18/12/2025
A nice OEM upgrade completed with competition like results!
A 2021 BMW X5 G05 with a standard HiFi sound system got a hell of an upgrade - STEG BM8II underseat midbass speakers, STEG BM45CII in the front doors is pretty nice already, but we didn't stop there:
The front doors got converted to a full active setup with extra cable runs to them - all through OEM BMW pins via the original door plug, without cutting, modifying or drilling anything.
The tweeters got their own channels in the new DSP amplifier and the system went from 7-channel to a 10-channel with the addition of the brand new Awave DSP-10D MAX and an extra STEG DST-401 amplifier for the original center channel (essential for stuff like emergency assist, sat nav, handsfree etc.) and the dual 10" subwoofer under the trunk floor.
Talking about the subwoofer under the floor - a custom, model specific sandwich style MDF box was used with two times 18L volumes plugged by two STEG ST10 subwoofers. Wired in series at 4 Ohm fed by 2 bridged channels on the DST-401.
The installation had to be immaculate, so no holes, no cuts, no wires were touched at all - everything uses the OEM plugs, OEM holes and OEM mounting points. Fully reversible.
All wiring was done according to competition standards, braided and color coded, with wire ferrules and hydraulic crimped copper connectors. The subwoofer has an inline XT60 connection as a quick disconnect when extra room for luggage is required, the tweeters have XT30 connections in the doors AND in the rear next to the amplifiers, so everything can be easily unplugged and taken out if maintenance has to be done (or if the OEM amplifier needs to be reconnected temporarily for ECU coding - something rarely thought of).
The amplifiers got mounted on a custom made bracket - laser cut and TIG welded out of 304 stainless steel - bent brackets can be out of tolerance, so we opted to TIG weld them with a 3D printed jig all designed in CAD with a reference to a 3D scan of the area. Again, with zero modifications to the car or its modules.
And finally the tune - a meticulous tuning session using our JL Audio MAX system, followed by refinement by ear, resulting in competition like technical competency with all left/right/center/left center/right center positioning being perfect on top of the dash and well focused, sonic balance done without over-EQ-ing the system, amazing dynamics achieved from such a relatively simple setup. Sound quality at quiet levels is as clean and smooth as at concert levels where the driver and passenger can't hear each other even shouting as loud as they can. No distortion, no sweat from the system. There's a lot more in it, but we decided to set it up so that at max volume the listeners don't get hearing damage - concert levels but without the ear ringing.
The end result is nothing short of amazing - fully competent system, both technically and sonically, with amazing dynamics which is also fully invisible without removing panels and covers. A true reference OEM install.
The system design was done by us, custom brackets and wiring all done by us, component installation was done at a BMW licensed high end service center, and of course the tuning was done by us as well. The joy of listening to music on this system will belong to the vehicle's owner and everyone lucky enough to get a demo.
