Hi, my name is Jon. I’m working on a DJ application with FMOD 4.24.00 on the Xbox360. I have found that sometimes when calling setFrequency on a sound that is playing at 0 volume, crackly distorted noises start playing.

Basically, something like this:

createSound( FMOD_SOFTWARE )
playSound( )
setVolume( 0 ) // user mutes sound, but it continues to play
setFrequency( 0.2 ) // user scrubs sound using DJ controller
setFrequency( 0.5 )
setFrequency( … )

Now the crackly noises start playing. They sound like the sample (distorted, but it is identifiable), and continue until the volume is reset. This behavior is inconsistent; it doesn’t always happen. Sometimes everything sounds just fine.

The data is created with the FMOD sample bank generator, IMA ADPCM on XBox360 and I believe my code is correct, though I’ve been wrong before 😉 Any ideas what might be going on? Thanks very much,

  • Jon
  • You must to post comments


That does sound quite strange but why are wanting to have no volume and increase the frequency?

Does this only happen when you set the volume 0.0?

How about if you place in a very small value, for example 0.01 and see if you still get
any crackly distorted noises?

  • You must to post comments

This is for a DJ program, so I use the setFrequency calls to simulate if the user is "scratching" the record at variable speeds (e.g. for slow forward scratches, I set the frequency to a low value), and the setVolume calls to simulate the DJ mixer. So if the user wants to mute their backwards-scratch with the mixer (a typical DJ trick) I set the volume to 0, but continue to play using negative setFrequency values because they are scratching backwards. It works pretty well except for these crackles.

I have tried using a volume of 0.01 and the crackles still occur :(

Thanks for the idea!

  • You must to post comments
Showing 2 results
Your Answer

Please first to submit.