Focal ISUB BMW 2 Custom Fit 10 Under Seat Subwoofer for BMW. ISUB BMW 2 is a subwoofer that delivers powerful bass thanks to its neodymium engine, a high performing Focal technology. With ISUB BMW 2, the sound is neutral and the install is quick thanks to the spacer integrated in the chassis that allows perfect integration into the original location. With its 2 Ohms impedance, it is ideal with your original amplification. Sensitivity: (2.83V/1m) 83dB. No wire to cut, no modification. 100% compatible with your vehicle. Sound quality superior compared to the original one. Only available to UK and Ireland customers.