mic's blog

How do you design a digital wah wah? You take a peak filter and move it down and up the frequency spectrum. From where to where? I do not know. How fast? I do not know.

I have never made as many mistakes preparing a piece of software as I did with the Orinj phase oscilloscope. Some were understandable, some were just not that smart.

A lot of work was done between Orinj versions 2 and 3, but there is always more. My take on what is important and should be implemented soon is below.

Orinj is our software for recording and mixing, with multitrack sessions, wave and MIDI editing, drum loop creation, DSP effects, and so on, and so on. We have now released the beta 3.0.0 version of Orinj. It is available for free download, with some minor limitations as described below.

Five years ago, I wrote a post on the excommunication of the tritone by the catholic church. The tritone is an interval of six semitones (or three tones). The church excommunicated the tritone a long time ago. Presumably, they were hearing it as it used to sound then – with a tuning that was different than the tuning we use today. Today, we tune instruments so that the 12 notes on the chromatic scale split an octave evenly (i.e., the chromatic scale is equally tempered). In the past, tuning tried to get better use of harmonics (for example, the Pythogorean tuning).

We are mixing an album. Everything is progressing well, but there are problems with some of the initial recordings. Most of these are related to vocals. Sometimes they are actual problems, such as the vocal sounds too much like in a box and no amount of equalization can correct for that. Sometimes, it is not clear that there is an actual problem, but the vocalist is not happy either way. Perhaps the melody was not right. Perhaps the melody is correct, but a syllable does not hit the right pitch, there is a glaring "aaa", the timing of a word is out of place, and so on and so on.

A long, long time ago, we used CoolEdit Pro to record and mix our music. This would have been around 2001, on an ancient desktop running a processor at 300 MHz, in our mockup home "studio." At that time, CoolEdit was impressive. I can rant about how great it was for a long time, but here is the important stuff.

10 years ago, I played with Samplitude – a powerful recording and mixing software. I liked it, because it was intuitive. Learning how to use it took little time.

The simplest way to change the pitch of a signal is to simply stretch it or compress it in time. This type of pitch shifting has a disadvantage though, as it also introduces a change in the timing of the signal – it speeds it up or slows it down. It can still be useful, if the signal is short or if its tempo is unimportant. It can be used, for example, for changing the tone of the drum samples used by drum machines or the notes of the wave samples used by MIDI wave mappers.

The following is an example frequency filter that combines the standard low pass FIR filter with a standard second order low pass Butterworth filter. We are doing this to show that we do not have to stick to the standard filter design, but can experiment. Relying on the standard filters is a start, but there is much we can do.