Confused by Dynaudio specs.

Looking at the frequency response figures for the Dynaudio C2, its rated at +/- 2db 28-25000 hz. I was initially concerned about low frequency response with these speakers because of the two small 6.6" (17cm) drivers but after looking over the specs of Dynaudio's other speakers im a bit shocked. Examples:

Dynaudio Contour S5.4 +/- 3db 30-27000 hz. Two 7.8" (20cm) bass drivers. I would have thought these speakers would be much more capable in the lower spectrum because of the two larger bass drivers but these specs dont show it.

Dynaudio Evidence Temptation +/- 3db 29-25000 hz. Same two bass drivers as the C2 but with two 15cm midrange drivers. Here the bass drivers although the same as the C2 arent used for the midrange as two 15cm mindrange drivers take care of that. Again I would think these speakers would be more capable in the low end but the specs dont show it.

Even the C4 is rated at only +/- 2db from 27-25000 hz. What am I missing? Frequency response doesnt seem to be a function of the additional larger drivers. Perhaps maximum output is the advantage? Help me understand this! Thanks

Ive not yet listened to the Contour S5.4 or C2 yet but plan to soon.
Generally, you will get higher acoustic output and greater efficiency/sensitivity from systems with larger drivers. When you see systems with smaller bass drivers rated to delve very low, they may be more linear into the low bass, but they will not play very loud at the lowest frequencies and they will sacrifice some efficiency to get there. So you will need more amplifier power to push them. There are always trade offs and compromises in speaker design; but so far, no designer has found a way to beat the laws of physics.
I have the Dynaudio Contour S3.4's which are rated in the 35hz area for bass frequencies. However when I measured them they went down below 20hz when driven by a 400wpc (into 4ohms) amplifier.
The manufacturers specs are based on anechoic chamber response where no room reinforcement takes place that's why the actual in-room response might actually surprise you.