I'm showing some benefits of combining the heavy Greenbacks (G12H) with the medium ones (G12M) in a 4x12. It's more powerful than you may think. Alone G12H is full, punchy but with a harsh top end and G12M alone is bright and warm but a bit too compressed and not enough bite. Combined they actually range from early electric blues to modern metal!
Gear:
2020 Marshall Mini Silver Jubilee 20W
1971 Marshall 1960B with
2x 1971 G12H30 55Hz T1281 Pulsonic Greenbacks
2x 1968, 1973 G12M25 75Hz T1221 Pulsonic Greenbacks
2013 Gibson SG CS Aged with a Potted Burtbucker 3 in the bridge.