I have a new smart TV and a new amplifier, a Yamaha, back panel seen here (back panel on right):
And as you would expect, the smart TV has all the latest HDMI slots, etc. Currently I have cable coming into a set top box and straight to the TV. I want to add speakers (unpowered) such that I can hear the TV, Netflix/Hulu/etc, and a DVD player , ideally so that they as well as the TV speakers can be heard. How do I do it?
Not sure what you mean by “unpowered speakers.” You can plug speakers into the back of the RX-V381, into the panel labeled SPEAKERS. 5.1 channels, > 100W per channel according to their ad. Don’t forget to route from the TV box to the amplifier using HDMI or whatever it has.
I briefly searched online and it suggested using speakers that you plug into an outlet. Thanks for the other info.
Connect the HDMI ARC (audio return channel) ports between your TV and receiver with any sort of HDMI cable. Connect speakers to receiver. Done.
Whether your TV speakers also play at the same time is usually a TV setting. Check the menus.
This is what I’ve done: first, the original setup was cable signal to set top box, and out from there to HDMI 3. All good. Now, I’ve used the HDMI ARC from my TV back to the receiver as suggested, and into the HDMI 3 input on reciever. Speakers connected as usual. But no sound, so then I switched one speaker to surround sound, and now still I only get sound from TV speakers.
I have HDMI Arc on Tv and receiver. But this is what I don’t get. On receiver, HDMI ARC says “output”. So what do I select on the receiver to hear?
ARC is the technology that transfers sound back and forth from the TV and the receiver over the HDMI cable. One would think that this would be enabled as default, but I found out that it was not on my setup. If I recall correctly, I had to enable ARC both on my TV settings and my receiver. I suggest diving deep into the menu settings of both and seeing if ARC is enabled on both devices.
You should select the source of the AV signal you want to watch, in your case HDMI 3.
Yes, first of all, make sure the speakers are correctly connected to the receiver. If you are only using left and right speakers they should be connected to the banana terminals, not the surround sound section.
ARC needs to be enabled via the Yamaha’s Setup menu, and perhaps on the TV set as well. You also have analog and digital audio input jacks on the receiver as a fallback option.
Thanks, everyone. If I told you I’m calling Task Rabbit, would that indicate how successful I was? 
Before you do that, consider the fallback plan: does your TV have a digital audio output? Probably an optical connection or perhaps a coaxial connection on older sets. If so, you can connect the set top box back into the TV, and then connect the digital audio output to the receiver (audio 1 or audio 2 on the lower left side on the back of your receiver). Doing it this way means that the receiver is only handling the sound, you will not need to connect an HDMI cable to the receiver at all. Your set up is simple enough that this will work just fine.
Okay, I’ll look into that. Thanks for your help.