The '07 BMW 335i Convertible's Logic7 audio system sets a new standard in top-down sound.
GETTING GREAT SOUND IN A RAGTOP HAS ALWAYS BEEN TOUGH. But with a recent crop of hardtop convertibles, car companies have raised the bar on sound quality along with the roof. The Dynaudio premium sound system in the Volvo C70, for example, set a new standard for top-down OEM sound when it was introduced last year. Now the '07 BMW 335i Convertible with a Harman/Kardon Logic7 system sets a new benchmark.
The car I tested (sticker price $57,225) stood out as not only one of the best stock sound systems I've heard in a convertible, but also one of the best OEM systems period, whether the top was up or down. Amazingly, the BMW 335i Convertible's Harman/Kardon Logic7 system is standard equipment, not an option. Even more amazing is that it outperforms premium systems that add thousands of dollars to the sticker -- and even aftermarket systems I've heard in convertibles that cost thousands more.
The system consists of 13 speakers powered by a mere 300 watts. It's anchored by an AM/FM/CD radio in the dash that's rather sparse on controls but is nonetheless simple to operate. The display is small and low in the dash, but its bright orange LED readout is easier to read than those in some convertibles with even larger displays located higher in the dash, such as the Volvo C70 and the Chevy Corvette.
COMING 'ROUND THE MOUNTAINS
During a 300-mile-plus roundtrip through Oregon's Cascade mountain range, I got ample opportunity to sample the system with the top up and down using the same music on the same stretches of road. While cruising down the southern slope of Mt. Hood with the top up, for example, I listened to my all-time SQ favorite, Bluesiana Triangle, a pristine jazz/blues recording. I've heard this disc on hundreds of systems and know the nuances of every note.
While the 335i Convertible didn't reproduce the music perfectly, its performance was easily on par with the best stock car audio systems I've heard. The soundstage's parameters were higher than the dash, wider than the car and deeper than the interior, while imaging was for the most part accurate if not pinpoint. Midbass was exceptionally tight and accurate, highs were smooth and low bass hum was suitable. At higher volumes, however, the low bass began to distort and I could detect a slight bit of high-frequency harshness. Driving the same stretch of road in the opposite direction the next day, this time with the top down, I was amazed that very little of the sound quality was gone. Only the sub-bass had slightly less punch and the highs were masked by some of the road and wind noise, but this was at speeds between 70 and 80 mph.

BEND THERE
After picking up a musician friend in Bend, we cruised up Mt. Bachelor with the top down and Prince's all-instrumental 2003 CD N.E.W.S cranked. The low throb of the bass guitar that kicks off the opening track had a visceral impact, and when the saxophone wafted in a minute or so into the track, it was as if the horn player was sitting on the hood. We played the same track on the ride back down with the top up and confirmed that there was little difference in response.
Like many higher-end stock audio systems, the 335i Convertible uses DSP and simulated surround sound processing. Whereas some of these schemes detract rather than enhance the sound, adding an artificial, echo-like quality, the DSP in the 335i gave the music a realistic spaciousness. The system also plays MP3 music files burned onto CD and displays artist and song info. Plus, there's an auxiliary input in the center console for plugging in an iPod or other portable music player.
An onboard Bluetooth hands-free system makes it easy to connect and use a phone without taking your hands off the wheel. Steering wheel mounted controls activate the system and mute the stereo. But talking hands-free with the top down is a challenge because of the wind noise.
TWIN-TURBO TUNES
At times during my drive I was just as happy between tracks listening to the rev the 335i Convertible's 3.0L in-line six, especially when the twin turbos kicked in. According to BMW, the 300hp engine propels the 4,023-pound car from 0-60 in 5.8 seconds and I know from experience that the double-pivot suspension allows it to cling to twisty mountain roads like a leech.
But each time the tunes would kick back in I'd marvel at what an awesome sound system BMW created for this "Ultimate Driving Machine." And I'd even go a little further and proclaim that BMW and Harmon/Kardon created the ultimate open-air music machine.