Back to basics: The AV Receiver
You have heard the term AV Receiver. You may have heard it from your kids. Maybe you heard it around the water cooler or coffee pot at work. Maybe you just picked the term out of an overheard conversation at Starbucks. Regardless of where you heard about an AV Receiver, you have questions. What exactly is it? What does it do? Why would you want one? We have answers, read on.
What is an AV Receiver?
An AV Receiver (AVR) is an electronic device into which you plug all of your audio-visual components. The “AV” in AV Receiver is short for Audio Visual. You plug your TV, cable box, Blu-ray player, CD changer, Digital Audio Player (DAT), etc. into your AV receiver – it “receives” all of the electronic signals from the connected components. You also connect your surround sound speakers to the AVR (We’ll get to the speakers shortly). Basically, an AVR serves as a hub for the electronics in your entertainment system.
At this point, you may be asking yourself; why can’t I just plug everything into my TV? If you only have a few connected components, you may be able to do just that. You will not, however, get the best performance out of your electronics or be able to fully enjoy all of the effects that are broadcast or come standard with today’s electronic media. Finally, you will not be able to enjoy surround sound like what you hear at a commercial movie theater.
How does an AV Receiver work?
The simplest description of what an AVR does is, it takes the audio and video signals from each of your various electronic devices and divides them up by video or audio signals. The video signals are sent to the TV screen and the audio signals are sent to the speakers connected to the AVR. Pretty straight forward, right? If that is the extent of what an AVR does, it isn’t particularly revolutionary. Fortunately, there is quite a bit more.
To process the sound signals, the AVR first receives the digital signal from the source (cable box, Blu-ray player, DAT, Bluetooth, etc.), then decodes the format in which the signal was originally recorded. Most AVR’s can decode Dolby, DTS, THX, and several other formats. This coding tells the AVR which sound to send to each of the connected speakers and how to send the sound to the speakers. Dividing the sound signals up into different channels is how an AVR produces the two (or three) dimensional sound stage that helps make the soundtracks of movies so rich. For dialog, the primary speaker is the center channel. Sounds that originate to the right of the viewer are produced primarily by the right-front speaker, and or by right surround speaker(s). Sounds that should come from behind the viewer are sent to the rear speakers. The Deep bass notes are split off and sent to the sub-woofer(s). You get the idea.
In addition to sending sounds to different speakers the AVR interprets the type of sound to send. For example, because dialog tends to be a point source, the primary speaker used when someone is speaking on screen is usually the center speaker. If a character is speaking in an environment that produces echoes, like an empty room in a house, the AVR might send secondary echoes to the surround speakers. The AVR can also enhance those effects by using different sound “scenes.” By choosing a “stadium” setting on the AVR while watching a football game, the crowd noise and cheering is enhanced. This creates a more immersive experience for watching the game.
There are concert settings for watching live music performances, quiet or night modes for minimizing effects like bass when watching programs when you don’t want to disturb others. Other settings can enhance or minimize the surround effects. There is even a “flat” setting that doesn’t do much of anything to the sound. By experimenting with the settings as you use your AVR, you will find which sound effects you like and which ones you don’t.
By calibrating your AVR to the room and speakers, you get a custom sound stage that more accurately reproduces the sounds as they were meant to be heard.
Equalizing isn’t always about being equal
Pretty much every new AVR has some sort of built-in calibration software. Yamaha uses a program it calls YPAO (Yamaha Parametric Room Acoustic Optimizer), Denon and a few other manufacturers use a program called Audyssey, Pioneer uses MCACC (Multi-Channel ACoustic Calibration System), etc. There are as many acronyms as there are manufacturers. What you need to know is; the program that comes with your AVR, simply calibrates the speakers you have to the room in which they are located.
All of the calibration systems work by using a microphone that is temporarily connected to the AVR. The program sends test tones and sounds to each of the connected speakers and the sub-woofer. The program then ‘hears’ the test tones with the microphone and notes minute differences in the tones that emanate from each speaker. In addition to listening for difference in the sound levels of the different speakers, some programs also compare the sound curve of each speaker against a built-in template. Finally the program adjusts the audio sound curve and volume for each speaker to optimize the sound levels at the microphone location.
By calibrating your AVR to the room and speakers, you get a custom sound stage that more accurately reproduces the sounds as they were meant to be heard. These calibration programs get the sound very close to optimal. By using some of the other adjustments in the AVR the sound can be finely tuned to the owners taste. For example, I personally like a little more bass in my movies. The AVR does this with a simple tweak of the bass setting in the equalizer section of the settings.
One last thing to keep in mind with AVR’s. Just because you have one of the new 4K flat screen TV’s, it doesn’t mean that you can automatically watch 4K content on it. If that 4K content is going through an AVR, it is important that your AVR has an HDCP 2.2 label on the HDMI inputs. HDCP is short for High-bandwidth Digital Content Protection. What you need to know is that a 4K signal must be connected to, and from, HDCP 2.2 terminals at every step along the way. If you don’t have HDCP 2.2 inputs at any point along the path the signal takes, you don’t get a picture. Almost all higher-end AVR’s have at least one HDCP 2.2 terminal. Many have several. If the AVR has at least one HDCP 2.2 input, the output to the TV will automatically be HDCP 2.2. All quality HDMI Cables are more than capable of transmitting the higher band-with signals. The HDCP 2.2 designation is for the terminals and software of the components themselves.
The number of HDCP 2.2 terminals you need on your AVR is determined by the number of 4K sources you have. If you don’t have a 4K cable service, you probably don’t need a HDCP 2.2 terminal for that source. If you have a 4K Blu-ray player, you need to have it connected to a HDCP 2.2 HDMI input on the back of the AVR, etc. As more content becomes available in 4K format, you will likely want more HDCP 2.2 inputs to pass the higher quality 4K signals through. That is why you want to get an AVR that has as many HDCP 2.2 inputs as you can practically afford. HDCP 2.2 inputs are more costly than HDMI inputs without the designation. This translates into AVR’s with more HDCP 2.2 terminals typically costing more.
Other Features an AV Receiver Might Have
The ability to take in signals from a source (cable box, Blu-ray player, etc.), translate them, and send them out to your TV and the appropriate speakers is only the start of the capabilities of today’s AV Receivers. More features are often included in new AV Receivers with new feature ideas are being thought up constantly. For example, you might find features such as:
- Connecting to your home network so the AVR can connect to internet music sources
- Sending sound and video to multiple rooms
- Sending sound to speakers throughout your home
- Connecting to your mobile device with Bluetooth
- Responding to your voice commands using Alexa
Other features not mentioned here are possible. When shopping for a receiver, be sure to check out all the details. Think about your future: is it possible you might one day have a party and want the same music playing throughout your home? Is it possible you might want to use your AVR to handle connections to internet music sources (TuneIn, Spotify, SiriusXM, etc.)? Are there other must-have’s and nice-to-have’s on your list?
We hope this has helped you understand what that magic box full of electronics does, and why you might want to have one in your home entertainment system. If you don’t currently have an AVR, we hope that you have a better idea of what to look for and why. Finally, we hope you enjoy your home entertainment system each and every day!
About Brian Hill
Brian Hill is a home theater enthusiast who has an extensive background in sales. His interests include music & movies, F1 & NASCAR auto racing, hot rods (he has a '56 Nomad) and hockey — Go Sharks!
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