2013 BMW 135i Speaker Sizes
The 2013 BMW 135i factory audio system contains specific speaker locations. Front door panel, rear deck lid, and rear side panel accept 1 inch units and 4 inch speakers, while below seats accommodate an 8 inch speaker size. Compatible types for replacement and upgrade include tweeter, midrange, and subwoofer units.
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 |
|
2013 BMW 135i 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: 22013 BMW 135i 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 2013 BMW 135i audio system incorporates a component speaker configuration with separate tweeters and midrange drivers rather than full-range coaxial speakers, which typically allows for more precise sound staging and frequency separation.
- Tweeters at 1 inch are distributed across three locations including front door panels, rear deck lid, and rear side panels, suggesting a multi-point high-frequency dispersion strategy throughout the cabin.
- The 4-inch midrange drivers mirror the tweeter placement pattern with installations in front door panels, rear deck lid, and rear side panel positions, indicating a dedicated mid-frequency reproduction system independent of low-frequency handling.
- An 8-inch subwoofer positioned below the seats provides bass frequencies, which represents a space-efficient under-seat mounting approach that preserves cargo area while still delivering low-end audio response.
- Replacing the factory tweeters could be prioritized when seeking improved high-frequency clarity or detail, as these smaller drivers handle the most directional and delicate portions of the audio spectrum.
- The midrange speakers at 4 inches handle vocal and instrumental fundamentals, making them candidates for upgrade when midrange warmth or presence lacks definition in the stock configuration.
- Component speaker systems like this configuration generally benefit from matching tweeters and midrange drivers from the same manufacturer or product line to maintain coherent crossover characteristics and tonal balance.
- The under-seat subwoofer location may present thermal considerations since this position typically receives less airflow than trunk-mounted alternatives, potentially affecting long-term voice coil temperatures during sustained high-output playback.
- Both single DIN and double DIN radio compatibility provides flexibility for head unit replacement, with double DIN allowing for larger touchscreen interfaces while single DIN maintains a more traditional dashboard aesthetic.