How to read an AVR's spec sheet.
Every electronic device or component we get has a Specifications (Spec) Sheet that comes along with the manual. A Spec Sheet is meant to give you a detailed overview of the product with all the specific technical information and know-how. These Spec Sheets for some devices can be quite intimidating at first sight with technical jargon and symbols that we may have not been exposed to. AV Receivers have some of the longest Spec Sheets when it comes to consumer electronics which serves as a testament to the number of roles/duties they perform. Here is a breakdown of all the most common Specs that would be featured.
Number of Channels
When looking at getting an AVR, one of the first things that one would notice is a set of numbers, 5.1, 7.1, 7.2, etc. These numbers are to denote the number of separate audio channels that the AVR supports. We can break this set of numbers down further. Consider 7.2, the first number being 7, denotes that the AVR supports 7 powered audio channels. This could be the Left, Centre, Right, Left Surround, Right Surround, Left Rear and Right Rear. The Left Rear and Right Rear channels can be rerouted to either support Atmos channels or to bi-amp the front Left and Right channels. The 2(in the 7.2) denotes the number of separate subwoofer channels that the AVR would support.
Probably the most important technical specification of an AVR would be the power output. Power Output is usually denoted by a group of terms like 95W(8 ohm, 20 Hz - 20 kHz, 0.08%). This would mean that each powered audio channel that is supported by the AVR will receive an audio signal with a power of 95W at an impedance of 8 ohms between 20Hz and 20kHz with a Total Harmonic Distortion(THD) of 0.08%. The 8 ohm impedance mentioned is to match impedances with the speakers that would be connected to the AVR. Do note that when we match a 6 ohm speaker to an 8 ohm output, the power output of the AVR would increase.
Every AVR supports certain audio formats that are standardised world wide. Some of them being MP3, WMA, WAV, FLAC, Dolby Digital, DTS, Auro 3D, Dolby Atmos, etc. These audio formats denote the audio processing that the AVR supports. Formats such as MP3, WMA, WAV, and FLAC are stereo sound processing formats while formats such as Dolby Digital, DTS, Auro 3D and Dolby Atmos are surround sound processing formats. Each surround format processes the surround audio channels differently and hence lead to different audio experiences. Dolby Atmos is the most frequently adapted audio format that is supported by most AVRs today.
All AVRs will need to support video processing as they are usually the source of media for the television or projector. Some Video Formats that are frequently seen are Full HD, 4K and now even 8K. We would also see a certain frame rate with this format as well. These formats denote picture resolution that the AVR supports and at what frame rate. Some of the newer AVRs support 8K resolution at 60 frames per second which is usually denoted as (8K at 60Hz or 8K at 60fps).
Inputs & Outputs
Every AVR has a number of input and output ports that it supports. Every input and output has its own purpose and supports different forms of data transmission. Most AVRs are based on HDMI connections and hence will have multiple HDMI inputs and outputs. Some AVRs also support Optical/TOSLINK connections. All of these inputs and outputs are to ensure that AVR is the hub of all the entertainment in thee home or living room. Most recent AVRs also support Bluetooth and WiFi connectivity with some going even further to support Voice Assistants, Spotify Connect and even Apple Airplay and Airplay 2.
Some AVRs have an added feature of being able to support multiple zones of audio. This would mean that some speakers can be placed in other rooms to form another audio zone. These separate zones would be controlled independently or together depending on each AVR and its processing capabilities. Most AVRs that support 7 powered audio channels or more do support multi-zone audio.
Power Consumption Ratings
These values usually denote the amount of power that the AVR would consume or require to function at various modes. When the AVR is On and working, the power consumption would be at its highest while the power consumption would be the least when the AVR is Off. Some manufacturers do give a Power Consumption Rating for when the AVR is even in Standby.