMW 640i Gran Coupe Rear Deck Lid Speaker Size
The BMW 640i Gran Coupe rear deck lid accommodates a 1 inch speaker size and 4 inch speakers, representing the 2 unique speaker sizes found in the location. Compatible types for the rear deck lid include tweeter and midrange units, covering the full audio range for the system. The specifications span from 2016 to 2018.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Tweeter | 1 |
| 2018 | Midrange | 4 |
| 2017 | Tweeter | 1 |
| 2017 | Midrange | 4 |
| 2016 | Tweeter | 1 |
| 2016 | 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 deck lid of the BMW 640i Gran Coupe accommodates 2 distinct speaker sizes across the listed model years: 1 inch and 4 inch.
- The rear deck lid position places speakers within the rearmost section of the cabin, a surface area that sits behind the rear seating and beneath the rear window, orienting sound upward and forward into the passenger compartment.
- A 1-inch driver in the rear deck lid context operates as a tweeter, a speaker type dedicated to high-frequency reproduction, generally covering the range from approximately 2,000 Hz to 20,000 Hz.
- Tweeters of the 1-inch diameter are physically small, which allows a relatively stiff, lightweight diaphragm to move rapidly enough to reproduce high-frequency transients with acceptable accuracy at this location.
- The BMW 640i Gran Coupe rear deck lid tweeter placement positions high-frequency output behind occupants, a configuration where wide dispersion characteristics of small dome or cone tweeters help distribute treble energy throughout the cabin.
- The 4-inch driver at the rear deck lid position is designated for midrange use, covering the frequency band generally defined as approximately 300 Hz to 5,000 Hz, which encompasses a large portion of vocal and instrumental content.
- A 4-inch midrange driver has a cone area large enough to move sufficient air for mid-frequency output, yet small enough to maintain directional control and avoid the breakup modes associated with larger cone diameters at upper-midrange frequencies.
- Midrange drivers at the rear deck lid position direct mid-frequency energy upward toward the headliner and rear window, where reflective surfaces interact with the sound field inside the Gran Coupe's four-door fastback body style.
- The pairing of a 1-inch tweeter and a 4-inch midrange at the same installation location indicates a multi-driver configuration at the rear deck lid, requiring crossover filtering to divide the frequency spectrum between the 2 driver types.
- The 4-inch midrange designation at the rear deck lid excludes full-range or woofer applications, meaning low-frequency reinforcement is not a function assigned to the rear deck lid in the BMW 640i Gran Coupe's specified configuration.