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Sample tools

When one or more samples are selected in the tree, the tool menu contains several tools sorted in 5 categories:

• audio processing,
• fast editing,
• files,
• loop / playback,
• stereo samples.

Using the tools simultaneously on several samples is possible (with a multi selection).

Audio processing

Change volume

You can change the sample volume in three different ways:

• by adding a certain amount of dB (positive or negative amount),
• by multiplying the signal by a number,
• by normalizing the signal so that the maximum of this signal represents some percentage of the maximum intensity.

External command

This tool allows you to use an external command or program to edit a sample. You don't need to export and re-import a sample into Polyphone anymore, everything is done automatically:

1. download an editing software for .wav files such as Audacity or Sweep (Linux),
2. use the tool External command for one or more samples,
3. fill the command line in the field Command to call the external software (you may need to read the documentation of this software), the argument {wav} being mandatory since it is replaced by the path of the exported file (for instance sweep {wav}),
4. edit the sample(s) with the external tool,
5. save the modified version of the wav file(s) with the external tool and close it,
6. the sample(s) will be automatically loaded into the soundfont.

The button on the right of the field helps to select an executable file, and the list History recalls the last commands that have been used. Two options are available:

Authorize stereo editing

When a stereo sample is processed, it is exported with its linked sample in a single stereo file, and both samples are updated when the file is re-imported.

Replace sample information if possible

The loop, the root key and the correction stored in the file returned by the external software replace the ones of the sample. Otherwise, the existing information is kept.

Note: during the process, Polyphone exports a .wav file and will reimport this same file after the external command has been run. If the external command creates other files or saves the result as another file, those files will be ignored and Polyphone will reimport the file initially exported that will probably be not modified.

Filter frequencies

When you use this tool, a window will be displayed showing the frequencies contained in the sample(s) you selected, on a logarithmic scale. Two modes are available:

• Cut frequencies: use the mouse to draw a red area. Everything that is in this area will be removed: the curve gives the maximum level allowed for each frequency, relative to the strongest frequency of the sample.
• Attenuate or amplify: draw the attenuation or the amplification in dB (from -60 to +24 dB) of each frequency. The processing does not create any pre-echo before the attack, and the loop stays seamless.

With the option Note tracking, the horizontal axis is relative to the fundamental frequency of each sample, given by its root key and its pitch correction: ×1 is the fundamental, ×2 the octave, ×3 the twelfth, ×4 the double octave… The same curve then acts on the same harmonics whatever the pitch of the sample: this is useful for giving a consistent timbre to all the samples of an instrument, for example when voicing an organ stop. Hovering over the graph shows the corresponding frequencies for the selected samples.

Note: the mode Cut frequencies cuts the frequencies in a hard way: it is useful for designing a brick-wall filter or removing a noise. For a quick correction, the equalizer of the sample page is simpler to use.

Transpose

The tool asks for a shift in semitones and then resamples the sound to change the pitch.

Fast editing

Load a parameter from the instruments

Parameters at the instrument level can override or offset the parameters defined at the sample level. With this tool, it is possible to fix or complete the sample parameters with what is defined in the instruments using these samples:

• modifying the sample root key with the override defined at the instrument level,
• shifting the sample root key with the “Tuning (semi-tones)” parameter,
• shifting the sample pitch correction with the “Tuning (cents)” parameter,
• defining the sample loop start and end with the loop offset parameters.

Shift a parameter

This tool allows the simultaneous editing, by adding a value or multiplying by a value, of one of these parameters for all selected samples:

• root key,
• correction,
• loop start,
• loop end.

Files

Wav export

After having selected a destination directory, all selected samples will be exported as .wav files.

Loop / playback

Auto loop

The software seeks two positions in the sample, distant and suitable for creating a loop. If needed, a short sound segment is copied with a cross-fade so that the transition at the join location is as smooth as possible. With a stereo sample, the same loop is created for both sides.

If it fails, a warning message appears indicating that no loops can be found (the sample is probably too short or too turbulent).

Warning: This tool modifies the original sample. Modifications can be undone via the “undo” function, but if the file is saved and Polyphone is closed there is no way to step back.

Note: By default, the looping is disabled in an instrument. To hear it, you must select in the Loop playback parameter row of either the Global or individual notes columns in the table. turns it On, turns it Off. turns the looping On and the sample will play to the end after a key is released.

Cross-fade loop

The cross-fade tool can be seen as the manual version of the auto loop tool. First, you need to position the start and end of the loop in the graph around a stable area. Then, this tool creates a loop from these positions by applying a cross-fade whose duration (in milliseconds) is configurable. Everything is therefore configurable but care must be taken when searching for the start and end of the loop:

• at both positions, the harmonics of the sound must match so as not to hear a scratched vinyl record effect during the transition,
• the phases of the different harmonics must also match so as not to hear a frequency cancellation during the cross-fade, which strongly alters the timbre of an instrument,
• as much as possible, the end of the loop must be far from the start to avoid a sound that is too synthetic.

A tip is to focus on positions where the wave crosses the x-axis (value 0).

Remove blank at start

Any blank area before the sample begins is eliminated, reducing the time before the sound is heard. With a stereo sample, the same length is removed from both sides.

Note: this tool may be applied automatically each time a sample is imported, the option being in the software settings.

Trim to end of loop

If a loop is defined for the selected sample, the software will cut the sound after the end of the loop (leaving a small margin at the end).

Note: this tool may be applied automatically each time a sample is imported, according to the software settings.

Stereo samples

Balance adjustment

If the sample is linked to another one (stereo), the software can equalize the mean intensity of the two samples to adjust the balance. This will then make it easier to accurately pan a sample in an instrument. This tool cannot be used with mono samples.

Convert to mono

Each selected stereo sample is converted to mono: a single sample replaces its left and right parts, and the instrument divisions that used either part now use this new sample. Mono samples are ignored, and a message is displayed if the selection contains no stereo samples.

The mono signal is computed from the left (L) and right (R) channels according to the chosen option:

• Sum: L + R, which may cause clipping,
• Average: (L + R) / 2, which keeps the level of a sound centered in the stereo field,
• Constant power: (L + R) / √2, which keeps the loudness of a wide stereo sound (reverberation, spaced microphones…),
• Left channel only,
• Right channel only.

The last two options are not available if a sample has the type link in the sample editor, since the left and right channels cannot be distinguished.

The new sample keeps the sample rate, the loop, the root key and the correction of the left channel, or of the right channel if only this one is kept. Its name is the name of the left channel without the L / R mark: for example, bassoon45L and bassoon45R become bassoon45. If both channels don't have the same length, the shortest one is completed with silence. Channels having different sample rates cannot be mixed: the corresponding samples are left unchanged.

Merge the left and right divisions in the instruments

In each instrument, a division using the left part and a division using the right part are merged if their key and velocity ranges are identical. Their parameters are averaged, a parameter that is not defined in a division taking the value inherited from the global division (or the default value): for example, two divisions panned hard left and hard right give a centered division. Loop playback, Exclusive class, Root key, Fixed key, Fixed velocity and the modulators are those of the left division. If this option is not checked, both divisions are kept and play the new sample.

At the end, a message lists the samples that clipped or that have been left unchanged, and the instruments in which some divisions could not be merged.

Find a link

Among the selected samples, samples whose names only differ by the last letter (L / R) are automatically linked (spaces and the characters -, _, (, ), [, ], {, } and | are ignored in the names). For example, if in a soundfont two samples are called bassoon45L and bassoon45R, bassoon45L will be recognized as the left part of bassoon45R and bassoon45R will be recognized as the right part of bassoon45L.

With this information the right panning will be used when these samples are added in an instrument. You can also benefit from the simultaneous editing of left and right parts in the instrument table if the stereo editing is activated in the settings.

Warning: This tool can break existing links if the names don't match the rule above. A message lists the samples for which no match has been found.

Unlink

All selected samples that are linked (stereo) are unlinked.

Thus, all samples will be processed as mono sounds and they will all have the same panning if they are added in an instrument. The stereo editing, if activated in the settings, will not be applicable anymore.