2007 BMW 328i Speaker Sizes

Speaker size chart for the 2007 BMW 328i includes factory specifications and locations for replacement speakers. Information covers speaker positions in front door panels, rear door panels, center dash, rear side panels, rear deck lid, and below seats. Details include sizes compatible with aftermarket upgrades to the audio 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
Center Dash 4 Midrange
  • Requires dashboard disassembly
  • 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 Door Panel 0.75 Tweeter
  • Standard installation
  • Medium replacement priority
  • Replacement difficulty: low
Rear Door Panel 4 Midrange
  • Standard installation
  • Medium replacement priority
  • Replacement difficulty: low
Rear Side Panel 1 Tweeter
  • Requires trim removal
  • Medium replacement priority
  • Replacement difficulty: medium
Rear Side Panel 0.75 Tweeter
  • Requires trim removal
  • Medium replacement priority
  • Replacement difficulty: medium
Rear Side Panel 4 Midrange
  • Requires trim removal
  • Medium replacement priority
  • Replacement difficulty: medium

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: 0

Replacement priority:

High: 2 Medium: 6 Low: 3

2007 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.