Re: [Audacity-nyquist] dc bias and hp filters

[David R. S. <dav...@sh...>]

Thanks Roger. To my ears it sounded best when I used a highpass filter at 
20Hz, and Edgar confirmed this by what he saw on the Audacity screen.

Thanks

David

On Sun, 4 Dec 2005, Roger Dannenberg wrote:

> 	In practice, what you really want to get rid of (in my opinion) is
> very low, inaudible frequencies, not just the "zero Hertz" DC bias. E.g. if
> there were a sizeable component at 0.1 Hz, your DC bias could be zero, but
> the signal would alternate between positive bias and negative bias every 10
> seconds. I'm not sure how this would happen in real recordings, but I've
> seen it happen in digital audio effects in Nyquist. The high-pass filter is
> by definition the way to get rid of the low frequency terms.
>
> 	-Roger