<story><title>Geometric intuition for digital audio filters</title><url>https://karlhiner.com/jupyter_notebooks/intro_to_digital_filters</url></story><parent_chain></parent_chain><comment><author>anyfoo</author><text>Julius O. Smith&amp;#x27;s books are excellent, easily ranking up amongst the best text books I&amp;#x27;ve always read. It&amp;#x27;s always a good sign if I look forwarding to continue reading as if it were a novel...&lt;p&gt;You can actually read them for free online: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;ccrma.stanford.edu&amp;#x2F;%7Ejos&amp;#x2F;Welcome.html&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;ccrma.stanford.edu&amp;#x2F;%7Ejos&amp;#x2F;Welcome.html&lt;/a&gt;
I picked up printed copies on Amazon regardless, both because I wanted to support the author after reading almost a full book online, and because I sometimes prefer reading a physical textbook (the &amp;quot;spatiality&amp;quot; somehow helps me remember better).&lt;p&gt;I&amp;#x27;m a Software Engineer without any background in signal processing (or audio), and stumbled upon his books when an FPGA hobby project of mine involved a simple audio pipeline for which I wanted to do some sample rate conversion. Since then DSP has become a hobby on its own.&lt;p&gt;I actually read the &amp;quot;Digital Filters&amp;quot; book (the second in the series) first, before reading the first book about DFT fundamentals, and it worked pretty well.</text></comment>
<story><title>Geometric intuition for digital audio filters</title><url>https://karlhiner.com/jupyter_notebooks/intro_to_digital_filters</url></story><parent_chain></parent_chain><comment><author>mrob</author><text>Good article, although in reality removing 60Hz hum isn&amp;#x27;t so simple, because it&amp;#x27;s never a pure sine wave. You get harmonics too, and the ear is more sensitive to those higher frequencies so they can be a problem even at lower amplitudes.</text></comment>