Seismosoft | Earthquake Engineering Solutions

<t>I have a question about filtering. <br/>
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I want to define butterworth bandpass filter, with lower frequecy is 0.1Hz, high frequecy is 70 Hz, and the order is 4. However, the plot gives me a vertivally straight line connecting a point with gain of 1 at 50HZ, and another point with gain of 0 ...