Vandersteen Audio 3A loudspeaker Sidebar 3: Measurements page 4
Fig.8 Vandersteen 3A, impulse response on optimal axis at 50" (5ms time window, 30kHz bandwidth).
Fig.9 Vandersteen 3A, step response on optimal axis at 50" (5ms time window, 30kHz bandwidth).
The cumulative spectral-decay, or waterfall, plot is shown in fig.10. There's some delayed energy in the midrange—again, possibly reflections rather than resonances. The high-frequency response is, however, very clean (the ridge at about 15kHz is due to the computer monitor).
Fig.10 Vandersteen 3A, cumulative spectral-decay plot at 50" (0.15ms risetime).
All told, this is a very fine set of measurements of a very well-designed loudspeaker.—Thomas J. Norton