1999 BMW 328is Speaker Sizes

The 1999 BMW 328is speaker size chart provides factory audio specifications for replacement and upgrade purposes. Information includes speaker locations within the vehicle, such as front door panels, front kick panels, and rear deck lid positions. Aftermarket audio system planning requires knowledge of factory speaker specifications and mounting locations to ensure proper fitment during installation.

As an Amazon Associate, we may earn a commission from purchases made through links marked. Read more in our disclaimer.

Speaker Details by Location
Location Size Type Notes
Front Door Panel 6x8 Full-Range
  • Standard installation
  • High replacement priority
  • Replacement difficulty: low
Front Kick Panel 5.25 Midbass
  • Cramped working position
  • Medium replacement priority
  • Replacement difficulty: medium
Rear Deck Lid 4 Midrange
  • Access through trunk
  • Medium replacement priority
  • Replacement difficulty: low

1999 BMW 328is Speaker Replacement Summary

3 total positions
2 easy to replace
1 high priority
0 professional only

Replacement difficulty:

Low: 2 Medium: 1 High: 0

Replacement priority:

High: 1 Medium: 2 Low: 0

1999 BMW 328is 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 1999 BMW 328is features three distinct speaker locations with varying sizes and purposes, suggesting a tiered approach to audio system upgrades based on listening priorities and budget constraints.
  • Front door panel speakers utilize 6x8 inch full-range drivers, which handle the broadest frequency spectrum among the three locations and would likely provide the most noticeable improvement in overall sound quality when replaced.
  • Midbass drivers in the front kick panels measure 5.25 inches and focus on lower midrange frequencies, potentially enhancing vocal clarity and the lower end of instrumental reproduction without requiring subwoofer integration.
  • The rear deck lid houses 4 inch midrange speakers that concentrate on middle frequencies, serving more as fill speakers to create soundstage depth rather than primary output sources.
  • Full-range speakers in the front doors handle bass, midrange, and treble frequencies within a single unit, offering a simpler upgrade path compared to component systems that separate these frequency ranges.
  • The kick panel location for midbass drivers may provide better stereo imaging than door-mounted speakers due to positioning that directs sound more toward the listening area.
  • Aftermarket speaker selection for the 1999 BMW 328is would need to account for both standard round formats (4 inch, 5.25 inch) and the less common 6x8 inch oval configuration in the doors.
  • The combination of single DIN and double DIN radio compatibility indicates that head unit upgrades could accompany speaker replacements for comprehensive audio system modernization.
  • Sound improvement priorities might favor addressing the front door and kick panel speakers before the rear deck, given their larger sizes and roles in primary sound reproduction versus ambient fill.