Simple Tips how to differentiate a singer sing live or lip sync

Well, with advanced technology and trend right now, especially in Asia (K-pop), most singers often do lip sync. Sometimes the singers do it because of health condition (sore throat, cold, vocal cord nodules, etc) other times it's because the equipment/utility. (The audio sucks!) which is pretty reasonable. But it seems that having a good vocal or singing skill isn't a mandatory for being a singer. With great marketing team, plenty amount of investment, company background/connection, beauty appearance with hardworking attitude, everyone can become a singer in a group.

They don't need to be able to create their own music, write their own lyric, create their own choreography or even choosing their own outfit. This entertainment industry became to commercial and lost the essence about what a 'REAL' singer is. Maybe there is why they are called as idols, or performing dolls. What they need is to perform and dancing the same movement for more than 100x times while being cheerful/cool and handsome/pretty. How about the singing? Well, they can't sing with that kind of choreography without losing breath, so just make them do lip sync..... they just need to looks cool (Maybe that's what their company think).

Looking for business side, there is nothing wrong with it. It's actually work. And it doesn't need a strong vocal to have a good song. But for me, I appreciate a group who can actually sing live and have stage presence to moving the audience. So how do we differentiate a singer who sing live and lip sync. Unfortunately it's hard, you need a good headset to be able to notice the different. But there is several ways to tell if they're singing live or not:

If there is some buzzing/breathing sound comes from the mic. Then again, they might have "LOUD" background music with their vocal to make their singing more pleasant to hear. I don't even joke about this. Most of the time the background music is louder than the actual singing of the idols.
Don't be lied by their MR REMOVED video. You might said that just watch their MR Removed video, I'm sorry to say, most of MR Removed doesn't really give you a real result. Sometimes the idols take several shot before the actual live and combining the best possible one as a live performance. When that happened, you hears some pre-recorded voice, not their actual singing live.
It doesn't mean the idols can not sing. Several of them can, but they choose to play safe. With auto tune and new advanced audio mixer, you can create some "GODLIKE" song with average voice.
Listen to the compliment they got from other entertainer. Every K-pop girl group is very beautiful, but only several compliment as a goddess. They are the one who has more natural beauty or less plastic surgery procedure. Just like that, if you see an idol who get compliment a lot for their singing, it means they can sing WELL. Simple as that.

Well, if you are lucky enough you don't need any video to proof your idols can sing. For example on the video below. SIA (not a Kpop singer, I know) sing it with megaphone without background music.

Some idols who can sing well can improvise their stage, change the lyrics of their song to engage their audience. Some good example is MAMAMOO., Although they still did lip sync or having back ground music sometimes. But they have proven themselves a lot that they are more than capable to sing live while dancing.