How to use parametric equalizer on Rio Karma - A s 2005-06-01 12:03:08 I have written a small blog post on how to use Sennheiser MX500 with Rio Karma for best sound quality. It makes use of parametric equalizer and frequency response curves. This is not my original work. I have just gathered some information from various sources and compiled it in this post.Not sure if this is too basic for this forum. Thanks!!