The idea of layering snares is to make one snare sound that has alot of weight behind it, by eq'ing them all the same you are being counter productive. Also, you musnt always eq snares in the same way, it all varies depending on what samples you use.
For instance, if i was to layer two snares together, i would first find one with a high end snap, and another with a punchy low mid sound to it. From there i would put a spectral analyzer on each and see where they peak. I would boost the high snappy snare where it peaks just slightly, and note that frequency. I would then go to the punchier snare, and cut quite heavily around the frequency that i noted from the higher snare.
From there i would group them together and add another eq, and mould to taste