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index a2b2914..c60a5bb 100644
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+++ b/README.md
@@ -225,6 +225,8 @@ python redilysis.py -v -m bpm -s 3 --bpm-min 100 --bpm-max 200
 
 This mode is less sure that the spectrum mode.
 
+It must absolutely run with multiple seconds interval to work well. Three seconds is a correct minimum.
+
 It attempts to detect beats based on audio "jumps" in intensity and energy.
 
 To correct a well-known error called the "octave error" where the detected tempo is twice/half or thrice/third of the real tempo, you can use the Min/Max BPM. When the calculated tempo is outside of the range, it will attempt to find more legitimate values.