BMW 320i Rear Deck Lid Speaker Size
The BMW 320i rear deck lid accommodates a 1 inch speaker size and 4 inch units, as well as 5.25 inch speakers. Compatible types across all years include tweeters, midrange units, midbass units, and full-range audio components. These specifications cover vehicles from 1977 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 |
| 1983 | Midbass / Full-Range | 5.25 |
| 1982 | Midbass / Full-Range | 5.25 |
| 1981 | Midbass / Full-Range | 5.25 |
| 1980 | Midbass / Full-Range | 5.25 |
| 1979 | Midbass / Full-Range | 5.25 |
| 1978 | Midbass / Full-Range | 5.25 |
| 1977 | 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 rear deck lid is a horizontal surface positioned at the base of the rear window, behind the rear seats, placing speakers in an elevated rearward position relative to the cabin's listening area.
- Mounting on a deck lid surface typically involves shallow or semi-flush installation, as the panel thickness and underlying trunk structure limit the available depth for speaker baskets.
- The BMW 320i rear deck lid accommodates 2 distinct speaker size configurations across the listed model years: 1 inch and 4 inch for the 2013-2018 generation, and 5.25 inch for the 1977-1983 generation.
- A 1 inch tweeter operates in the high-frequency range, typically from around 2,000 Hz up to 20,000 Hz or beyond, and the small diaphragm diameter is well suited to reproducing treble detail with wide horizontal dispersion from the deck lid's rearward position.
- Because the deck lid sits behind the occupants, the wide dispersion of a 1 inch tweeter helps project high-frequency content forward into the cabin rather than concentrating it at the rear of the vehicle.
- A 4 inch midrange driver handles the vocal and instrumental frequency band, generally from approximately 500 Hz to 5,000 Hz, covering the core of speech intelligibility and melodic content.
- The 4 inch cone diameter allows adequate surface area for midrange output while remaining compact enough to fit within the constrained panel geometry of a rear deck lid.
- The pairing of a 1 inch tweeter and a 4 inch midrange in the 2013-2018 BMW 320i rear deck lid indicates a multi-driver configuration at that location, requiring each driver to be crossed over to its respective frequency band rather than operating as a single full-range source.
- A 5.25 inch driver in a midbass or full-range role covers a broad frequency span, typically from the upper bass range around 80-100 Hz through midrange frequencies, with full-range variants extending further into the treble.
- The 5.25 inch diameter provides a larger cone area than the 4 inch midrange, which translates to greater efficiency at lower frequencies and higher overall acoustic output from the rear deck position.
- When a 5.25 inch driver operates in a midbass role at the rear deck lid, the placement behind the occupants positions low-to-mid frequency output at the rear of the soundstage, which can reinforce bass body in the cabin due to boundary effects from the adjacent rear window and cabin walls.
- In a full-range application, a single 5.25 inch driver at the rear deck lid handles both midrange and treble reproduction without a separate tweeter, a configuration consistent with the simpler audio systems found in the 1977-1983 model years listed in the specifications.