Alchemy formant filter controls

Source components are shown only in advanced view. Click the Advanced button to switch to advanced view, then click the A/B/C/D button to select the source you want to edit.

The parameters in this section are shown when the Formant button is active in an additive or spectral source subpage.

When audio is imported into the additive or spectral engines with the Formant option enabled, the signal is analyzed and resonances in the original signal are extracted and converted into a formant filter shape. See Alchemy Import browser.

The formant filter scales the amplitude of additive partials or spectral bins over time to recreate the characteristic resonances of the instrument, rather than processing the audio signal like a conventional filter.

Figure. Formant filter parameters.

Formant filter analyzed parameters

The analyzed controls work only if you enable the Formant button in the Import browser when importing your audio files. This more detailed analysis attempts to determine the resonant frequencies of the source audio data.

Formant filter synthesized parameters

The synthesized controls work with any additive or spectral material and do not require the formants to be analyzed on import. Use these parameters to impose new resonant characteristics on the original signal. The default settings provide a range of vowel sounds: use the Select knob to morph through the default “a,” “e,” “i,” “o,” and “u” vowel sounds loaded into the four slots to the right.

Modify formants in a resynthesized additive guitar sound

  1. In the Name bar, click the File button and choose Initialize Preset from the pop-up menu to reset all Alchemy parameters to default settings.

  2. Select source A, then click the source select field and choose Import Audio from the pop-up menu.

  3. In the Import browser window, click the Additive and Formant Import Mode buttons.

  4. Navigate to the Guitars subfolder in the Factory samples folder, and choose a single guitar sample.

  5. When loading is complete, click the Formant button to the right side of the source A window. Note that the upper Analyzed section is turned on.

  6. Adjust the Shift knob to move resonances up or down in frequency and to change the timbre. Small amounts of Shift variation work well for subtle changes: try a few semitones in either direction.

  7. Play some very low notes, then some very high notes. Gradually turn down the KTrack knob to reduce key tracking for the formant filter, and note the difference when you replay the high and low notes.

  8. Adjust the Size knob value to change the apparent size of the guitar body. Also adjust the Center knob value, and note the effect it has on the tone of the resulting larger or smaller guitar body.

Modify formants in a resynthesized spectral drum loop

  1. In the Name bar, click the File button and choose Initialize Preset from the pop-up menu to reset all Alchemy parameters to default settings.

  2. Select source A, then click the source select field and choose Import Audio from the pop-up menu.

  3. In the Import browser window, click the Spectral and Formant Import Mode buttons.

  4. Navigate to the Loops subfolder in the Factory samples folder, and choose a drum loop.

  5. When loading is complete, click the Formant button to the right of the source A window. Note that the upper Analyzed section is turned on.

  6. Adjust the Size knob value to make the drums seem bigger or smaller.

  7. Adjust the Smooth knob value to alter the rate of change for the formant filter. Higher values smear the timbre of one drum into the next. Lower values exaggerate changes and create an unusual distortion near the bottom of the knob range.

Create a talking additive sound with synthesized vowel formants

  1. In the Name bar, click the File button and choose Initialize Preset from the pop-up menu to reset all Alchemy parameters to default settings.

  2. Select source A, then turn off the oscillator in the VA section to the right.

  3. Click the Additive button, and turn on the additive section. You will hear an additive sawtooth sound if you play some notes.

  4. As an option, increase the Num Partials value. This helps to prevent the sound becoming dull if played in lower registers.

  5. Click the Formant button, and turn on the lower Synthesized section. Play a few notes to hear the “a” vowel sound that is imposed on the sawtooth wave.

  6. Increase the Select knob value, and play a few notes. Note how the vowel sound morphs to an “e,” then an “i,” then finally a “u” at 100%.

  7. Reduce the Select knob value, then modulate it with a new AHDSR envelope (AHDSR2), and leave the depth at +100%.

  8. Set Sustain to zero for the AHDSR2 envelope. Note the “yeah” articulation this creates as you play each note.

  9. Increase the Attack time for the AHDSR2 envelope. Note the “aya” type articulation this creates as you play each note.

  10. Adjust the Shift knob, the Size knob, and the Center knob, to explore the different timbres available.

  11. Switch the order of vowels in the four pop-up menus, and also load different filter types such as Comb.