Waveshaping with a wavetable

Having tested a simple waveshaper with Squarer, I wondered if I could take the audio processing part and add it to the Wavetable Creator and make a more flexible wave-shaping utility. As it turned out, doing this went a lot faster than I expected and I rapidly had it working. So please welcome ShaveWapery 0v04.

ShaveWapery uses the same user interface as Wavetable Creator, but changed to the more fashionable 'dark' look, and using my standard lilac as the key color (there's now no chance of mixing the two utilities up!). You choose source waveforms from the on/off boxes at the top, set their amplitude and other parameters, and then press the 'Generate' button. The resulting waveshape appears in the box on the left and its spectrum is displayed underneath. But instead of just allowing you to export the wavetable, in ShaveWapery, it immediately becomes available as a transfer function for a waveshaper.

As always with transfer functions, starting off with a linear input/output relationship is always a good idea. In this case, a sawtooth produces a linear transfer function:

 and any audio should pass through mostly unaffected. Moving the 'Sharpen' control anti-clockwise should give a very similar 'squaring' of the sound to Squarer. And unlike the 'Saturator' built-in effect in Live, ShaveWapery allows you to add randomness to the transfer function:

which can produce some very interesting effects that are noise-like but also structured. There is an enormous range of things to try here, so explore away. As with all such waveform-based processing, if you input monophonic audio, then you will get monophonic output, but if you input polyphonic audio, then you will get distortion. I did thinking about calling this the Intermodulator, but I prefer ShaveWapery!

I'm currently working on improving the user interface - I'm not happy with the 'Generate' button, for instance. But this is just the first iteration.

As usual, ShaveWapery can be downloaded from MaxForLive.com .

Related articles

• Turn your Arduino into a 4 voice wavetable synth with only a few components...

Wavetables as sound effect sources

I've always been a fan of wavetables. The direct relationship between a block of memory holding waveform information and the resulting sound is useful in lots of ways, particularly if you go beyond the basic 'linear read'.

Previously, I've released some of my early experimentation in M4L with wavetables, and the latest revision is now available: Wavetable Sound Effects 0v04. (from Maxforlive.com) Compared to the previous versions, there are more wavetables, more control over the scanning through the table, and a better user interface that makes it very clear where the LFOs are and what they do. Each wavetable is just 2 seconds in length, but the sound making possibilities are much wider than this might suggest.

As usual with most devices, start off by turning the LFO modulation levels down to zero. In this case there are three: Vibrato for frequency modulation, Rangato (range-ato) for the modulation of the range of table scanning, and Timbrato (timbre-ato) for the modulation of the centre of the table scan. Once you are familiar with the basic operation, then you can return to the LFO modulation and explore how it affects the sound.

Basic operation centres around the main controls, which are in the dark backgrounded area. The Table selection chooses between ten very different sets of audio files (hand-crafted from scratch in Audacity). The Start and Finish controls adjust the region of the wavetable that will be scanned and turned into audio, and the triangle sets the centre of the region - if the white area is outside of the window, then nothing happens (the limits are hard-coded), so there's no need to explore what happens if you do this.

The Freq (uency) control sets the rate at which the region is scanned and thus turned into audio, and the High/Low button on the right controls how quickly this happens. underneath the Freq control is the Shift control, which enables the output pitch to be changed independently of the scanning rate. The sound sometimes vanishes if you set the Shift control too high, so explore the left hand side of the dial first...

The Range control provides more scanning control, and the indicator bar next to it shows the total modulation being applied to the scanner.

That's about it really. Explore and enjoy!

Related articles

• PPG WaveGenerator for Mac
• Atmegatron is an 8-bit mono synth
• WaveTable name has changed to PeriodicWave
• FireBird 2, "Harmonic Content Morphing" Synth Plug-in, Now Free [Windows]

Wavetable Sound Effects 0v03 - Update!

After getting my head around some of the features of Max again (like having to make sure that you use 2000. to indicate a float instead of 2000 which is an integer), I've now updated my Wavetable Sound Effects Max For Live (M4L) instrument to version 0v03. The intermediate 0v02 version was superceded during testing of a different wavetable device that I'm still working on...

This new version has much the same principles behind it, but now allows finer control, and has better LFOs. The new LFOs include a 'Shape' control that samples the waveform and gives a kind of Sample/Hold effect, plus there's now a frequency modulating LFO for each LFO, which extends their usability quite a lot. I also added three new wavetables, so there's lots more sound generating capability. This device is intended to be explored, much as one would do with the analogue synths of old like the EMS VCS3... So feel free to explore.

You can find it on the Max For Live dot Com library site here.

Related articles by Zemanta

• Deep Synth - Dynamically Generated Oscillators (netnewmusic.net)
• New synth engine for Arduino Pocket Piano! (makezine.com)
• In my day, we didn't have oscilloscopes ... we used fire! (makezine.com)