HDCP Explained

HDCP Explained: a reader asks…


I have a home theater system and wanted to add an Amazon Firestick to it. I have an available HDMI port on my receiver, and my other video sources work ok (cable box, DVD player). But I can’t get the Firestick to work reliably – I can usually see the video on my TV screen, but can’t hear the audio through my surround sound speakers. I read some of your other articles and am thinking the problem is that pesky HDCP. Can you give me a short explanation of what that is, and how I can go about getting past that roadblock?

Sure! HDCP is short for High Definition Copyright Protection and generally comprises circuitry built into your HD-capable devices for both audio and video. This circuitry aims to prevent digital piracy of protected content, so you can’t record commercial movies, videos and audio to use or distribute freely.

What that means is that your Firestick won’t let protected content (e.g., video or audio) go out to unauthorized devices. Because there are different brands and models involved, the circuitry may not interface perfectly with the different devices (your Firestick, your surround sound system, and your TV). The Firestick may not recognize that your surround sound system is authorized to play the audio. As to why your video shows on the TV screen, it may be that the HDMI for video is passed through the surround sound system to the TV, and your TV is better able to handle HDCP, so the Firestick knows that the TV is authorized.


What usually happens is that when you connect HD equipment and power it on, a ‘handshaking’ process happens where each piece of equipment authorizes itself to the other connected piece of equipment. Some brands and models of HD devices do this only when the device is first powered on, some do it anytime a new device is connected, and some do it every time they are turned on. 

It’s a real mess, and all in the name of stopping piracy. The sad side-effect is that it makes it more difficult for you to use your HD-capable devices without hiccups. So consumers have to try one or more ways to get their devices to play nice together and let them watch HD content. 

One simple way for you to try first is to unplug the Firestick from the HDMI input port on the surround sound system, and also unplug the MicroUSB cable from the side of the Firestick. Wait about 10 seconds or so, then plug the MicroUSB cable back into the Firestick and plug the Firestick back into the HDMI input port. That may initiate the handshaking process, and let you hear and see the HD content from the Firestick.


If that doesn’t work, you may have to power off the surround sound system, and then power it back up. Leave the Firestick plugged in (both to the HDMI and its MicroUSB), and unplug the surround sound system from electrical power. Wait a few seconds, then plug it back in and turn it on. Your surround sound system may re-authorize all attached devices at that point, and then you can watch and hear the HD content from your Firestick.

If everything works ok after one of these methods, you may still not be out of the woods. As you switch from one video source to another, the surround sound system may ‘remember’ the HDCP authorization, or may not. If not, you’ll have to repeat whichever method worked above for you. Annoying as all get-out!

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