For years, we've seen attempts to disguise loudspeakers as paintings. A pair of announcements last week highlights the ongoing drive within the consumer electronics industry to find new ways to hide speakers within other objects.NEC is introducing what it is calling the world's first personal computer equipped with an LCD monitor that also functions as a speaker. The company says it will start shipping the new machine for the Japanese market starting this week.The new laptop comes with a 17"-wide LCD screen that delivers video and also generates sounds, "creating a theatrical atmosphere by spatially integrating the image and sound." NEC says the LCD screen was developed by Authentic, a subsidiary of NEC, based on SoundVu technology which the company licensed from NXT.
The company says that the screen speaker system incorporates a subwoofer and is made of an acrylic panel that also suppresses the reflection of light. The sound is created through the vibration of the acrylic panel, or "vibration board," which replaces the LCD screen's normal protection surface. According to NEC, "Two exciters attached to the right and left sides of the speaker make the acrylic panel vibrate."Another approach is being developed at SRI International. Engineers there have created speakers made of a thin sheet of silicone or acrylic copolymer coated on both sides with "electrodes" and stretched over a frame. When an electric signal is sent across the sheet, researchers report, the electrodes cause the silicone to contract or expand and create sound waves.SRI emphasizes that the materials used can be made transparent and that their tests indicate "such loudspeakers have demonstrated good sound pressure output and good fidelity at frequencies from 1.5kHz–20kHz." However, SRI says that the speakers require augmentation in the lower frequencies as well as custom low-current, high-voltage amplifiers. SRI's Roy Kornbluth says, "It will require another year or two of acoustic fine-tuning before SRI's speakers can match today's high-fidelity speakers."
