Floor Loudspeaker Reviews

For logistical reasons, the sample of the Wilson Yvette I measured—serial no. 166, kindly loaned by Manhattan retailer Innovative Audio—was not one of the pair auditioned by Brian Damkroger. I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Yvette's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield and in-room responses.

The Wilson's specified sensitivity is 86dB/2.83V/m; my estimate was a little higher, at 87.6dB(B)/2.83V/m. Wilson specifies the Yvette's nominal impedance as 4 ohms, with a minimum value of 2.94 ohms at 90Hz, which my measurement of the speaker's impedance magnitude confirmed (fig.1, solid trace). The electrical phase angle (dotted trace) is generally low, though a combination of 5 ohms and –47° phase angle at 57Hz suggests that the Yvette will sound best with amplifiers that are comfortable driving 4 ohm loads.

The impedance traces are free from the small discontinuities that would imply the presence of resonances of various kinds. When I investigated the enclosure's vibrational behavior with a plastic-tape accelerometer, I found a resonant mode at 508Hz on the side panels level with the midrange drive-unit, and on the rear panel next to the port that loads the woofer. This was relatively low in level, however; coupled with its high frequency, this means that it will probably not result in audible midrange congestion.

The Yvette's impedance-magnitude plot has a saddle in the bass centered on 23Hz, indicating that this is the tuning frequency of the port. The blue trace in fig.2 reveals that the output of the woofer, measured in the nearfield, has the expected minimum-motion notch at 23Hz, and that the port's nearfield response (red) broadly peaks between 15 and 60Hz. The levels of the woofer and port responses are plotted in the ratios of the square roots of their radiating areas; it looks as if the port doesn't quite extend the output of the Yvette's woofer to its tuning frequency.

The green trace in fig.2 shows the nearfield response of the midrange drive-unit. It rolls off below 200Hz, though with a plateau in its low-frequency output between 50 and 100Hz. The black trace below 300Hz in fig.2 shows the complex sum of the nearfield midrange, woofer, and port responses, taking into account acoustic phase and the different distances of each radiator from a nominal farfield microphone position. The rise in the midbass is due to the nearfield measurement technique, which assumes that the drive-units are mounted in a true infinite baffle; ie, one that extends to infinity in both the horizontal and vertical planes.

Higher in frequency in fig.2, the black trace shows the Wilson's farfield response, averaged across a 30° horizontal window centered on the tweeter axis. Although the overall balance is even, with a slight rising trend in the treble, several small suckouts and peaks are evident between 1 and 20kHz. This kind of response looks worse than it sounds, as to some extent the peaks will be balanced by the dips, reducing any tendency to coloration. This graph was taken without the grilles. Those slightly changed the pattern of peaks and dips, but didn't smooth out the response.

The plot of the Yvette's horizontal dispersion (fig.3) indicates that the on-axis dips do fill in somewhat to the speaker's sides. This graph also shows that, with the fairly wide baffle in which it's mounted, the tweeter becomes very directional above 15kHz, which might correlate with BD occasionally thinking the speakers rolled off the highs a little when he moved his head. In the vertical plane (fig.4), a sharply defined suckout at 1300Hz develops more than 5° above the tweeter axis. This suggests that this is the upper crossover frequency, which is lower than usual for a 1" tweeter.

I examined the Yvette's spatially averaged response in my listening room. (For this I average 20 1/6-octave–smoothed spectra, taken for the speaker placed first in the left then in the right positions using a 96kHz sample rate, in a vertical rectangular grid 36" wide by 18" high and centered on the positions of my ears.) The result, with the speakers driven by an Ayre Acoustics EX-8 integrated amplifier, is shown in fig.5 (red trace). For reference, this graph also shows the spatially averaged response of the Wilson Alexia 2 (blue trace), which I reviewed in July 2018. Though the Yvette has a little more energy in the mid- and high treble than the Alexia 2, the two speakers produce remarkably similar in-room responses, particularly in the bass, where the effects of the room's acoustic modes dominate a speaker's intrinsic behavior.

In the time domain, the Yvette's step response (fig.6) is very similar to that of every Wilson speaker I've measured in the past few years. The tweeter and woofer are connected in positive acoustic polarity, the midrange unit in negative polarity, and the decay of each unit's step smoothly blends with that of the next lower in frequency, suggesting optimal crossover design in conjunction with the slight slope-back of the upper baffle. The slight discontinuity just before 4ms suggests that the best integration of the outputs of the tweeter and midrange unit actually occurs just below the tweeter axis, which is around 40" above the floor with the speakers on spikes. Other than some low-level ridges of delayed energy in the treble, the Wilson's cumulative spectral-decay plot (fig.7) is fairly clean.

Overall, the Yvette offers good measured performance. I'm still astonished by how close its in-room response is to that of the Alexia 2—which costs more than twice as much.—John Atkinson