What we researched for this specific generation: where an enclosure actually fits, what the factory speakers are, how the factory audio is wired, and which real builds and commercial products exist for it. Confidence badges say how well each figure is sourced — this is research, not manufacturer spec.
Body styles covered: 4-Door SUV
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | underseat (both HK and B&W tiers) |
|---|---|
| Outer bounding box | factory sealed OEM unit, no aftermarket-facing raw dimension published |
| Known obstructions | The B&W-specific subwoofer part is electronically and physically exclusive to that trim — confirmed NOT interchangeable with the HK or base HiFi systems |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | aftermarket sub in the cargo area, separate from the factory underseat unit |
|---|---|
| Box type | aftermarket, cargo area |
| Location | cargo area (leaving the factory underseat sub in place) |
| Subwoofers | OEM B&W underseat subwoofer (65132622510) if upgrading from HiFi/HK to full B&W trim-level hardware, or cargo-area custom build for more output than either factory tier delivers |
|---|---|
| Box type | factory or custom |
| Location | underseat (factory) or cargo area (custom) |
Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.
| Adapter bracket needed | unconfirmed |
|---|---|
| Tweeter | In the mirror triangles, not the door: BMW's UK equipment list puts "2 tweeters in the mirror triangles" plus one centre tweeter in the instrument panel on both the Hi-Fi (676) and Harman Kardon (688) systems; no size given. The Bowers & Wilkins system lists two 25 mm Diamond Nautilus tweeters and five 25 mm aluminium tweeters around the car. UK-market list dated 03/12/2019; the US list was not read. |
| Midrange | Front door trims: BMW's UK equipment list puts "2 midrange speakers in the front door trims" on both the Hi-Fi (option 676) and Harman Kardon (option 688) systems; no size given. The Bowers & Wilkins system lists seven 100 mm Kevlar midrange speakers around the car without saying which sit in the doors. UK-market list dated 03/12/2019; the US list was not read. |
| Adapter bracket needed | unconfirmed |
|---|---|
| Tweeter | Rear door trims, Harman Kardon system only: BMW's UK equipment list puts "2 tweeters in the rear door trims" on option 688, with the harman/kardon designation; the Hi-Fi system (676) lists no rear tweeters. No size given. UK-market list dated 03/12/2019; the US list was not read. |
| Midrange | Rear door trims: BMW's UK equipment list puts "2 midrange speakers in the rear door panels" (Hi-Fi, option 676) and "2 midrange speakers in the rear door trim" (Harman Kardon, option 688); no size given. UK-market list dated 03/12/2019; the US list was not read. |
| Factory amp / premium audio | Two confirmed premium tiers: Harman Kardon (16 speakers, 9 channels, 464W, standard on xDrive50i/M50i) and Bowers & Wilkins Diamond Surround (20 speakers, top tier). Confirmed OEM part number for the B&W underseat subwoofer: 65132622510 — explicitly confirmed NOT compatible with the base HiFi or Harman Kardon systems, a genuine trim-locked part. BMW's own figures: Hi-Fi (option 676) 10 speakers, 205 W. Harman Kardon (option 688) 16 speakers, 9 channels, 464 W, with speakers in the centre instrument panel (tweeter and midrange), the mirror triangles (tweeters), the front and rear door trims (midrange, plus rear tweeters), the D-pillar (midrange and tweeters) and 2 central bass speakers under the front seats. Bowers & Wilkins Diamond Surround (option 6F1): 2 x 25 mm Diamond Nautilus tweeters, 5 x 25 mm aluminium tweeters, 7 x 100 mm Kevlar midrange, 4 x 40 mm 3D mid-tweeters, and a 1,475 W 20-channel amplifier. CONFLICT: BMW's US launch release says "20 speakers and 1,500-watt output"; BMW's UK list and B&W's own page say 1,475 W. Positions are from BMW's UK list; the US list was not read. |
|---|---|
| Adding subs without a head-unit swap | Confirmed possible via the cargo area as an aftermarket-add location, separate from the factory underseat subs — real BIMMERPOST threads discuss B&W retrofit attempts on non-B&W cars (pre-LCI, amp-based rather than RAM-based electrical architecture is a prerequisite, per owner findings). |
| Head unit | No replacement needed |
Precise factory spec confirmed via Go-Parts.com's own dedicated diagnostic guide: this generation offers Harman Kardon (16 speakers, 464W, 9-channel DSP amp — standard on xDrive50i/M50i trims) as the mid tier, and Bowers & Wilkins Diamond Surround (20 speakers, diamond-domed tweeters, overhead channels) as the top tier. BOTH tiers use an UNDERSEAT subwoofer location, not a trunk-mounted design — a specific difference from most other SUVs, which mostly use cargo-area/spare-tire-well subs. Owner sentiment: even with underseat subs on both tiers, reviewers note the bass 'doesn't fully satisfy owners in an interior as large as the X5' — a real critique of the factory low end, not just a spec sheet.
Outside links. Some are commercial products, some are owner builds posted on forums — the label says which. We do not endorse any of them.
Each link opens the tool with this vehicle already selected.
Measure your own vehicle. Trim levels, factory subwoofer options, and mid-generation changes all move these numbers, and a box cut to a researched figure that does not match your truck is wasted wood. Where a badge reads Unconfirmed, treat the value as a starting point for your own measurement, not as an answer.