2015 BMW 328i Speaker Sizes

The 2015 BMW 328i factory audio system features center dash, front door panel, rear deck lid, and rear door panel locations that accommodate 1 inch speakers and 4 inch units, alongside below seats locations that accept an 8 inch speaker size. Compatible speaker types for a sound replacement upgrade consist of tweeters, midranges, and subwoofers.

Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.

Speaker Details by Location
Location	Size	Type	Notes
Below Seats	8	Subwoofer	Very limited height clearance Medium replacement priority Replacement difficulty: medium
Center Dash	1	Tweeter	Requires dashboard disassembly 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	1	Tweeter	Standard installation Medium replacement priority Replacement difficulty: low
Rear Door Panel	4	Midrange	Standard installation Medium replacement priority Replacement difficulty: low

2015 BMW 328i Speaker Replacement Summary

9 total positions

6 easy to replace

2 high priority

0 professional only

Replacement difficulty:

Low: 6 Medium: 3 High: 0

Replacement priority:

High: 2 Medium: 7 Low: 0

2015 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 2015 BMW 328i employs a multi-way speaker configuration with dedicated tweeters, midrange drivers, and a subwoofer positioned across different locations throughout the cabin.
All tweeter locations accept 1-inch units, suggesting a uniform high-frequency reproduction strategy across the center dash, front door panels, rear deck lid, and rear door panels.
Midrange drivers are standardized at 4 inches across the same four locations that house tweeters, indicating a component-style separation of frequency ranges rather than coaxial full-range speakers.
The subwoofer location below the seats accommodates an 8-inch driver, which may provide bass reinforcement without requiring trunk space allocation.
Replacing the factory midrange drivers could potentially yield noticeable improvements in vocal clarity and instrumental detail, as these handle the critical middle frequencies where most musical content resides.
The separated tweeter and midrange configuration allows for independent upgrades of high and mid-frequency components, offering flexibility in sound customization compared to integrated coaxial designs.
Aftermarket component speaker sets with 1-inch tweeters and 4-inch midrange drivers would likely integrate directly into the existing mounting locations without extensive modification.
The radio opening supports both single DIN and double DIN head units, providing options for aftermarket stereo installation if source unit upgrades are considered alongside speaker replacements.