B1 is a loop from of an old g-funk tune. Wasn't sure at first, but I think it works pretty well. Just a bit of fun, right. What next? ...Probably a housed-up loop of Warren G or some Dre Day samples. Maybe even Ice Cube's 'It was a good day'. The g-funk house revival is on.
B1 sounds to me like a rehashed take on Futers' Mackin', but with less soul. A1's samples have been overdone enough for my ears, and the repetitive, chopped performance doesn't really help it. Mic Mills pulled this vibe off real well with Wonderland on Big Doint 001.