Hi, you get this error because the audio levels is a parameter that needs 2 values (one for the left channel and one for the right channel). It's not clear, because the parameter only shows one gain value, which it will apply automatically on both channels. To fix your expression you just need to change your value -10, into a table of 2 values [-10,-10]. So it should work like this: if(comp("audios").layer("files").effect("Slider Control")("Slider")==1)[-10,-10]; else [-100,-100] Hope this helps
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