Posted Fri Sep 24, 2010 at 12:00 PM PDT by Joshua Zyber
Editor's Note: Each Friday, High-Def Digest's own HD Advisor will answer a new round of questions from our readers. If you have home theater questions you need answered, send an email to [email protected].
Answers by Joshua Zyber
Q: I have a powered subwoofer for my home theater system. On my old A/V receiver, the subwoofer power cord plugged directly into the unit. When the receiver turned off, so did the subwoofer. I recently got a new receiver that does not have a power outlet on it for the subwoofer, so I have to plug it directly into the wall. I was wondering if the subwoofer can become worn out if it is always plugged into the wall? Should I unplug it when I'm not using it? I should also mention that the subwoofer does not have a power switch on it.
A: I'm pretty sure that all of the powered subwoofers I've ever used have offered a Standby mode that will automatically turn the subwoofer off if it doesn't receive a signal for a certain amount of time. On mine, there's a power indicator light that turns green when active or red when not in use. You haven't mentioned the brand or model of your subwoofer. I would check the unit to see if it has a Standby switch. If not, Google the model number to see if you can determine whether it defaults to a Standby mode.
If your powered subwoofer does not have a Standby mode, I'd suggest that plugging it into a power strip that can easily be turned on or off would be a better solution than constantly plugging and unplugging it. I connect all of my home theater equipment to a power strip and turn it all off when not being used.
In fact, a power strip with surge protector is a good idea in general, to protect your expensive HT gear from potentially damaging power surges.
Laserdisc Viewing in the HD Era
Q:I was wondering whether there is any benefit to be had in running the Composite video from my Pioneer CLD-99 Laserdisc player through a modern A/V receiver that has upconversion / upscaling capability? I have played some of my Laserdiscs through a friend's 32" LCD and the video quality is atrocious, especially when zooming a letterboxed Laserdisc movie to fill the screen. Digital sources on the same screen look great, obviously. By upscaling analogue Laserdisc to 1080p and sending to a compatible HD monitor via HDMI, would there be any improvement in picture quality? Or am I stuck with viewing Laserdiscs on my old CRT to get the best picture from analog video sources? I recall there being line-doublers that high-end laserphiles used to improve picture quality back in the pre-DVD era. Is this similar to what upscaling A/V amps do today?
A: Back in 2004, I wrote an article on this subject for my own Laserdisc site. While that article is a bit out of date with regard to the latest video processing technology available in modern TVs and A/V receivers, the basics still apply.
Laserdisc video is (like DVD) an interlaced standard definition signal. To view this on an HDTV, the picture must be deinterlaced and then scaled to the set's native resolution. Every HDTV has a processing chip built in that will perform this deinterlacing and scaling to all video signals it receives. Not all processing chips are created equally, unfortunately. So you may get better results pushing these functions to an A/V receiver or an external video processing unit instead, if either has a better chip installed.
Old-fashioned "line doublers" were simply an early form of video processor that would deinterlace a 480i signal to 480p for display on CRT projectors. The technology is quite primitive by current standards. A line doubler that cost $10,000 - $15,000 back in the day can be easily bested by the processing chips that come standard in most $100 DVD players today.
Even with the best deinterlacing and scaling, you'll simply need to keep your expectations in check for how good a Laserdisc picture can be made to look on an HDTV. The format is quite low resolution compared to what we have now, and its Composite video encoding is hampered by its antiquated design. Also, digital televisions are not optimized for playback of analog signals. Limitations in the raster of older CRT televisions would help to mask some of the flaws in noisy analog video signals. Digital televisions are more transparent, which is a benefit to a high-resolution digital signal, but can be harmful to sources like Laserdisc.
I still have a sizable Laserdisc collection. I continue to cherish those discs for the years of enjoyment they brought me back when crapvision VHS was the only other alternative for watching movies at home. However, truth be told, I have a hard time watching Laserdiscs today. There are steps that can be taken to improve an LD picture on an HDTV, but there will always be inherent weaknesses in the picture quality that you won't be able to get past.
The HD Advisor knows many things, but he doesn't know everything. Some questions are best answered with a consensus of opinions from our readers. If you can help to answer the following question, please post your response in our forum thread linked at the end of this article. Your advice and opinions matter too!
Multi-Region Blu-ray Drives for Computer
Q: I've been thinking about upgrading my computer and was considering adding a Blu-ray drive which I could then connect to my TV. Are these multi-region like DVD drives?
Check back soon for another round of answers. Keep those questions coming.
Joshua Zyber's opinions are his own and do not necessarily reflect those of this site, its owners or employees.
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