An air filtration media pack comprising: a plurality of layers of fluted single facer media , the single face media includes a fluted sheet and a bottom facer sheet , a first plurality of flutes arranged in the fluted sheet of a first plurality of layers of fluted single facer media forming a first media section, and a second plurality of flutes arranged in the fluted sheet of a second plurality of layers of fluted single facer media forming a second media section, the first and second plurality of flutes being arranged in a parallel flow configuration, wherein a fluid stream to be filtered diverges into the first and second plurality of flutes, and then converges again later, the first plurality of flutes and second plurality of flutes extending from a first face to a second face of the filtration media pack, a first portion of the first and second plurality of flutes are closed to unfiltered air flowing into the first portion of the first and second plurality of flutes, and a second portion of the first and second plurality of flutes are closed to unfiltered air from flowing out of the second portion of the first and second plurality of flutes, wherein air passing into flutes on one face of the media pack passes through filter media before flowing out flutes on the other face of the media pack; and wherein the first plurality of flutes and second plurality of flutes exhibit differences in flute shape, flute size, flute height, flute width, cross-flute area, or filter media such that the two media sections have distinct pressure loss and loading properties, the difference being at least 5 percent, and wherein the first and second plurality of layers of fluted single facer media are arranged in an intermixed configuration with one or more layers of the first plurality of fluted single facer media alternating with one or more layers of the second plurality of fluted single facer media. a plurality of layers of fluted single facer media , the single face media includes a fluted sheet and a bottom facer sheet , a first plurality of flutes arranged in the fluted sheet of a first plurality of layers of fluted single facer media forming a first media section, and a second plurality of flutes arranged in the fluted sheet of a second plurality of layers of fluted single facer media forming a second media section, the first and second plurality of flutes being arranged in a parallel flow configuration, wherein a fluid stream to be filtered diverges into the first and second plurality of flutes, and then converges again later, the first plurality of flutes and second plurality of flutes extending from a first face to a second face of the filtration media pack, a first portion of the first and second plurality of flutes are closed to unfiltered air flowing into the first portion of the first and second plurality of flutes, and a second portion of the first and second plurality of flutes are closed to unfiltered air from flowing out of the second portion of the first and second plurality of flutes, wherein air passing into flutes on one face of the media pack passes through filter media before flowing out flutes on the other face of the media pack; and wherein the first plurality of flutes and second plurality of flutes exhibit differences in flute shape, flute size, flute height, flute width, cross-flute area, or filter media such that the two media sections have distinct pressure loss and loading properties, the difference being at least 5 percent, and wherein the first and second plurality of layers of fluted single facer media are arranged in an intermixed configuration with one or more layers of the first plurality of fluted single facer media alternating with one or more layers of the second plurality of fluted single facer media. <EOS>