BMW 740i Rear Deck Lid Speaker Size
The BMW 740i rear deck lid accommodates a 1 inch speaker size and 4 inch units, as well as 5.25 inch speakers. Compatible types across all positions include tweeters, midrange units, midbass, and full-range speakers. The specifications cover the years 2000 to 2018.
| Year | Type | Size (inch) |
|---|---|---|
| 2018 | Tweeter | 1 |
| 2018 | Midrange | 4 |
| 2017 | Tweeter | 1 |
| 2017 | Midrange | 4 |
| 2016 | Tweeter | 1 |
| 2016 | Midrange | 4 |
| 2015 | Tweeter | 1 |
| 2015 | Midrange | 4 |
| 2014 | Tweeter | 1 |
| 2014 | Midrange | 4 |
| 2013 | Tweeter | 1 |
| 2013 | Midrange | 4 |
| 2012 | Tweeter | 1 |
| 2012 | Midrange | 4 |
| 2011 | Tweeter | 1 |
| 2011 | Midrange | 4 |
| 2001 | Midbass / Full-Range | 5.25 |
| 2000 | Midbass / Full-Range | 5.25 |
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. |
| Midbass | A driver tuned for upper bass and lower midrange, roughly from 80 Hz to 500 Hz. It has longer cone travel than a full-range unit, which supports stronger bass in doors and panels. |
| Full-Range | A single driver that reproduces bass through treble without a separate crossover network. It is the simplest replacement option and is common in factory audio systems. |
Additional Notes
- The BMW 740i rear deck lid is a horizontal surface positioned at the rear of the cabin, typically spanning the width of the trunk opening beneath the rear window. Speaker cutouts in a deck lid are oriented to project sound upward toward the cabin ceiling and rear glass.
- The rear deck lid location places speakers at a distance from front-seat listeners, making upper-frequency dispersion and midrange clarity particularly relevant for rear-cabin coverage.
- A 1-inch driver in the rear deck lid of the BMW 740i handles high-frequency reproduction, generally covering the range above approximately 2,000-3,000 Hz. At 1 inch, the diaphragm is small enough to move rapidly and accurately for treble detail without significant mass-related distortion.
- Tweeters in a deck lid position radiate high-frequency content upward and toward the rear window, which can reflect treble energy forward into the cabin. The rear glass acts as a reflective surface that influences how high-frequency sound reaches front and rear passengers.
- The 4-inch midrange driver in the BMW 740i rear deck lid occupies a mounting cutout sized for moderate cone area, allowing reproduction of the vocal and instrument presence range, typically from roughly 300 Hz to 5,000 Hz, depending on crossover configuration.
- A midrange driver in a deck lid location is spatially separated from low-frequency drivers, which is consistent with a system design where bass reproduction is handled elsewhere in the vehicle. The 4-inch cone area in a deck lid is sufficient for midband frequencies but not optimized for low-frequency extension due to both size and enclosure characteristics of the deck structure.
- The BMW 740i rear deck lid accommodates a 2-driver configuration in model years 2011 through 2018, with the 1-inch tweeter and 4-inch midrange occupying separate mounting positions within the same panel.
- A 5.25-inch driver in the rear deck lid, as specified for model years 2000 and 2001, occupies a larger mounting cutout than the 4-inch position used in later years. The greater cone area of a 5.25-inch driver supports a broader low-to-mid frequency range compared to a 4-inch driver in the same location.
- Midbass drivers operating in a deck lid position reproduce the frequency range bridging bass and midrange, approximately 80 Hz to 500 Hz. In a deck lid enclosure, the panel itself and any cavity beneath contribute to the acoustic loading of the driver, influencing low-end output.
- A full-range driver, as listed among compatible types for the 5.25-inch position in 2000 and 2001, is designed to cover a wide frequency spectrum within a single driver, from low-midrange through treble, without requiring a separate tweeter at the same location.
- The rear deck lid structure is typically a thin panel reinforced by the vehicle's bodywork, and the depth available for speaker basket clearance is constrained by the trunk cavity below and the deck surface above, making mounting depth a relevant physical consideration for speaker fitment.
- The transition from a single 5.25-inch midbass/full-range position in 2000-2001 to a paired 1-inch tweeter and 4-inch midrange configuration in 2011-2018 reflects a difference in the number and size of mounting cutouts present in the deck lid panel across those production periods.