Why my soundbar have lag or sync issue when connected to a mic mixer or Popsical Remix II?

Not all soundbars are designed for karaoke. Some have speakers too small which will cause distortion when singing, while some others might be ok. It is still recommended to ask your speaker's manufacturer whether your soundbar is suitable for singing. 

Besides distortion, another annoying issue is lag or sync issue either from the mic or the song source. While sometimes, you might get lucky if there are any delay settings in your TV side to resolve this issue. You still stuck with delay or lag from the mic sound delay from your soundbar. Usually the delay issue comes from soundbars with digital inputs like optical or HDMI (ARC). 

The Mixx 2 Digital Karaoke Mixer solved all the lag issues. Tested working well on many brands of speakers including Yamaha, Samsung, Bose, Philips, etc.