DAX data

What precisely is DAX data, as in the per slice data? The user guide says it is what is in the passband ("the limits on the Slice Receiver bandpass filter will set the limits on this audio
passband."). I understand, from a question Eric answered some time ago, the data is alternate LRLR etc. How does each doublet relate to some section of the passband? In my head I am trying to compare each datum with a waterfall tile where there is context to what each tile member represents. This clearly isn't the case with the audio. I am running with the CW filter at 400 and each async callback is 256 elements. Where that represents equal LRLRLR, that is 128 separate doublets. However I see nothing that indicates the first doublet of the second interrupt is, at all, related to the last doublet of the first interrupt.