FM Synthesis Of Metallic Sounds

This video – the first in a series by Element433 on FM synthesis – takes a look at using FM to create a variety of metallic sounds.

“The idea of this series is to show how to improve on the original ‘plasticky’ sounding F.M. presets that were/are so ubiquitous on the original F.M. synthesizers of the 1980s,” they note.

Each example in the video has a “structure” (synthesis parameters) and a “creative” context, which in this case are short film clips.

Here’s what they shared about the technical details:

Synthesis Parameters

C = Carrier M =Modulator (As shown in VOPM)
Detune is for slightly detuning for phasing and chorusing effects

The most universal F.M. parameters (mainly frequency ratio data) are provided from which to create variations of the “material” timbres in the videos. For example, you will be surprised how much variation is possible by changing the fundamental frequency and the inharmonic frequencies of the bells.

Frequency Ratios

Frequency ratios and detune settings are provided for FB01/CX5 4 operator and DX7 (in red).

Levels and Envelopes

Level and envelope data varies quite a lot depending on the model of F.M. device you have so they were omitted here, however, it is fairly easy to work them out by listening and following the order in the video.

1) Make sure you have the correct algorithm.

2) Start with the first operator as the loudest operator (full level). Then get the level for each subsequent operator. Follow the order in which they are switched on in the video and experiment to get the timbre as close to the videos as possible.

3) The envelopes are pretty easy to work out if you listen to each operator as it is switched on in the video.

If you are are still stuck, I recommend learning the basics of FM.

3 thoughts on “FM Synthesis Of Metallic Sounds

  1. Absolutely great for anyone using or working with F.M. sounds. Cool sounds protraied. Very happy with that, thanks!
    Nonetheless some remarks:
    – Missing the physical background driving the algorithm choice and frequentie ratios.
    – Can’t agree with plasticy sounds of the CX-5M (wrote some F.M. editing software for that!) or the DX series. There were truly physically modelled and great sounds in there.

    And, although the sounds in this first video of the series seem to be lacking some physical reality they are close enough with added twists and deepness. No effects used, and no modulation other than envelopes, people.
    Great! Synthesis! Sound design!

    Thank you again.

  2. Very good tutorial, much more clear than usual. I’ve turned to physical modeling over FM because its far less fidgety to program if you’re looking for most of these sounds. Its also a bit less static & breathes more, where FM is so clean, it can require a lot of added work to make things playable. There are now several more advanced FM options that take on a lot of the heavy lifting from the days of that teeny DX7 display. I just find physical modeling to be a more workable form o’ synthesis.

  3. This video prompted me to look at a bit of research into bells and how they are tuned (as I’m a fan of physical modelling, and I didn’t think that first bell tone was too good).

    Some really good resources here:, including showing the envelope shapes over time of the main frequencies – might not be what you’d expect!!

    Of course, you’ll need to learn about the terminology used by bell-makers.

    So ideally you need at least 6 sine oscillators to make a credible bell sound using additive synthesis!

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