Saturday, March 21, 2015

Equalizer design and Analog Dial Implementation

Design for a vintage styled equalizer interface. Graphics were created for dials and switches: metal slider, animated screw-heads, and back panel inspired by old radio equipment.

It can be considered a test version. Be careful when processing audio with it. There are limiters in place to prohibit peaks, but they can be removed by turning either of the lower brass inlets. now you are free to overload the unit, yet, do so at your own risk. If necessary, one can screw around with the frequency centers using a flat head driver. channel potential is 10-16000hz.

Install the plugin by placing the file into a folder which your vst host will recognize as a plugin repository.

Download VST Plugin

Internal Flow Diagram

eq: internal flow diagram v1

eq: internal flow diagram rebuild
the rebuild version schematic has been reorganized, with wireless links connecting internally, instead of the wires going directly into the eq processors. this allows the main flow to be more clearly arranged above, and the layout of multiple controls below. for easy identification of automation controls, all the names are complete and descriptive. 

The rebuild version is working, and ready to go, as a beta, but the q knobs are too small to be practical. there is also no real representation of how wide each band is, and how one blends with the next. it is adjusted mostly by ear, but the current scheme does not give a good representation of what to expect. i may change it to a horizontal slider, or toggle between wide and narrow.

Internal Controls

A custom control knob module was developed to replace the stock dials. this module allows flexible parameters and graphics options, including: replace background bitmap, rotary indicator, or rotary alpha texture. select conversion to linear, logarithmic, float, or decibel output. custom range input output, variable sensitivity, rotation start-end offset, set zero-point, toggle double-click to zero, motion damping, and output rounding.

rotary control properties panel
integrated edit mode toggle for alignment and resizing

Note: these settings are for the designer to specify, and are not accessible in the final interface element.

Download: Analog Dial Demo

Some of the more interesting internal components developed for this project are detailed below:

analog dial: main internal schematic

Rerange:  A very useful formula for interpolating between two ranges of numbers. this was used for deriving custom range units from 0-1 float values, between sweep range and numerical range, converting view and mouse extents to range limits.

Motion damping: delta division lets the movement slide to a stop, and gives a sense of weight, effectively smoothing changes in float values. this was applied before the rounding option. image rotation is linked directly to this value: what you see is what you get.
motion damping unit


  1. exelente ecualizador para darle caña a esas bocinas amplificadas ;D

  2. i'm happy you found it. Thanks!