Q&A - February/March, 2007

LCoS Limitations?

Q. I've been considering a Sony KDS-60A2000 LCoS rear projector. But the salesman at my local A/V shop advised me that LCoS, like LCD technology, suffers from motion blur, thus making it unsuitable for viewing some sports and playing videogames. He said DLPs were "quicker" and better suited for that purpose. Was he correct? Also, can I place unshielded tower speakers within 8 inches of an LCoS display without any ill effects? Victor Rigoli Red Hook, NY

A. Al Griffin says: LCoS is related to LCD in that both technologies rely on cells packed with liquid-crystal material to generate images (the liquid crystals twist and untwist in response to electric current to pass or block light). Even so, the motion-blur artifacts associated with flat-panel LCD TVs generally aren't a problem with LCoS. Sony's rear-projection SXRD (Sony's variant of LCoS technology) sets, for example, are spec'd for a 2.5-millisecond response time - a considerably faster rate than most flat-panel LCDs can muster. And Sound & Vision's recent tests of Sony's KDS-60A2000 and other LCoS-based RPTVs uncovered no issues with motion blur, which, as your salesguy said, isn't a problem with DLP sets. Also, since unshielded speakers create problems only with CRT-based TVs, you shouldn't worry about placing your unshielded tower speakers close to an LCoS model.

Power Plays

Q. We live in an area subject to occasional power outages, so we have all our equipment running through a surge suppressor with an on/off switch. After we've turned off all the equipment, we then turn this switch off. Are we causing any problems to the equipment by following this method? If we left the power switches to the individual components on, and then turned off the surge suppressor switch, would that cause problems? S. Fussell Cottage Grove, OR

A. Ian G. Masters says: The order in which you turn off your equipment is unimportant, and with the exception of projection displays, whose fans typically run for a while after you've powered down, whether you do it all at once with the switch on the power strip or component by component makes no difference. Turning the system on can be a different matter, however. Some components tend to inject a definite spike into the circuit when they're powered up, and if the amplifier section (whether separate or part of a receiver) is active, it can send a potentially damaging pulse to your speakers. If that's a problem, you would be well-advised to make sure you turn the amp on last, which means that it's a good idea to turn at least that component off separately when shutting down your system.

X