Crack at Loop Point with Some .sf2 Files

• May 24, 2017 - 15:04

I am making a .sf2 using samples from FL Studio, and with Polyphone, it's not too hard. However, as I was testing the Slow Flute instrument, I noticed it cracked at the loop point of at least some of the samples. I have attached the soundfont (which is made with samples from FL STUDIO which is NOT FREE; some of the instruments, though, you can get with the free trial version) and a score to demonstrate the cracking. Set the flute instrument to "Slow Flute" and put it on solo, and you can hear the cracking for yourself.


Attachment Size
Rain_in_the_Forest.mscz 18.38 KB


Creating a soundfont may seem easy at first.
But if it is not formed correctly, the result may not be good.

in Polyphone:
1. First delete all loop start and end points in the "Instrument" section.
2. Instead, select the samples to be looped in the "Sample" section and select "automatic-loop" in the "sample" section of "Tools" in the Top menu (Tools-> Sample-> Auto Loop)
Note: You can select more than one sample in the Tree-View on the left side. (while holding down the Shift key) Flutes and Strings can be looped automatically in this way.

3. Delete all "Vol env attack" and "Vol env release" values ​​in the "Preset" section.
4. Now enter new values:

In the "Instrument" section:
Values ​​to be entered into the "Global" column of each instrument:

for "Vol env attack (s)": 0.003 // This value is required for FluidSynth.
for "Vol env release (s)": 0.6 // The last part of some samples is cut off. Some release effect is required.

In the "Preset" section:
Values ​​to be entered in the "Global" column of each preset:

Harp, Guitar 1 (Hold), Guitar 2 (Hold):
for "Vol env release": 10
// (0.6 * 10 = 6 seconds)

Slow Strings, Slow Flute,
for "Vol env attack": 100
// (0.003 * 100 = 0.3 seconds)

For result, see attachment (There are no crack sounds anymore.):
This "ogg" file is directly exported from MuseScore.
Note: There is rests on start and middle. Flute started playing on 16th and 48th seconds.


Full file:

No crackling sounds after all.

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