Meridian Digital Theatre surround-sound music system Measurements DSP6000 part 2
Fig.21 Meridian DSP6000C, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).
Other than a ridge of delayed energy due to the ultrasonic tweeter resonance, the DSP6000's waterfall plot on the tweeter axis (fig.22) is very clean, though with a slight discontinuity at the top of the midrange unit's passband. Despite its large size, the speaker's bass bin is rigidly constructed; on a waterfall plot calculated from the output of an accelerometer fastened to the main panel, only one resonant mode is visible that could have an effect on sound quality: the front. The mode is both sufficiently high in frequency and low enough in level that it should have no effect on the speaker's perceived sound quality.---John Atkinson
Fig.22 Meridian DSP6000C, cumulative spectral-decay plot at 50" (0.15ms risetime
Fig.23 Meridian DSP6000C, cumulative spectral-decay plot of accelerometer output fastened to front panel. (MLS level, -3dBFS; volume control = "70"; measurement bandwidth, 2kHz.)