Hey guys, im using the sptool GUI to design and apply filters to noisy ECG signals. I understand the concepts behind lowpass, highpass, and bandpass filters. But I'm confused with the parameters of FDA tool. Here are my questions: 1) In the FDA tool, there is a bandstop filter. what is bandstop? 2) What do the parameters Fstop and Fpass mean? Do they define frequency intervals for the filters? 3) If my guess about 2) is right, why would you need an interval of frequencies of, let's say, lowpass? Aren't frequency intervals only applicable to bandpass filters? I'm very confused. Thanks.