B&O On Location: Poster Presentation
In order to give us an opportunity to talk with some of the other members of the acoustics team, they had a "Poster" presentation ala Grad school. In a large room, tables were set up with little displays of a number of different products. I'll take you through a couple of the more interesting items.
Geoff Martin once again took center stage as he demonstrated how using two subs in stereo can increase the spaciousness of the sound reproduced. First using a pink tone and then music, Geoff flipped between mono, dual mono, and stereo presentation of subwoofer content. He started with a high crossover point and then reduced it down in a few steps to 120Hz. With the pink tone, it was easy to see how spaciousness was increased by the stereo subs even as low as 120Hz. With the music, I had a harder time hearing it. There are a few problems with this concept. First, it is hard enough to place two subs in a room much less place two equidistance on both sides (so you can take advantage of the stereo). Second, and more importantly, most music is recorded with mono bass (though classical music tends to have more widely spaced mics). You'd have to find a recording where the left and right channels used different mics placed sufficiently apart to garner a different bass response. While not impossible to find, it isn't very common either. Lastly, we feel that evening out the bass response in a room by reducing room modes is immensely more important to sound quality than stereo subwoofer imaging. In the ideal room, stereo subwoofers might be cool, but to the average listener, dual mono subs offer the greater advantage.
Audi A8 Speaker System
Shown off by Dirk Hogenfeld, Training and Event Manager in the Automotive department, the Audi A8 car audio system was by far the most popular exhibit regardless of the rain. Designed by Bang & Olufsen, this system sounds remarkably good for being inside a car. It consisted of 13 speakers and a subwoofer (totaling 14 speakers), 3 across the front, 2 in each of the four doors, and three across the back. There are presets for Driver, Front seats, Rear seats, and All. The tweeters (utilizing the Acoustic Lens Technology) popped out of the dash in the front corners. Each speaker is incased in its own box (rather than using the internal volume of whatever part of the car it is installed in) to control its frequency response and sound.
All told, the system sports over 1000 watts of power but when you step out of the car, even at earsplitting volumes, the sound is remarkably muted (a testimony to the Audi's ride and noise dampening material). Only the bass really escapes with any conviction. Inside, the demo highlighted how well the DSP works to create a soundstage for the intended audience. When focused on the Driver (where I was sitting), All, or the Front seat, I enjoyed a fairly convincing soundstage that was only slightly skewed left due to my proximity to the left tweeter and driver's side window. When Rear seat was chosen, the soundstage disintegrated considerably though the guys in the back seemed to be having a good time. All and all, I was pretty impressed. Currently, B&O only has systems in the high-end Audi's though they are looking to expand into other vehicles.
3M Littmann Electronic Stethoscope
Imagine my surprise when I saw a stethoscope on display. For the first time, I saw a product that wasn't branded by the iconic B&O logo. The 3M Littmann Electronic Stethoscope has the ability to reduce background noise, uses a DSP to focus solely on lung or heart noise (to the exclusion of the others), and can even take your heart rate. Apparently the stethoscope is sold pretty widely in the United States though I can't say I've ever noticed a doctor using one. Of course, I can't say I've looked all that closely either. The next time I visit the pediatrician, I'll ask about them.
Rub and Buzz Test Demo
During the Production Tour, we got to see the testing of the BeoLab 5. One of those tests was the "Rub and Buzz" test. To show how this test of harmonic distortion works, B & O had a driver in a box hooked up to a laptop. The box was dampened and there was a mic inserted through the top. The test started by running a test tone through the driver and taking a measurement. Then, a piece of a paperclip was taped on top of the driver and the test was run again. Even from outside the box you could hear the buzzing. The test took all of a couple of seconds and you could easily see on the laptop how poorly the driver failed the test (indicating that it could detect more subtle differences). They had a number of drivers on hand just in case one got damaged. The tech that was running the test looked all too eager to blow a couple of the drivers. The boys from Mythbusters would be proud.
Back at CEDIA, Yamaha was demoing the YSV-1 Multi Channel Headphone Preamp that simulated the surround sound of your home theater. Bang & Olufsen demoed a similar technology except it was designed to simulate automotive listening environments. The idea is to use this technology to ensure that the sound system in the Audi A8 can be replicated in other vehicles. While it shares the same basic idea with the Yamaha YSV-1, it utilizes a magnetic sensing system rather than IR. In the Yamaha demo, you had to be standing in a specific spot. With this, you could move the headphones anywhere and it would work. On the computer screen, you could see the model head moving in 3 dimensions though the sound would only change on the horizontal plane. They can also use the system to record actual road noise (not simulated) using a dummy head (not pictured) to make the recording. Basically, they can use this system to do blind listening tests for automotive systems (much like the curtain would be used in the listening rooms)
Dinner at the Olufsen's
After a short break (where I fed my jet lag by taking a nap), we were brought to dinner at the place where it all began - the Olufsen family farm. It was raining and icky that night but the home was no less impressive. Unfortunately, I couldn't really get exterior pictures but I did get a chance to photograph the inside. The small portion of the home that we had access to was still large by American standards and furnished with an eclectic mix of antiques and Bang & Olufsen equipment. Seeing a flat screen TV and a thin aluminum tube filled with drivers next to a grandfather clock and exquisitely inlaid furniture seemed befuddling at times. Still, the home was beautiful and Peter Skak Olufsen and his wife Susanne were gracious hosts. I must say that the meal was by far the best that I had while in Denmark. We were served shrimp salad, veal tenderloin, and a plate of various desserts including crème brulee. Yum.