Up until now, even though our Cisco IPN4320-SG-A DVR receiver is HD-capable, we've not yet subscribed to HD programming. That being the case, I've had our HD-ready TV connected to the receiver via component video cable with composite (red/white) audio. Having just found out, though, that AT&T is currently offering a free month of HD programming, I was thinking of changing that connection type to strictly HDMI (via a single HDMI cable for video and audio) so we can get full HD during the HD trial period.
I was wondering, though: if we decide to not permanently switch to HD programming, can I simply leave the TV hooked up to the receive via only the single HDMI cable and still be able to view SD audio/video, or will I need to switch the cabling back to how it was previously (component/composite)? Would it actually be OK to leave all that cabling in place (single HDMI cable, component for video, and composite - red/white - for audio) permanently, that way we're covered whether we get SD or HD programming in the future, or will the receiver and/or TV get "confused" about which signal to use?
FYI: I chatted online with an AT&T rep. yesterday and he said that SD programming (video and audio) would display just fine on our TV if it were connected to the aforementioned receiver only via HDMI cable. Even though I double-checked and he gave the same answer, I'm still not 100% sure I trust his answer.
And so you'll know, the reason I'm not (yet) simply trying these connection options out myself is because I'm trying to figure out what cables to buy - trying to avoid buying anything I don't need to use - and I want to make sure the optimal (and simplest) setup is put in place the first time around. Please know: I don't care what it takes cabling/cost-wise, I just want the best video/audio quality possible.
Sincere thank you in advance for any responses/assistance!