Home theater receivers are a required part of your home theater setup, if you want the ultimate immersive experience when listening to music and watching movies. But if you’re looking to buy a new AV receiver, you’ll have to understand a little bit more about the difference in technology between them to make a truly informed decision.
Which is Better: 5.1, 7.1 or 9.1 surround sound?
Both 5.1 and 7.1 channel home theater receivers have advantages and disadvantages. However, it depends on the setup you already have or want to implement—the source components you’re using, for instance, or how many speakers you want to use.
The standard for the last twenty years has been 5.1 channel AV receivers. In small or average-sized room, 5.1 is completely fine. The Center channel serves as the anchor for more treble distinctions like dialog and vocals in music. The Left and Right Front channels are for the main sound info or stereo music replication. Left and Right surround channels serve to make motion effects from movie soundtracks and ambient sounds sound better. Finally, the subwoofer opens up for extremely low frequency effects for the full surround sound effect.
In comparison, 7.1 channel home theater receiver has more channels, but splits surround and rear channel information into four channels. This means, ambient and side sound effects are directed to the left and right surround channels. The 7.1 setup adds more depth and precision to the surround sound experience. Adding upon the 7.1 channel home theater receiver setup, 9.1 uses even more speakers.
However, all types of setups are excellent investments. A few things to consider with 9.1 or even a 11.1 channel receiver is, unless your receiver is Dolby Atmos or DTS:X-enabled and your speaker setup with both horizontal and vertically mapped channels and playing Dolby Atmos/DTS:X encoded content, the receiver is actually post-processing the original 5.1, 6.1, or 7.1 channel encoded soundtracks, but places them in a 9 or 11 channel/speaker environment. Suffice it to say, the sound experience will be impressive to any ear.
The reality with this audio technology lies within the content that is currently produced. The majority of any surround sound audio, including DVD and Blu-ray discs, is mixed for 5.1 channel playback. So, a 5.1 or 7.1 channel home theater setup will provide an easy solution.Source: https://www.lifewire.com/5-1-vs-7-1-home-theater-receivers-1846774