The graphs below are a combination of frequency response, lower part, and phase plot of the drivers, top part. Resolution in the low end is course because of the spacing of the FFT bins. The plots however show a fairly wel behaved phase response. The high part may be a little off because in this set-up it is very important to align the edge of the signal. Since the sample rate is 61.2 kHz there is a possible uncertainty of 15 microseconds. It has to be said that the software allows for a correction factor in case the exact timing is known.
The above graph is for one of the Carver ribbons with 48" baffle. I left the markers for all plots in the same spot to get an idea of "real" numbers.
There is a phase anomaly visible in both plots for the Carver ribbons at approximately 2.5 kHz, indication of a resonance. Note that this resonance is not really pronounced in the frequency plots.
The next plots are from B&G RD-75 ribbons.
Note in the frequency response that the BG ribbons had the supplied passive notch filter installed.
In the above graphs we see a phase jump at approximately 800 Hz. This is accompanied with a dip in the frequency response. As noted before in the "Baffle" section, a dip shows up in that region with larger baffles as well as on the Carver ribbons as with the BG's. To be further investigated.