Jump to content

An Even Harmonics Waveform For All


BrettM

Recommended Posts

For the last little while I have been experimenting with the Even Harmonics Waveform (EHW) http://www.casiomusicforums.com/index.php?/files/file/933-even-harmonics-waveform/; mainly trying to simulate much sort after “analog warmth”. Layering the EHW with a tone distorted by harsh, ugly, digital XW distortion certainly changes the character of the sound in a pleasant way, although I don't have the gear to vouch for how well it actually simulates tube amp distortion. I usually don't run the EHW through distortion, just blend its volume up underneath the distorted tone until I get a sound I like. Interestingly the soft clipped versions of the EHW haven't been as useful as the raw, unclipped version (split 1) because even soft clipping introduces some odd harmonics.

 

Anyway, the point of this post is to outline how any synth that can layer two oscillators can be used to create an EHW: XW-P1's and G1's, PX-5s's, WK's, CTK's, etc. The basic idea is to use a sawtooth wave and raise it by one octave; then all the harmonics of the sawtooth wave (odd and even) are doubled so they all become even harmonics. Obvious really, but these things always take me a while to figure out.

 

  1. Set osc 1 to a sine wave. This becomes the new fundamental.

  2. Set osc 2 to a sawtooth wave, raised by one octave (pitch +128 on the XW's) and volume set to half of the volume of osc 1.

 

The sawtooth wave's fundamental becomes the EHM 2nd harmonic, the sawtooth's 2nd harmonic becomes the EHM 4th harmonic, the sawtooth's 3rd harmonic becomes the EHM 6th harmonic, etc.

 

It's not mandatory to set the volume of the sawtooth to half the volume of the sine, you can do whatever you want, but this ratio preserves the same 1/n harmonic-to-amplitude ratio found in traditional sawtooth and square waves.

 

It's easy to do this in the XW solo synth with osc 1 and 2, but the PCM sawtooth and sine waves can be layered appropriately as well for a polyphonic version. (Pity the XW PCM sine wave contains vibrato.) Similar layering can be done on many other keyboards.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.