The audio system in this BMW X4M was as straight forward as it gets. Make a great sounding car within the footprint of the OEM audio system. Keep the car functional and stock looking. Put all of the budget into the performance of the audio system. With most BMW’s sharing the same speaker layout, it was quite simple to plan.
Starting with the front stage, we recreated the tweeter sail panels to house Focal Utopia M TBM tweeters. With the Utopia M tweeters being much larger than the factory, it made it to be the most challenging project of the entire build. With the OEM grill removed, the mounts were cut and a new mount to house the Utopia tweeter was molded in with Duramix 42/40. They were then sanded, polyprimered and repainted. The Harmon Kardon badge was then grinded down, sanded and polished. They were then laser etched with the Focal badging for an OEM look. The door panels and inner housing was removed to apply Sound Shield acoustic treatment to the outer door skin. New mounts were made to house the Focal Utopia M midrange speakers. The mid bass speakers were then replaced with the Focal plug and play under the seats.
The brains of the audio system were ran from a Helix V Twelve DSP amplifier. This gave use the ability to run the front 3 way speaker set active, along with the rear door speakers and rear fill speakers. The V Twelve allows a DSP preamp output which powered a Helix P One mono amplifier. This ran a JL Audio 13TW5 subwoofer which was in a custom stacked enclosure to fit perfectly into the spare tire area. The enclosure was finished off with black carpet and our Musaic system ID badge. A vent was made on the OEM amplifier access panel to allow air to move while creating additional space to mount the amplifiers.
We had three separate presets which were all controlled through the Helix Conductor DSP controller. Preset 1 drove the factory radio, which was interfaced with a Helix SDMI25. Preset 2 was using the HEC BT adapter directly housed into the amplifier. This is a aptX HD capable Bluetooth streaming chip. Preset number 3 connected to our Audioquest analog input for a Astell & Kern SP2000. All in all, a great well staged sounding system which uses all OEM locations. This was absolutely the best OEM location BMW system I have heard to date.