1989 BMW 635CSi Speaker Sizes
The 1989 BMW 635CSi factory audio system contains specific factory mounting positions. Dashboard locations accept a 4 inch speaker size, while rear deck lid positions accommodate 6.5 inch units. Compatible speaker types for replacement and upgrade include midrange, midbass, and full-range.
Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.
| Location | Size | Type | Notes |
|---|---|---|---|
| Dashboard | 4 | Midrange |
|
| Rear Deck Lid | 6.5 | Midbass / Full-Range |
|
1989 BMW 635CSi Speaker Replacement Summary
2
total positions
1
easy to replace
0
high priority
0
professional only
Replacement difficulty:
Low: 1 Medium: 1 High: 0Replacement priority:
High: 0 Medium: 2 Low: 01989 BMW 635CSi Radio Slot Size (DIN)
| DIN Type | Size (inch) | Size (mm) | Notes |
|---|---|---|---|
| Single DIN | 7"×2" | 180×50 | Standard size for basic car radios with small display or no display |
- Always measure the slot before purchasing a new radio
- Check slot depth - it may vary
Additional Notes
- The 1989 BMW 635CSi features a two-location speaker configuration with 4-inch dashboard speakers designated for midrange frequencies and 6.5-inch rear deck speakers that accommodate either midbass or full-range drivers, suggesting the dashboard locations should be addressed first when upgrading the sound system.
- The 4-inch dashboard speakers in the 1989 BMW 635CSi are specifically designed for midrange reproduction, which typically handles vocal frequencies and instrumental detail between approximately 300Hz and 5000Hz, making these positions critical for maintaining clarity in the central listening area.
- The rear deck lid speakers accept 6.5-inch drivers with flexibility between midbass and full-range configurations, allowing owners to choose between dedicated bass reinforcement in the 80Hz to 500Hz range or speakers that cover a broader frequency spectrum without additional components.
- The single DIN radio opening provides standard compatibility with aftermarket head units, which may be necessary to properly drive upgraded speakers since factory amplification in this era was typically designed for lower sensitivity drivers.
- Replacing the dashboard midrange speakers could provide noticeable improvements in vocal presence and instrument separation, while the rear deck speakers would primarily affect low-frequency extension and overall system fullness depending on whether midbass or full-range drivers are selected.
- The component-style separation between midrange and midbass/full-range locations suggests that careful attention to crossover points and frequency distribution would be beneficial when selecting replacement speakers to avoid gaps or overlap in the sonic spectrum.