| Video Noise February 2001
Most Everything You Need to Know about Digital
Cable TV
The area where I live happens to be served by Time Warner
Cable. The same people who brought us Road Runner cable modems (which offered no
way to connect directly to your email box away from home) have now brought us digital
cable, "with up to 250 channels and 40 channels of commercial-free, CD-quality
music." So what exactly does this mean?
First of all, there is some clever marketing going on here.
What you should be aware of is that channels 1-99 are the same analog signals you have
been receiving for years. All the analog cable channels are still analog even though you
pay extra for digital cable. So your local channels, including PBS, will continue to look
just like they always have. When I asked a spokesperson for Time Warner Cable whether or
not the analog channels would ever become digital channels, I was told that there were no
plans to do so at this time.
Well, at least the analog cable channels aren’t
worse than they were before, or are they?
Let’s see, before getting digital cable I could
connect the cable directly to my TV and use the TV’s tuner. With digital television,
I have to use the tuner in the Scientific Atlanta digital-cable set-top box. And the
winner is . . . oh, bloody heck, the tuner in the TV gives a better picture and it changes
channels instantly. The lovely digital-cable box, on the other hand, has an annoying delay
when changing channels, even the analog ones.
So just what channels are digital when you get digital
cable?
In our area, digital channels start at 100. The actual
digital channels you receive will vary from cable system to cable system. We get such
worthwhile selections as Bloomberg Overnight TV, Style TV (for fashion
lovers), a slew of cable news and sports channels, four additional Discovery Channels,
Disney Toon, BBC America (which allows you to see the shows you aren’t interested in
watching on PBS a year or two earlier than they appear on PBS), one channel of Encore, and
the only winner in the pack, Speedvision (all manner of powered vehicles -- boats, cars,
airplanes and motorcycles, including live Formula-1 racing). Then there are the digital
pay services: multiple channels of HBO, Showtime, Cinemax, Encore and assorted adult
channels. There are also about 30 pay-per-view channels at $3.95 per movie, and you
can’t catch the movie again later if you get interrupted; you get one shot at it.
And the quality…
Image quality of the digital cable channels is really quite
poor compared to DVD. In fact, it is often worse than the prototype DVD demonstrations
that I saw before DVD was released to the public. Those were loaded with a variety of
compression artifacts with some type of problem visible in nearly every scene. On the
other hand, digital cable has none of the analog artifacts you are used to seeing on
typical analog cable channels, like noise (graininess), color bleeding and ghosting
primarily.
There is an (incorrectly named) "AC-3" digital
coax outlet on the digital set-top box, but it rarely has anything coming out of it. So
far there has been no 5.1 sound ever on HBO, but it appears to be active for some, but not
all, pay-per-view movies. So we are reduced to ProLogic decoding of almost
everything we watch on any digital-cable channel. Never mind the fact that most of the
free digital-cable channels appear to be mono or newsroom stereo.
Video outputs from the set-top box are composite and
S-Video, though there doesn’t seem to be a large difference in image quality between
them. Digital cable works a lot like digital broadcast TV, you either have enough signal
to have a picture and sound or you have nothing. I added splitters to the line repeatedly
until the digital channels stopped working -- remove just one splitter and all the digital
channels come right back with no evidence that they are marginal for signal strength.
I’m not sure if this is a good thing or a bad thing. If the last "cable
guy" who was here hadn’t been so interested in all the home theater and audio
equipment I have setup, I might never have gotten the signal boost that I needed to have a
strong enough signal to weather the four-way passive splitter that carries the CATV signal
to various locations in the house. Without his 10dB boost at the street, I would have had
a dead digital set-top box in the main theater/listening room.
Time Warner Cable’s misleading digital-cable
advertising never actually says all the channels are digital, but they sure don’t
give you a word of explanation up front either. I never even thought to ask if all the
channels were digital; I assumed they all would be. Wouldn’t you?
As for the "40 digital channels of CD-quality
music," there are 40 of them and, yes they are digital, but they are far from CD
quality. They are not even remotely similar to CD quality. They are more like middling MP3
quality. The sound is not very transparent; it lacks bass, lacks highs, and just generally
has no impressive qualities. There is a pretty decent selection of stations playing a wide
variety of music, but it is more akin to AM radio sound (less the static and odd noises)
than even FM radio, let alone CD quality. You can see the song being currently played on
your TV as long as Time Warner Cable’s text server hasn’t choked, which
it does occasionally.
Digital cable doesn’t cost all that much in our area.
It’s about $12 per month more than the level of analog service we were getting
before. The extra fee includes an additional ten or so, free digital-cable channels, the
set-top box, and the remote control for the set-top box. For $11.20 you get five channels
of HBO. The incremental cost of digital cable isn’t large, so I guess you get what
you pay for -- not all that much. If this is all Time Warner Cable has in their hip
pocket to fight losses to the second major digital satellite service in the US, they are
in trouble, because their digital-cable service, so far, is outclassed by a large margin
by the digital-satellite services.
The only considerations keeping me from digital satellite
are:
- Local channels do not integrate well and they are not
offered as a digital service, so we would have to maintain an outdoor TV antenna.
- Three of the 18" to 24" antennas would be required
to drive the five or six set-top boxes needed to service all the TVs in our house,
including guest rooms, which get only occasional use. The satellite companies charge $5
per month for additional set-top boxes. That would add at least $20 per month to our
digital-satellite bill. The extra set-top boxes aren’t dirt-cheap either. They could
easily add another $500 to $1500 in installation charges.
- We’d lose the $5 per month Road Runner credit we get
for having Time Warner Cable service. I’m 100% addicted to cable modem speed.
Disconnecting cable TV and going 100% satellite would cost me another $5 on my Road Runner
bill.
If you are avoiding satellite for the same reasons I am,
look before you leap into digital cable. At least now you know the questions to ask to
find out if your local digital cable is as limited as what I’m experiencing here.
...Doug Blackburn
db@hometheatersound.com |
