I understand how to get curve 1,2,3 and 4. the last step is "The overall curve is shifted vertically by an amount determined by the multiplicative constant of the transfer function''. as you can see the multiplicative constant is 20dB but what I don't get is how does this result in curve 5? in other words how they got curve 5 from shifting everything by 20dB so that the gain is 60dB? can anyone explain this for me please?
Curve 1 rises from a zero and ramps up to intersect the 100 rad/sec point at 40 dB. At this point curve 2 cancels the rise to a flat line remaining at 40 dB. Curve 3 comes along at 100,000 rad/sec and starts declining the "flat" to a 20dB/decade slope downwards.
Curve 4 raises the whole thing by 20 dB to coincide with curve 5 on the diagram.