2011 BMW 135i Speaker Sizes

The 2011 BMW 135i speaker size chart details factory audio specifications and locations for replacement or aftermarket upgrade purposes. Information includes speaker locations in the front door panel, rear deck lid, rear side panel, and below seats. The chart provides technical specifications to help identify compatible aftermarket speakers for the factory system.

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Speaker Details by Location
Location Size Type Notes
Below Seats 8 Subwoofer
  • Very limited height clearance
  • Medium replacement priority
  • Replacement difficulty: medium
Front Door Panel 1 Tweeter
  • Standard installation
  • High replacement priority
  • Replacement difficulty: low
Front Door Panel 4 Midrange
  • Standard installation
  • High replacement priority
  • Replacement difficulty: low
Rear Deck Lid 1 Tweeter
  • Access through trunk
  • Medium replacement priority
  • Replacement difficulty: low
Rear Deck Lid 4 Midrange
  • Access through trunk
  • Medium replacement priority
  • Replacement difficulty: low
Rear Side Panel 1 Tweeter
  • Requires trim removal
  • Medium replacement priority
  • Replacement difficulty: medium
Rear Side Panel 4 Midrange
  • Requires trim removal
  • Medium replacement priority
  • Replacement difficulty: medium

2011 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: 0

Replacement priority:

High: 2 Medium: 3 Low: 2

2011 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 2011 BMW 135i utilizes a component speaker configuration with separate tweeters and midrange drivers rather than full-range coaxial speakers.
  • Tweeters are positioned in three locations throughout the cabin, with 1 inch units found in the front door panels, rear deck lid, and rear side panels.
  • Midrange drivers complement the tweeters across the same three locations, with 4 inch units installed in the front door panels, rear deck lid, and rear side panels.
  • An 8 inch subwoofer positioned below the seats handles low-frequency reproduction in the factory audio configuration.
  • Upgrading the midrange speakers may provide more noticeable sonic improvements than tweeter replacement, given their larger surface area and broader frequency range responsibilities.
  • Component speaker systems typically offer better soundstage and imaging compared to coaxial designs due to the physical separation of high and mid-frequency drivers.
  • Aftermarket speakers matching these sizes would need to accommodate the vehicle's existing mounting points and electrical connections.
  • The factory subwoofer location below the seats suggests a space-efficient design that preserves trunk and passenger area while still providing bass extension.
  • The radio accepts both single DIN and double DIN head unit replacements, offering flexibility for audio system upgrades.