Cramming surround sound into an LCD TV is tricky. TV makers have tried but, to protect the screen, have ended up with bulky, subwoofer-less sets. Bass causes shaking that can blur images and damage pixels over time, and more speakers generally means broader frames. Now Bose has designed a 16-speaker setup for its HDTV that disperses audio from what looks like no more than a 46- inch LCD. Here’s how a subwoofer and room-filling virtual surround sound disappear into a case only a couple of inches thicker than other LCD TVs.
Drivers: Six 2.5-inch woofers push more than three times the air of others of the same size. They’re arranged in two rows, pushing in opposing directions, so that any shaking they cause is kept away from the vulnerable screen. The result is bass that shakes the floor, not the LCD.
Bell: Engineers analyzed the TV to determine where it was least susceptible to LCD- damaging vibration and mounted the bass enclosure to those spots. Bass funnels through this horn, called the Waveguide, which directs the sound out the bottom of the set.
The “Surround” Speakers
Fronts: Midrange sounds, especially dialogue, come from seven speakers mounted in a cluster near the top of the set. Together they steer location-specific sounds, such as a distant gunshot or someone yelling from off-screen, around the room.
Rears: Two one-inch-thick speakers in the top corners handle background sounds such as traffic and wind. A transducer sends timed sound waves that escape out tiny holes on the top and rear edges and bounce off the back and side walls of the room.
Tweeter: While the virtual front and rear speakers handle most central midrange sounds, center-channel high frequencies, such as chirping birds or violin soundtracks, fall mainly to a single tweeter located at the bottom of the set that sends sound straight out.