2011 BMW 128i Speaker Sizes
The 2011 BMW 128i factory audio system contains specific speaker locations that accept various components. Front door panels, rear deck lids, and rear side panels accommodate 1 inch units and 4 inch speakers, while below seats support an 8 inch speaker size. Compatible speaker types for a system replacement and upgrade consist of tweeters, midrange units, and subwoofers.
Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.
| Location | Size | Type | Notes |
|---|---|---|---|
| Below Seats | 8 | Subwoofer |
|
| Front Door Panel | 1 | Tweeter |
|
| Front Door Panel | 4 | Midrange |
|
| Rear Deck Lid | 1 | Tweeter |
|
| Rear Deck Lid | 4 | Midrange |
|
| Rear Side Panel | 1 | Tweeter |
|
| Rear Side Panel | 4 | Midrange |
|
2011 BMW 128i Speaker Replacement Summary
7
total positions
4
easy to replace
2
high priority
0
professional only
Replacement difficulty:
Low: 4 Medium: 3 High: 0Replacement priority:
High: 2 Medium: 3 Low: 22011 BMW 128i 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 2011 BMW 128i audio system incorporates a three-way component speaker configuration with separate tweeters, midrange drivers, and subwoofers positioned throughout the cabin.
- Front door panels house both 1-inch tweeters and 4-inch midrange speakers, suggesting a dedicated high-frequency and mid-frequency reproduction setup in the forward soundstage.
- Rear audio coverage includes tweeters and midrange speakers in both the deck lid and side panels, with all units maintaining the same 1-inch and 4-inch sizing as their front counterparts.
- An 8-inch subwoofer located below the seats handles low-frequency output, which may provide bass reinforcement without consuming traditional trunk or cabin space.
- The radio receiver supports both single DIN and double DIN head unit installations, potentially allowing for aftermarket upgrades with varying feature sets and display sizes.
- Replacing the factory tweeters could enhance clarity in the upper frequency range, particularly for vocals and cymbal detail that might otherwise sound muted or lacking presence.
- Upgrading the 4-inch midrange drivers might improve vocal reproduction and instrumental tonality, as these speakers typically handle the critical frequency range where most musical content resides.
- The under-seat subwoofer position suggests a space-conscious design approach, though this placement may produce different bass response characteristics compared to rear-mounted or trunk-installed configurations.
- Component speaker systems with separate tweeters and midrange units generally offer better soundstage imaging and frequency separation than full-range coaxial designs.
- Aftermarket speaker upgrades would need to maintain the specified sizes while potentially offering improvements in sensitivity ratings, power handling capacity, and frequency response range.