1999 BMW 328is Speaker Sizes
The 1999 BMW 328is factory audio system includes rear deck lid locations that accept a 4 inch speaker size, front kick panel locations that accommodate 5.25 inch units, and front door panel locations that support 6x8 inch units. Compatible speaker types for replacement and upgrade include midrange, midbass, and full-range units.
Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.
| Location | Size | Type | Notes |
|---|---|---|---|
| Front Door Panel | 6x8 | Full-Range |
|
| Front Kick Panel | 5.25 | Midbass |
|
| Rear Deck Lid | 4 | Midrange |
|
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: 0Replacement priority:
High: 1 Medium: 2 Low: 01999 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.