1. From the Insert menu, choose Synthesis, and choose FM from the submenu.

  2. In the Total output waveform length box, specify the length (in seconds) of the generated waveform.

  3. Choose a position from the Insert waveform at drop-down list to specify where the generated waveform will be placed within the current data window.

  4. Drag the Configuration slider to determine the arrangement and number of operators to be used.

  5. Modify each operator as desired.

  6. Click the OK button.

When you drag the Configuration slider, a graphical representation of the arrangement and number of operators that will be used is displayed:

Sound Forge Pro operatorconfig FM Synthesis

  • The outputs of operators joined horizontally are simply mixed together. The outputs of the bottom operators are mixed together to form the final output. Mixing different simple waveforms is called additive synthesis.

  • Operators joined vertically are FM carrier-modulator pairs. The bottom operator is the carrier, and the top operator is the modulator.

  • Operators that have no other operator directly above are simple waveform generators.

  • When three or more operators are stacked, the top operator modulates the operator below it, which modulates the following operator, and so on.

  1. Click a Current operator radio button to choose the operator that you want to modify.

  2. Adjust the envelope graph to modify the amplitude of the operator over time:

  • Drag the small envelope points up or down.

  • To create a new envelope point, double-click the envelope.

  • To delete an envelope point, right-click it and choose Delete from the shortcut menu.

  • To change the fade curve between two points, right-click an envelope segment and choose a command from the shortcut menu:

Fade Type

Fade In/Out Envelope

Linear Fade

Sound Forge Pro envelope linear FM Synthesis

Fast Fade

Sound Forge Pro envelope fast FM Synthesis

Slow Fade

Sound Forge Pro envelope slow FM Synthesis

Smooth Fade

Sound Forge Pro envelope smooth FM Synthesis

Sharp Fade

Sound Forge Pro Envelope sharp FM Synthesis


Sound Forge Pro Envelope hold FM Synthesis

  • To move all envelope points, press Ctrl+A and drag when the envelope has focus (the cursor will be displayed as a Sound Forge Pro handpointer FM Synthesis).

  1. Choose a waveform shape from the Operator shape drop-down list.

  2. In the Frequency box, specify the frequency of the operator.

  • Sound Forge Pro note FM SynthesisNotes:

  • If Frequency is set to 0.00, a DC (zero-frequency) waveform is produced regardless of the waveform specified.

  • When you choose Filtered Noise from the Operator shape drop-down list, Frequency determines the high-frequency content of the noise.

  1. Drag the Feedback slider to determine the amount of the operator’s output that is used to modulate itself. If the operator is also being modulated by another waveform, the feedback path and the modulator output are mixed together to modulate the carrier.

  2. Drag the Amplitude fader to determine the output gain that will be applied to the current operator after the amplitude envelope.

  3. If the operator is a modulator, this control, along with the envelope, determines the amount of frequency modulation applied to the carrier. If the amplitude of a modulator is high, very harsh sounds can result.

FM Synthesis

Insert Menu:

From the Insert menu, choose Synthesis, and then choose FM from the submenu to create complex sounds from simple waveforms using frequency modulation (FM).

In frequency modulation, the frequency of a waveform (the carrier) is modulated by the output of another waveform (the modulator) to create a new waveform. If the frequency of the modulator is low, the carrier will be slowly de-tuned over time. However, if the frequency of the modulator is high, the carrier will be modulated so quickly that many additional frequencies, or sidebands, are created.

In Sound Forge software, up to four waveforms (operators) can be used in a variety of configurations. Depending on the configuration, a waveform can be a carrier, a modulator, or a simple, unmodulated waveform.

What do you want to do?

Sound Forge Pro arrowdn FM Synthesis Generate a waveform

Sound Forge Pro arrowdn FM Synthesis Specify the number and arrangement of operators

Sound Forge Pro arrowdn FM Synthesis Modify an operator

For more information about using processing dialog controls, click here. 

Sound Forge Pro btnshowall FM Synthesis

FM Synthesis