A Lynch Mob?
I can find no FFT setting in FM, and the Manual is freely available.
FM is a 32 Bit app.
I would assume Record resolution is up to the interface.
Bit depth is selectable during IR Export. 16/24/32
Incidentally, REW is a 16 Bit app, and when queried JohnPM has presented a cogent case as to why this resolution is totally acceptable for IR work.
I imported the IR's into FM and REW.
In FM the Peak level on the Magnitude scale is -5dB while reading -15dB on the ETC. This looks quite usual if not normal to me. I would rather see dBFS than Magnitude, or misleading terms like SPL.
The Magnitude Response graph displays the result of a Fourier transform contained within the analysis window for the selected impulse response(s). The window’s shape (i.e. Hamming, Half- Hamming, etc.) is taken into account for this calculation.
REW confirms -15dB on the ETC. I rather see them a bit higher, but with FM's 32 Bit resolution and normalise, perhaps these old level analogue or 16 Bit level setting habits should probably be relegated to history.
I always recommend driving the room to ear protection level, and Four 10Second sweeps.
Again I would welcome meters which show dBFS while monitoring input with the usual Over indicators. Just as in most DAW software.
The Graphs should obviously read the same dBFS levels with other Y choices being secondary.
I have not seen such a short and defined decay before. This issue is particular to this measurement only.
FM has two strange behaviours. Visual anomalies can occur at the decay tail. Making the Window as long as the graph range fixes the visual.
The other is the default Watefall settings, these are the two well known issues.
Conversely, FuzzMeasure, has welcome features not seen elsewhere. e.g. Sophisticated combining of measures. Multichannel recording capability.
FM works well with all interfaces, so it is the better tool for taking measurements for Mac users.
EDIT, I am very appreciative of the great piece of work Chris has done in providing us with a wonderful tool. This in the face of very unbalanced competition, i.e. Zero cost.
We may recall when REW didn't function on Mac at all, so FM was the only game in town.
I encourage purchase of his product and support of his ongoing activities.
I also encourage Reading of the Manual.