About the Focal Inside ISUB BMW4

Add a kick to your BMW
Add a kick to your BMW
Designed in Germany for the ultimate driving experience, you know your BMW will own the road. But if the bass from your factory sub system isn't cutting it, add some Focal audio tech to the mix. The ISUB BMW 4 fits perfectly into the sub enclosure of select BMW models, providing a dramatic boost in the low frequencies of your music. Focal utilizes much of the same technology that they employ in their audiophile-grade home speakers, so you'll enjoy your time behind the wheel even more.
Top-notch materials and design
The ISUB BMW 4 is designed to work perfectly with your existing BMW's amplifier. The Polyglass woofer provides neutral and accurate sound, while the butyl rubber surround holds up over the long haul. Integrated connectors hook up to your existing factory speaker plugs — no cutting or splicing required.
Installation Note: In most cases, the new sub has the same screw hole pattern as the factory sub and is a perfect fit, but there are a few instances where the factory sub was glued in place and new screw holes need to be drilled in the plastic factory enclosure.
Subwoofer Wiring Diagrams
To see sample wiring diagrams for all common subwoofer/amplifier combinations, check out this informative article.
Product highlights:
- single 8" 4-ohm component subwoofer
- designed for specific BMW models
- Polyglass woofer cone
- butyl rubber surround
- neodymium magnet
- power handling: 90 watts RMS (180 watts peak)
- frequency response: 35-200 Hz
- sensitivity: 83 dB
- grille not included
- warranty: 1 year
- MFR # KIT ISUB BMW4
What's in the box:
Focal Inside ISUB BMW4 owner's manual
- 1 Subwoofer
- 1 Foam gasket
- Four 1" Screws
- User manual (English/ French/ German/ Italian/ Spanish/ Portugese/ Dutch/ Polish/ Russian/ Chinese/ Korean/ Japanese/ Arabic)
- Focal window sticker
- Adhesive backed Focal Inside badge
Reviews (1)
Customer reviews for Focal Inside ISUB BMW4
Loading reviews...
Average review:
4.0 out of 5 starsThanks for submitting your review
Customer photos
This review was collected as part of a promotion
Pros:
Cons:
More details on the Focal Inside ISUB BMW4

Features & specs
General | ||
---|---|---|
Speaker Size | Vehicle-specific | |
Design | 1-way | |
Tweeter Design | --- | |
Impedance (Ohms) | 4 | |
Tweeter Composition | --- | |
Woofer Composition | Polyglass/Paper | |
Woofer Surround | Butyl Rubber | |
Parts Warranty | 1 Year | |
Labor Warranty | 1 Year | |
Specifications | ||
Sensitivity (1W at 1 meter) | N/A | |
Sensitivity at 2.83 volts | 83 | |
Frequency Response | 35 - 0.2k Hz | |
Minimum RMS Wattage | --- | |
Maximum RMS Wattage | 90 | |
Peak Power Handling (Watts) | 180 | |
Top-mount Depth (Inches) | 1 7/16 | |
Bottom-mount Depth (Inches) | N/A | |
Cutout Diameter or Length (inches) | 7 7/16 | |
Mounting Height (Inches) | 0.91 |
Product Research
Features
Mounting: The ISUB BMW 4 is a direct replacement for the factory under-seat subwoofers in select BMW models. In most cases, the new sub has the same screw hole pattern as the factory sub and is a perfect fit, but there are a few instances where the factory sub was glued in place and new screw holes need to be drilled in the plastic factory enclosure. The factory grille is re-installed over the new subwoofer. This sub is packaged individually, so you will need to purchase two. Please enter your vehicle information to confirm fit.
Wiring: The BMW factory wiring harness plugs directly into the subwoofer frame.
Polyglass Cone: The subwoofer cone has a cellulose pulp base and is coated with a uniform deposit of hollow glass microballs. The addition of the Polyglass layer significantly increases the cone's rigidity without adding much weight. This combination takes advantage of the accuracy and neutrality of the hard outer surface, but maintains the superior damping characteristics of the cellulose pulp. The subwoofer has a built-in cover, so the cone isn't visible during installation.
Magnets: The sub uses a neodymium magnet to minimize size without giving up magnetic field strength.
Reinstalling Seats: When researching a previous generation BMW replacement subwoofer, I found a warning about not reconnecting the battery until the seats have been reinstalled and the wiring reconnected. The warning stated that reconnecting power too soon, to test the new subs, can damage the seats and airbags. I found no such warning related to this ISUB BMW 4 sub, but to be safe I recommend heeding the warning in this case as well.
Loading accessories...
Customer Q&A
Loading articles...