The best replacement for 5.1 is 7.1.

The best alternatives to 5.1 are rated as following:
★★★★★  7.1
★★★★  2.1
★★★  dts
★★  7.2
★★  stereo
★★  6.1
★★  7.1 surround sound
★  sound bar
★  5.2
★  7.1 surround
★  7.1 receiver
★  7.1 headset
★  soundbar
★  dolby surround
★  2.1 speakers
  3.1
  7.1 sound
  7.1 headphones
  5.2 surround
  7.1 gaming headset
  7.1 home theater
  dts 5.1
  2.1 surround sound
  wma pro
  ac3 5.1
  2.0
  2 channel
  2.1 sound bar
  5.5
  7.1 which is better
  4.1
  5.2 surround sound
  7.1 channel
  5.01
  5.5 vmware
  7.1 speakers
  7.2 surround
  2.1 computer speakers
  7.1 audio
  dolby digital 5.1
  2.1 soundbar
  2.1 home theater
  2.1 audio

Your alternative for 5.1 is not listed? Suggest!
Speaking about 5.1, one probably shouldn't forget about vlc.

Other search terms related to 5.1 and their ratings are:
★★★★★ vlc
★★ shsh
★ divx
You have in mind a companion for 5.1 and it is not yet here? Propose!



Google Trends

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5.1
7.1
2.1