1989 BMW 735i Speaker Sizes
The 1989 BMW 735i factory audio system features a front kick panel that accommodates a 4x6 inch speaker size, while the rear deck lid can accept 5.25 inch units. Full-range and midbass units serve as compatible speaker types for an audio replacement and system upgrade.
Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.
| Location | Size | Type | Notes |
|---|---|---|---|
| Front Kick Panel | 4x6 | Full-Range |
|
| Rear Deck Lid | 5.25 | Midbass / Full-Range |
|
1989 BMW 735i 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 735i 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 front kick panel locations in the 1989 BMW 735i typically receive priority for replacement, as these positions handle most of the audible frequency range that reaches occupants in the cabin.
- Full-range speakers for the 4x6 inch openings would reproduce frequencies from approximately 60Hz to 20kHz without requiring separate tweeters or crossovers.
- The 5.25 inch rear deck lid positions could accept either midbass drivers focused on lower frequencies or full-range units depending on the desired system configuration.
- Midbass drivers in the rear would generally handle frequencies between 80Hz and 500Hz, complementing smaller front speakers that may lack low-frequency output.
- The 4x6 inch size represents an oval format that differs from round speaker designs, which affects mounting depth requirements and power handling characteristics.
- Aftermarket speakers with sensitivity ratings above 88dB would likely produce noticeable volume increases over factory units when powered by the stock head unit.
- Component speaker systems could be adapted to the front kick panel locations if the tweeters are mounted separately in the A-pillar or sail panel areas.
- The single DIN radio opening allows for straightforward replacement with contemporary head units that offer higher power output to drive upgraded speakers more effectively.
- Sound quality improvements would be most apparent in the midrange frequencies where vocal clarity and instrument separation become more distinct with higher-quality drivers.
- Coaxial speakers with integrated tweeters maintain a simpler installation process while still providing frequency response across the audible spectrum.