BMW 740Le xDrive Rear Deck Lid Speaker Size
The BMW 740Le xDrive rear deck lid location accommodates both 1 inch speaker size and 4 inch speakers. Compatible types across the location include tweeter and midrange audio units. These specifications cover the 2017 model year.
| Year | Type | Size (inch) |
|---|---|---|
| 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 deck lid of the BMW 740Le xDrive is a structural panel positioned at the rear of the cabin, typically integrating speakers into a surface that faces upward and rearward toward the passenger compartment.
- A deck lid location places speakers in a relatively shallow mounting environment, where depth clearance behind the mounting surface is often limited by the trunk structure and sealing mechanisms of the lid itself.
- The 1-inch tweeter listed for the 2017 BMW 740Le xDrive rear deck lid handles high-frequency reproduction, generally covering the range above 2,000 Hz, where wavelengths are short enough that small diaphragm size remains acoustically effective.
- At 1 inch, the tweeter diaphragm moves very little air but does so rapidly, making the driver well-suited for reproducing transient detail such as cymbal decay and upper vocal harmonics at the rear deck position.
- Tweeters are highly directional at the upper limits of their frequency range, meaning the mounting angle and surface orientation of the deck lid directly influence how high-frequency energy is distributed into the rear cabin.
- The 4-inch midrange driver listed for the 2017 model occupies the middle portion of the audio spectrum, typically operating between approximately 300 Hz and 5,000 Hz, covering fundamental vocal frequencies and a wide range of instrumental tones.
- A 4-inch cone diameter provides enough surface area to move sufficient air for midrange output without requiring the enclosure depth that larger woofer drivers demand, making the size practical for the constrained geometry of a deck lid mounting location.
- Midrange drivers are less directional than tweeters across most of their operating range, allowing a deck lid-mounted 4-inch driver to disperse sound broadly into the rear passenger area.
- The combination of a 1-inch tweeter and a 4-inch midrange at the rear deck lid indicates a two-way speaker arrangement at that location, where each driver is assigned a distinct frequency band rather than a single full-range driver covering the entire spectrum.
- The deck lid's position above and behind the rear seats places both drivers at a distance and angle from front-seat occupants, which affects the perceived soundstage contribution of the rear deck relative to speakers mounted closer to the listening position.