# Note pitch help (warning science involved)

Instruments and Gear
 DanielM 1 Feb 2012 08:21 | Quote Joined: 11 Apr 2011United Kingdom Lessons: 1Karma: 12 First off I know I've spent a long time silent on the forum but university life is hectic as, I still don't know how I keep the work balanced and achieve good grades but anyways that's beside the point of why I've popped in. I'm trying to based off some of the lectures on AC circuit theorem construct a simulation of a low pass filter using reactor. I know how to mathematically express it but I've hit a snag... The formula for the gain of the wave after being ran through the low pass filter is g=1/(sqrt(1+(w^2)(R^2)(C^2))) were w=angular frequency of the wave, R resistance and C capacitance. I know w=2pi*f were f is frequency of the wave, but reactor doesn't have an input for the angular frequency of frequency of the pitch playing it just has an input of pitch. So what I was wondering is if anyone knew how to mathematically convert and inputted pitch into frequency unless of course there's a nicer way than getting the equation for pitch into frequency and subbing it in in which case you are amazing :D I'm looking into now cause I have a feeling reactor may output pitch in a frequency value to allow the user to create fine tunes etc so I'm revising my reactor knowledge but if anyone has a quick easy answer it would be much appreciated.