F22 Level Two 4W Sound Package (676)


The 676 HiFi system has three main shortcomings – the amplifier, the speakers you have, and the tweeter speakers you don’t have. The signal to the amplifier is actually clean and unprocessed and is great to use, when used properly. The signal out of the amplifier is heavily pre-emphasized for the stock tweeterless system, and is basically useless.

Our Level One upgrade for the 676 system uses a medium-power amplifier and a lot of DSP-powered equalization to get better performance out of the speakers (we also add in the missing BMW tweeters). Level Two goes in a completely different direction – we use better speakers, with much better crossover networks, and then we upgrade the amplification by more than triple. We don’t use DSP – instead of forcing the speakers to behave better by pre-emphasizing their signal, we use speakers which electromechanically “want” to behave better, because they are better speakers!

The 4-way system uses the underseats as band-pass crossover-filtered dedicated midbass drivers, and adds a trunk subwoofer in our OE-Look Enclosure. This gives you the immediacy and impact that 8-inch woofers in the floor can give you, combined with the true sub-bass available from a corner-loaded trunk subwoofer.

We provide an amplifier prepped to bolt into the stock provisions, and plug into the stock wiring harness. A power flow harness to the battery ensures that we make more wattage to the new speakers than the stock amp could. We then provide upgraded speakers and crossover filters prepped to bolt in and plug into the stock provisions – completely reversible, and incredibly better-performing. We focus on the core six speaker drivers – the front tweeters, the front midranges, and the underseat woofers. The new tweeters are supplied premounted into F22 tweeter trims. The mono center we delete – it’s not helping tonally, and it’s not helping with the stereo illusion, because it’s only mono – and we delete the rear speakers as well. Rear speaker upgrades have a terrible ROI – it’s much harder to tell the difference between a stock rear speaker and an upgraded rear speaker than it is to tell the difference between new and stock front speakers – but a rear-speaker retain option is available (we only recommend it for cars with Rear PDC alerts, or if you listen to predominantly club-intended recordings from the rap and hip-hop or techno and electronica genres).





The tweeters in Level Two are 28mm silk-dome units from Morel of Israel. They have the proper outer diameter to use BMWs OEM tweeter mounts, but their performance is far greater. Their upper extension is far more linear, allowing more “air” and “sparkle” without the brightness of “bite” which plague lesser tweeters in these cars. Their mechanical resonant frequency is low enough in the midrange that we can play the tweeter almost two octaves lower than most. (It helps that a 28mm dome has about 28% more area than a 25mm dome, which is the factory driver size).  This means the tweeter plays all the treble – we don’t rely on the midrange cone driver to play any of the treble, and that’s a preferred approach.

The midrange driver is in the 4-inch/100mm class of speakers, but a close inspection reveals that it, too, has a greater diameter than most speakers in its class. Morel tooled their own frame, cone, and surround (no off-an-Asian-shelf parts here) and the result is 24% more cone area than most 4-inch-class drivers. The use of a 50mm voice-coil winding means that an amplifier with enough power can exert more control over the motion of the cone than with most speakers. The magnet exists inside that 50mm diameter, not outside it as with most speakers, and that allows the magnet to actually fit inside the door! The magnet is a neodymium hybrid, which allows it to be small enough to fit and strong enough to do the job we need.  We modify it with our own mounting adapters and harnessing prep.

The woofers we import from Germany – 200mm woofers with neodymium magnets, paper-pulp cones, and our prep to both bolt in and plug in to replace the stock underseat woofers. (Many folks on the Internet call the underseat speakers “subwoofers”, but they are really playing a lot of middle bass and not that much sub-bass, so “woofer” is a much more accurate term.

The 6-channel amplifier powers the front, rear, and underseat woofers on 3 pair of channels. The front and rear speaker sets are high-passed (the bass is filtered out) and the underseat woofers are low-passed filtered (the mids and highs are filtered out). We set the crossover filters up so that the underseat woofers play regardless of fader position – we sum the front and rear bass notes together to create a “constant-bass” arrangement.