I have found that the quality of sound varies from cable station to station and OTA is the same.
What ever box you use for tv is splitting out the signal coming in over cable, sat or OTA. My digital/analog feeds OTA/cable go through the tv tuner first then out to the receiver. The Denon sees analog for some cable, no definitive signal type for others. The Denon sees 2.0 or 5.1 for OTA.
Charter cable puts out a lot of crappy signal. However they process their feed is the best and mostly worst they can do.
Would a newer tv do better? It is possible. If you have multiple tvs in the house, just listen to the same channel on the different tvs. Some do better than others. But if your getting a crappy signal, there is not much your processor can do.
