2007 BMW 328i Speaker Sizes
The 2007 BMW 328i factory audio system contains specific locations to accommodate audio components, such as rear door panel and rear side panel locations which accept 0.75 inch units, while front door panel and rear deck lid locations accept 1 inch units. Additionally, center dash, front door panel, rear deck lid, and rear door panel locations accommodate 4 inch speakers, and rear side panel locations accept a 8 inch speaker size. Below seats locations support subwoofers, while all mentioned locations support tweeters and midranges as potential replacement and upgrade options.
Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.
| Location | Size | Type | Notes |
|---|---|---|---|
| Below Seats | 8 | Subwoofer |
|
| Center Dash | 4 | Midrange |
|
| Front Door Panel | 1 | Tweeter |
|
| Front Door Panel | 4 | Midrange |
|
| Rear Deck Lid | 1 | Tweeter |
|
| Rear Deck Lid | 4 | Midrange |
|
| Rear Door Panel | 0.75 | Tweeter |
|
| Rear Door Panel | 4 | Midrange |
|
| Rear Side Panel | 1 | Tweeter |
|
| Rear Side Panel | 0.75 | Tweeter |
|
| Rear Side Panel | 4 | Midrange |
|
2007 BMW 328i Speaker Replacement Summary
11
total positions
6
easy to replace
2
high priority
0
professional only
Replacement difficulty:
Low: 6 Medium: 5 High: 0Replacement priority:
High: 2 Medium: 6 Low: 32007 BMW 328i Radio Slot Size (DIN)
| DIN Type | Size (inch) | Size (mm) | Notes |
|---|---|---|---|
| Single DIN or Double DIN | 7"×2" or 7"×4" | 180×50 or 180×100 | Vehicle supports both radio sizes |
- Always measure the slot before purchasing a new radio
- Check slot depth - it may vary
Additional Notes
- The 2007 BMW 328i factory audio system incorporates a multi-driver configuration with dedicated tweeters, midrange speakers, and subwoofers positioned throughout the cabin to create a distributed sound stage.
- Tweeters ranging from 0.75 inch to 1 inch are located in the front door panels, rear door panels, rear side panels, and rear deck lid, handling high-frequency reproduction across multiple listening positions.
- The 4-inch midrange drivers installed in the center dash, front door panels, rear door panels, rear side panels, and rear deck lid handle the critical mid-frequency range where most vocal content resides.
- An 8-inch subwoofer positioned below the seats provides low-frequency reinforcement, though this mounting location may limit bass output compared to traditional trunk-mounted installations.
- The radio opening accepts both single DIN and double DIN head units, allowing flexibility when upgrading the source component while maintaining factory integration.
- Replacing the tweeters may yield noticeable improvements in high-frequency clarity and detail, particularly if the factory silk dome units have degraded over time.
- The 4-inch midrange speakers represent a potentially significant upgrade path, as aftermarket components in this size class often offer enhanced cone materials, stronger motor structures, and improved frequency response compared to factory units.
- The multiple tweeter locations suggest the factory system was designed to provide consistent high-frequency coverage regardless of seating position, though this approach can sometimes create phase interference between drivers.
- Upgrading the below-seat subwoofer to an aftermarket 8-inch component with higher power handling and extended low-frequency response could enhance bass impact without requiring trunk space modifications.
- The midrange speakers in the door panels likely operate in a partially sealed environment, which may benefit from aftermarket units designed specifically for infinite baffle mounting conditions.