I am generating a sine wave using audacity with 2000 Hz, 30s duration, amplitude 0.5
48 kHz is the sampling rate of the recording device.
I just play and record the generated sound, this is the spectrogram that I get. (Top is original while bottom is recorded) Frequencies other than 2kHz are also showing up in the spectrogram with significant power density. (Using 2048 point hanning window for FFT).
Why does the spectrogram show these higher frequencies and how could I remove them.
I could not find answer to my query on other similar posts in DSP stack exchange thus am creating this post.