2018 BMW 440i Speaker Sizes

The 2018 BMW 440i factory audio system features a center dash, front door panel, rear, and rear side panel which accommodate 1 inch speakers. Below seats support an 8 inch speaker size. Additionally, center dash, front door panel, rear, and rear side panel accept 4 inch units. Compatible speaker types for a replacement and upgrade include tweeter, midrange, and subwoofer.

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	1	Tweeter	Secondary sound location Medium replacement priority Replacement difficulty: medium
Rear	4	Midrange	Secondary sound location Medium replacement priority Replacement difficulty: medium
Rear Side Panel	1	Tweeter	Requires trim removal Medium replacement priority Replacement difficulty: medium
Rear Side Panel	4	Midrange	Requires trim removal Medium replacement priority Replacement difficulty: medium

2018 BMW 440i Speaker Replacement Summary

9 total positions

2 easy to replace

2 high priority

0 professional only

Replacement difficulty:

Low: 2 Medium: 7 High: 0

Replacement priority:

High: 2 Medium: 5 Low: 2

Additional Notes

The 2018 BMW 440i factory audio system appears to utilize a multi-way speaker configuration with dedicated tweeters, midrange drivers, and subwoofers distributed throughout the cabin rather than full-range coaxial speakers.
Tweeters measuring 1 inch are positioned in four locations: the center dash, front door panels, rear area, and rear side panels to handle high-frequency reproduction.
Midrange drivers at 4 inches occupy the same four locations as the tweeters, suggesting a component-style setup where each position uses separate drivers for different frequency ranges.
An 8-inch subwoofer located below the seats handles low-frequency output, which is relatively compact compared to aftermarket subwoofer installations.
Replacing the tweeters and midrange drivers with aftermarket component speakers of matching sizes could potentially improve clarity, detail, and dynamic range compared to the factory units.
The separate tweeter and midrange configuration allows for targeted upgrades, where owners might prioritize replacing one type of driver based on specific sonic deficiencies they wish to address.
Aftermarket component speakers rated for 4 inches would need to fit within the factory mounting locations while maintaining proper acoustic alignment with the corresponding 1-inch tweeters.
The under-seat subwoofer location may limit the depth and enclosure volume available for aftermarket subwoofer replacements, potentially restricting options for enhanced bass output.