Problem with GetSpectrumData

Basically I have a backing track in this "App/game" and the spectrum data which is being fed to a graphical display is working very nicely. The problem is I am using the same AudioSource for the user firing off samples to go along with the backing track like ....

_mainLoopAudioSource.PlayOneShot(_currentSequenceObject.Sounds[_currentSequenceObject.MySequence[CurrentMusicalSequence]]);

These one shots do not show up in the GetSpectrumData on channel 0 or 1 therefore my graphical display is not showing anything but the backing track which is really just a drum line.

Am I missing something or is this to do with me calling them as OneShots ? Should I perhaps be spawning a whole new audio source and adding together the spectrum datas, this I think seems a very sloppy way to do it if I can use one AudioSource to play both the backing track and fire off the samples when the user selects them.

Thankyou in advance

BUMP