A <a href="https://en.wikipedia.org/wiki/low-pass_filter" class="extiw" title="en:low-pass filter">low-pass filter</a>. Hand-crafted by <a href="//commons.wikimedia.org/wiki/User:Vadmium" title="User:Vadmium">User:Vadmium</a> in a text editor.
<a href="//commons.wikimedia.org/wiki/User:Vadmium" title="User:Vadmium">Vadmium</a>
25 March 2007 (upload date)
<span class="int-own-work" lang="en">Own work</span>