WAVE EDITOR / RECORDER

Convolution Reverb

The Convolution Reverb engine in Edison works by multiplying two audio signals in the frequency domain (in a sort of moving average). A reverb effect is obtained when an 'impulse' file is convolved with the original wave file. Reverb impulse files are created by recording short, sharp sounds in real spaces or through a reverb/effects unit. The recorded 'reverberance' is an acoustic fingerprint of the real space. This technique is equivalent to sampling an acoustic instrument and allows us to 'borrow' impulses from very expensive hardware or real spaces that we would never have the chance to record in. Naturally, the internet is brimming with free impulses for your downloading pleasure (see 'Impulse Resources' below).

NOTE: While called the Convolution Reverb, any audio file can serve as a source for the impulse making this a general convolution tool. As always, experimentation will reward you with unique and interesting sounds.

To Open the Convolution Dialog

To open the dialog you can either left-click on the Convolution Reverb button , press Ctrl+R inside Edison, or use the Tools > Spectral > Convolution Reverb option.

Once an impulse is loaded you can perform any of Edison's editing functions in the spectral preview window. Right-click on the spectral preview to open the editing options.

Options

• Delay - Adjusts the delay between the onset of the reverb and the source wave.
• Dry - Adjusts the level of the dry signal.
• Wet - Adjusts the level of the wet signal.
• Use data outside selection - The reverb can operate on a selection of a wave. When selected data from outside the selection is used to create the reverberant sounds. When no selection is made the whole sample is effected and this option is greyed out.
• Add tail - Adds new reverberant data beyond the end of the original file.
• Accept - Applies the impulse to the wave. To undo the reverb press Ctrl+Z.

Impulse

This section displays a spectral view of the impulse function. The vertical axis represents frequency 0 Hz (bottom) to 20 kHz (top) and the horizontal axis represents time. You can zoom and scroll through this display by left-clicking in the scroll bar above the display (as shown by the double arrow cursor in the screenshot above).

• Load Impulse - Left-click on the 'Impulse:' tab above the spectral display and a standard 'Load File' dialog will open.
• Envelopes - There are several standard envelope controls along the bottom of the window that act on the reverberant sound. These envelopes provide enormous creative potential.

Left click the symbols to apply, from left to right -

• Pan - To edit the Pan envelope.
• Volume - To edit the Volume envelope.
• Stereo Separation - To edit the Stereo Separation envelope.
• All-purpose envelope - Can be assigned to playback velocity/direction and various other functions.

Editing envelopes - After selecting the desired envelope type, right-click in the 'Impulse Editor Window' to add points, and left-click to move points and tension markers. Right-click points to open a context menu that will allow you to delete points or change the curve type.

Impulse Resources

Edison comes with many impulses, however the addictive nature of these files will mean that you will soon be looking for more. Below are several links to get you started. To load a new impulse from outside FL Studio, left-click on the 'Impulse:' tab above the spectral display to open the standard 'Load File' dialog and browse to the location of the new impulses.

• Noise Vault - Nice resource for public domain reverb impulse files.
• Fokke van Saane's impulses - Many of the impulses here are .aif format and so are not suitable for Edison (uses .wav format impulses), however you can convert them to .wav format using the demo version of GoldWave. We have included Fokke's site mainly because he clearly explains how the impulse\ files were created and posts lots of great pictures of the spaces in which the impulses were made, be inspired!
• Google for 'Reverb Impulse' - Be brave, find your own!

Action Buttons

• Preview - Audition the current settings without applying them.
• Accept - Process and paste (replace) the original selection.