SSP Screenshot

FFT lengths supported by SignalScope Pro appear below in four groups.  The first group includes FFT lengths that are powers of 2.  The second group includes FFT lengths that are recommended for sample rates that are multiples of 32 kHz.  The third group includes FFT lengths that are recommended for sample rates that are multiples of 44.1 kHz.  The fourth group includes FFT lengths that are recommended for sample rates that are multiples of 48 kHz.

Powers of 2
FFT Length Visible Spectral Lines Spectral Lines w/Guardbanding
256 128 100
512 256 200
1024 512 400
2048 1024 800
4096 2048 1600
8192 4096 3200
16384 8192 6400
32768 16384 12800
65536 32768 25600
131072 65536 51200
262144 131072 102400
524288 262144 204800
1048576 524288 409600


Recommended for Fs = 32, 64, 128 kHz
FFT Length Visible Spectral Lines Spectral Lines w/Guardbanding Frequency Resolution w/Fs = 48 kHz
1000 500 390 32 Hz
2000 1000 780 16 Hz
4000 2000 1560 8 Hz
8000 4000 3120 4 Hz
16000 8000 6240 2 Hz
32000 16000 12480 1 Hz
64000 32000 24960 1/2 Hz
128000 64000 49920 1/4 Hz
256000 128000 99840 1/8 Hz
512000 256000 199680 1/16 Hz
1024000 512000 399360 1/32 Hz


Recommended for Fs = 44.1, 88.2, 176.4 kHz
FFT Length Visible Spectral Lines Spectral Lines w/Guardbanding Frequency Resolution w/Fs = 44.1 kHz
882 441 350 50 Hz
1764 882 700 25 Hz
4410 2205 1750 10 Hz
8820 4410 3500 5 Hz
17640 8820 7000 2.5 Hz
22050 11025 8750 2 Hz
44100 22050 17500 1 Hz
88200 44100 35000 1/2 Hz
176400 88200 70000 1/4 Hz
352800 176400 140000 1/8 Hz
705600 352800 280000 1/16 Hz
1411200 705600 560000 1/32 Hz


Recommended for Fs = 48, 96, 192 kHz
FFT Length Visible Spectral Lines Spectral Lines w/Guardbanding Frequency Resolution w/Fs = 48 kHz
750 375 300 64 Hz
1500 750 600 32 Hz
3000 1500 1200 16 Hz
6000 3000 2400 8 Hz
12000 6000 4800 4 Hz
24000 12000 9600 2 Hz
48000 24000 19200 1 Hz
96000 48000 38400 1/2 Hz
192000 96000 76800 1/4 Hz
384000 192000 153600 1/8 Hz
768000 384000 307200 1/16 Hz
1536000 768000 614400 1/32 Hz