johned,
There has been a lot of good advice given so far, but I just wanted to make a point that I had not seen made yet(maybe I missed it somewhere).
When your coax cable inputs to your STB, the RF carriers have to be decoded(for all services) and decrypted(for most services). This is the first act of "video processing" that is necessary, in regards to your STB/TV setup. Running coax from your STB to your TV means that your STB must then perform another round of "video processing" to take the newly decoded video & re-modulate it back to an RF carrier. Your TV then must decode this RF carrier and display it, thus giving you one last round of "video processing".
The alternative to this, is to use HDMI or Component outputs from the STB. You still have to decode/decrypt the first time with the STB...but you are leaving the video in a native digital video state. Thus when you transfer the video from the STB to the TV, many times it appears "better". The difference between HDMI & Component, in general, is negligible in most situations, and really comes down to a cleaner install...i.e. 5 wires vs. 1.
In the latter install, you are just not degrading the video "as much" as you are when you re-modulate & decode again(like the first install). Sometimes the difference in quality isn't very noticeable, or even at all. This is because some STB's perform this function(decode/re-modulate) better than others...and some TV's decode RF better than others. As far as the HDMI vs. Component quality, the TV will (eventually) use the video components to display the image...this again comes down to which 'box' can transfer the video to a display better? STB or TV? Usually your money's on the TV, but it's generally not noticeable, and will vary from STB to STB and TV to TV.
The biggest thing to keep in mind, as with everything in CATV, DTH, etc, is that we can't technically "improve" the video we get from providers...we can only "not screw it up better". Hope that helps a little.
This is CABL.com posting #210706. Tiny Link: cabl.co/m2YE
