Ambilight, Scaling, Subs

Ambilight Ambivalence
A buddy of mine had an older Philips plasma TV with Ambilight. The first time I saw it, I though it was the greatest thing I'd ever seen and decided I had to have a set of my own with Ambilight. However, the Philips sets seem to get pretty mixed reviews on Amazon. The availability and selection also seems to be a little scarce. Are the Philips plasmas and LCDs really to be avoided? And if so, is there an alternative you can suggest?

Doug Muldowney

In my experience, Philips LCDs and plasmas have not been very good in general, so I don't recommend getting a Philips TV at this point.

For those who aren't familiar with it, Ambilight is a Philips-exclusive feature that incorporates fluorescent or LED lights behind the edges of the cabinet. I really hate its "light-show" settings that cause the lights to change color and intensity according to what's on the screen, which I find very distracting.

However, it can also be set to a constant color and intensity, which lets it act as a "bias light" to help alleviate eye fatigue. The proper color for a bias light is technically known as D65 white, and the correct intensity is 10 percent of the TV's peak-white level. You can get a bias light called Ideal-Lume from CinemaQuest for about $60 and simply place it behind any TV.

Scale Me Up, Scale Me Down
My TV is a Panasonic TH-C42HD18 with a native resolution of 1024x768, and we sit about 7-10 feet away from it. We get HDTV from Dish Network and have the option of setting the receiver to output 720p or 1080i. Which setting should I use? Isn't it better to have the TV scale down rather than scale up, or does it not really matter all that much? Also, should I have looked at a 1080p set? I read that at about 7-10 feet, you don't really get the visible benefit of 1080p in a 42-inch display.

Brandon Quintel

My first recommendation is to try it both ways and see which setting looks better to you. At each setting, look at channels that broadcast HD at 1080i, such as CBS and NBC, as well as channels that broadcast at 720p, such as ABC and Fox.

In general, I agree that it's better to scale down than up—removing pixels is easier and less potentially harmful to the image than adding pixels that aren't in the original signal. Also, most HDTV—satellite, cable, and over-the-air—is broadcast at 1080i. If you set the receiver to output 720p, most HDTV images will be scaled twice: once in the receiver from 1080i to 720p (with a deinterlacing step in there as well) and again in the TV to 768p. It's always better to scale the image as few times as possible to avoid the possibility of artifacts. Thus, setting the receiver to 1080i will probably work better most of the time—that is, assuming your TV has a good deinterlacer.

On the other hand, a few channels, such as ABC, Fox, and ESPN, broadcast HD at 720p, so if you set the receiver to output 1080i, you're back to the problem of scaling twice when you watch those channels. Does the Dish receiver have a "native output" option that outputs whatever resolution it gets? If so, try it. In that case, the TV will be doing all the scaling and deinterlacing regardless of whether it gets 1080i, 720p, or 480i.

To address your last point, I always recommend getting a 1080p TV if possible, even if you can't theoretically see any difference in detail between 1080p and 720p at the distance you're sitting from the screen. Even if you can't see the increased detail, you might see artifacts that arise from scaling the picture to fit the native resolution of the screen.

Sub Quandary
I just purchased the Energy Take Classic 5.1 speaker set and a Sony STR-DG820 receiver. I'm using a single male-to-male RCA cable to connect the subout jack on the receiver to one of the two line-in jacks on the sub. Should I bother buying a splitter cable to use both the left and right inputs on the back of the subwoofer? If this isn't necessary, why is there a left and right input on the sub?

Mark Hattrup

Connecting both inputs is definitely not necessary with your setup; just connect the receiver's subout to the left line input on the sub. (The Energy owner's manual specifies the left input, but I'm not so sure it matters.) Some subwoofers, such as yours, have two line inputs so they can be fed from both channels of a stereo preamp, but this is an uncommon configuration. For folks with a surround system, one RCA cable from the sub or LFE output on the receiver or preamp/processor to one of the sub's line-level inputs is the correct way to go.

If you have a home-theater question, please send it to scott.wilkinson@sorc.com.

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