if cable box is HD do all my tvs have to be HD

[Terrie_5]

If comcast cable box is HD, do all the other TVS connected to Digital Adapters have to be HD.

 

[greens]

Can't 100% tell what you're asking, but if you convert from HDMI to RCA or composite you could encounter problems. HDCP won't work with adapters, and some streaming services require HDCP to function.

For example i know for a fact a ROKU won't work with an HDMI to RCA adapter. But i can't say for certain regarding your cable box.

 

[americanaudiophile]

No they don't.
The digital adapters take care of each TV separately.

 

[jsmithepa]

Each TV must have its own set-top box (service provider backroom calls it additional revenue stream).

 

[greens]

These cokments having nothing to do with going from an HD TV to an old TV.

Old TVs do not have HDCP and will not work with HDCP digital content.

There is a handshake involved. The cable box asks the HDCP TV "are you a recording device". The TV says "no, I'm a TV" and he broadcast plays.

Using an adapter to convert from digital to analog signals will mean that when the cable box asks "are you a recording device?" The adapter and old TV can't answer the question because they are not HDCP, and the broadcast is halted.