I have a signal containing two sine tones 30 kHz and 60 KHz. I used a second order IIR notch filter to filter out the 60 KHz component from the signal, so now the signal has only 30 KHz component.
When comparing the filtered out signal with a pure 30 KHz tone generated, the earlier samples are very much different but later samples are matching to some good extent.
What are the reasons why there is a delay before response being proper? How can i mathematically quantify this?
Like after how many samples the filtered output will be reasonably matching with that of pure tone?