Hey dear Zakreconyyy! The Sony SRS-XB31 is the predecessor of the Sony SRS-XB30 which is larger/more expansive than the Sony SRS-XB20/SRS-XB21. Here you can compare between them: www.bhphotovideo.com/c/compare/Sony_SRS-XB31_Portable_Wireless_Bluetooth_Speaker_Black_vs_Sony_SRS-XB21_Portable_Wireless_Bluetooth_Speaker_Black_vs_Sony_SRS-XB20_Bluetooth_Speaker_Black/BHitems/1396861-REG_1396857-REG_1319169-REG Best regards, OVR Guy I invite you to: - Subscribe "Original Video Reviews" RU-vid channel - goo.gl/6ZYATi - Subscribe "OVR Fashion" RU-vid channel - goo.gl/wk0IPH - Subscribe "OVR Kids" RU-vid channel - goo.gl/tmaAfj - Subscribe “OVR Chef” RU-vid channel - goo.gl/UxVSdn - Subscribe "OVR Travel" RU-vid channel - goo.gl/UBDtb8 - Like my Facebook Page - goo.gl/ndUWsq - Follow my Twitter account - goo.gl/0LdOHl - Follow my Instagram account - goo.gl/FlaC9f - Visit my Amazon (US) influencer page to get the items I review - goo.gl/yjbW19 - Follow my Aliexpress profile - goo.gl/H7McYw - Follow my website - www.originalvideoreviews.com