The 29 Hz @ -3dB is ANECHOIC chamber measurements done by Definitive Technology @ 1 meter away.
Tom Nousaine (Sound & Vision) does his measurements @ 2 meters away in a 7,500 c.f. room.
In my experience, bass limits are @ -6dB or -10dB below the Sensitivity Reference level (usually 85 - 90 dB). When they say "bass limits", they have to specify @ which volume level (like 25 Hz @ 75dB, etc.).
Practically all 3rd party measurements (HT, S&V, etc.) will not be as good as the manufacturer. This is true for most companies including B&W, Paradigm, NHT, etc.
Your small room should get BETTER (lower) bass response than a larger room.