Comcast XFINITY → Re: [Speed] Adding Comcast TV .. Will it slow down HSI?

No, it won't do anything. TV, HSI and Phone are on different channels, they don't effect each other.

You could be on the phone and downloading a file at top speed and the quality of either won't be effected. Same goes with TV.

Good luck and I hope you have a good experience with the TV service.

Adding the TV service could affect the Internet if the cable modem's signal levels previously were marginal- the splitter required for the TV would then put the levels outside of the modem's allowable range.

Thank you!

Also although a splitter may lower the signal they may(if its there) remove a filter that could (depending on its quality) improve your signal after its removed)

if the filter is of low quality (and old) it could be weakening your signal and if its removed your signal might get higher and then the splitter(s) might then drop it back down

so in all I wouldn't worry about it just might want to check the signals before and after the TV switch over

(see if its a safe range away from the limits at both times)