The Raw Audio File will be a recording of the Sweep PLUS the Room.
You will need to Convolve, or is it Deconvolve? that with the original Sweep File, which you probably can Export. This will remove the Sweep leaving an IR of the Room.
Jeff has told us of a software tool which does this at HOLM Acoustics
There may be a Mac convolution app somewhere.
When FM came out first it was a godsend. The price was and probably is in the same league as the PC offerings ETF (and now ARTA).
At the time I did say 'support the pros' and ventured the opinion that a free product would prevent development of commercial offerings.
Pretty obvious prophesies and unfortunately this seems to be happening.
Chris, the FM author, does this for a living and has now branched into iApps.
FM has not seen an overhaul in some time and has some really crippling behaviours in terms of defaulting to absurd settings. A series of incremental Waterfalls is a real chore, involving inputting half a dozen settings each shot.
On the other hand REW has become stable on the Intel Macs at least using the onboard Line Inputs. On top of that the Tool set provided in REW has increased in leaps and bounds. RTA, SLM, etc. etc.
As it stands, FuzzMeasure badly needs an overhaul. However, it is pure natural Mac. i.e. It just works. Point and shoot. If you were to charge for time spent learning to drive REW, even at a basic level, 150 bucks starts to look very fair.
EDIT. The Waterfall doesn't look bad at all to me. I would need to see ones taken at other spots in the room to be sure. It looks quite even with no modes sticking out. I strongly suspect the nulls are BIR.