bluetooth 4.0 vs 4.2 for subwoofer

I am getting a subwoofer but one is 4.0 and the other 4.2. The 4.0 is cheaper and i already have one that is 4.2 and i notice a slight lag between the bass and the action with the rest of the wired audio. Would a 4.0 sub have even more of a delay?

Anyone with experience with 4.0 and 4.2 who can help me would be appreciated. i only have experience with 4.2.