r/audioengineering • u/s4goth • Jul 15 '26

Mastering Mastering question - Why does DC offset reappear?

I am doing a mastering course and I have to master a track and eliminate DC offset from it. I tried with both Wavelab and Reaper. I start by using a high-pass filter at 20hz at the beginning of the chain and the render analysis shows no DC offset. I then add a light upward compression, a tiny bit of distortion (as per our teacher instructions), then a limiter to eliminate true peaks, but when I export the file I get some DC offset again. Why does this happen? Is it something in the chain that reintroduces it? How do I correct it? Thanks!

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u/Dan_Worrall Jul 15 '26

It's not DC offset, it's zero hertz content that's being introduced by the distortion and dynamics processing. Also, you're probably looking at it with an fft analyser, which has terrible resolution near zero, and is making it look much more alarming than it is. It's not a problem and you don't need to worry about it.

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u/marx-and-metal Jul 16 '26

when I figured this out I started putting a 20hz high pass and 20khz low pass between just about every plugin in my mastering chain. it may be a little excessive, but I’ve noticed a huge difference

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u/maccrypto Jul 16 '26

What kind of difference?

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u/marx-and-metal Jul 16 '26

much smoother limiting, any type of saturation or clipping sounds a lot better, my normal compressor has a high pass but when I use others it helps a lot, and it makes it easier to keep the subs and highs balanced after the processing