Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone with an Earthworks microphone preamplifier to measure the Dynaudio Contour 20 Black Edition's farfield frequency behavior and dispersion. I used an Earthworks QTC-40 mike for the nearfield and in-room responses and Dayton Audio's DATS V2 system to measure the impedance magnitude and electrical phase angle.
Footnote 1: EPDR is the resistive load that gives rise to the same peak dissipation in an amplifier's output devices as the loudspeaker. See "Audio Power Amplifiers for Loudspeaker Loads," JAES, Vol.42 No.9, September 1994, and stereophile.com/reference/707heavy/index.html. Footnote 2: This means that the loudspeaker is firing into hemispherical space rather than a full sphere. A speaker that has a truly flat response in the usual "4pi" space will therefore appear to have a boosted upper-bass output with a nearfield measurement, the center frequency of that boost depending on the physical dimensions of the speaker and the woofer alignment. See stereophile.com/content/measuring-loudspeakers-part-three-page-6 or aes2.org/publications/elibrary-page/?id=7171.
Footnote 3: Using the FuzzMeasure 3.0 program, a Metric Halo MIO2882 FireWire-connected audio interface, and a 96kHz sample rate, I average 20 1/6-octave–smoothed spectra, individually taken for the left and right speakers, in a rectangular grid 36" wide by 18" high and centered on the positions of my ears.
Fig.1 Dynaudio Contour 20 Black Edition, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).
Dynaudio specifies the Contour 20 BE's sensitivity as 86dB/2.83V/1m, which was confirmed by my B-weighted estimate. The Contour 20 BE's impedance is specified as 4 ohms with a minimum value of 4.6 ohms. My measurement (fig.1, solid trace) was higher than 5 ohms for the entire audioband, with a minimum value of 4.73 ohms at 192Hz. The impedance is significantly higher in the treble than it is in the midrange; the Contour 20 BE's high frequencies will sound tilted up if the loudspeaker is used with tube amplifiers that have a high source impedance. The electrical phase angle (dashed trace) is occasionally high; the effective resistance, or EPDR (footnote 1), therefore drops below 4 ohms for several regions in the bass and midrange, with minimum EPDR values of 3.26 ohms at 53Hz, 2.24 ohms at 125Hz, and 2.72 ohms at 372kHz. The Contour 20 BE is a moderately demanding load for the partnering amplifier, which will be slightly exacerbated by the slightly lower-than-average sensitivity.
Fig.2 Dynaudio Contour 20 Black Edition, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of sidewall level with the woofer. (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).
There is a small discontinuity at 700Hz in the impedance traces, which implies the presence of some kind of resonance in this region. The Dynaudio's enclosure emitted slight "plinks" when I rapped it with my knuckles. When I investigated the panels' vibrational behavior with a plastic-tape accelerometer, I found low-level resonant modes on the loudspeaker's top and side panels (fig.2). At 285Hz and 414Hz, these are lower in frequency than the impedance discontinuity. As these modes are not high in level and have a high Q (Quality Factor), it is unlikely they will have audible consequences.
Fig.3 Dynaudio Contour 20 Black Edition, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with the nearfield responses of the woofer (blue), port (red), and their complex sum (black), respectively plotted below 310Hz, 850Hz, and 310Hz.
The saddle centered at 46Hz in the impedance magnitude trace in fig.1 suggests that this is the tuning frequency of the woofer's reflex loading. The blue trace in fig.3 shows the nearfield response of the woofer; there is the expected notch at the reflex tuning frequency, which is when the back pressure from the port resonance holds the driver's cone still. The port's nearfield response (red trace) peaks at the tuning frequency, and while its upper-frequency rolloff is smooth, there is a peak in its output between 600Hz and 700Hz, which correlates with the discontinuity in the impedance traces. The 3dB rise in the midbass region in the complex sum of the woofer and port responses (black trace below 310Hz) is due to the nearfield measurement technique, which assumes that the drive units are mounted in a true infinite baffle (footnote 2).
The black trace above 310Hz in fig.3 shows the Contour 20 BE's quasi-anechoic farfield response, averaged across a 30° horizontal window centered on the tweeter axis. The response is smooth and even, with a small excess of energy between 1.5kHz and 2.5kHz and a narrow notch centered at 4.6kHz, which is higher in frequency than the 3.6kHz crossover between the woofer and tweeter. The pair matching between the two samples was superb, meeting ±0.25dB limits between 500Hz and 20kHz.
Fig.4 Dynaudio Contour 20 Black Edition, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.
Fig.5 Dynaudio Contour 20 Black Edition, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 15–5° above axis, reference response, differences in response 5–15° below axis.
Fig.4 shows the Contour 20 BE's horizontal dispersion, normalized to the response on the tweeter axis, which thus appears as a straight line. Other than a slight narrowing of the radiation pattern at the top of the woofer's passband, the dispersion is even and well controlled, which correlates with accurate and stable stereo imaging. This graph also indicates that the narrow suckout in the on-axis response tends to fill in to the speaker's sides. The Dynaudio speaker's radiation pattern in the vertical plane, again normalized to the response on the tweeter axis, is shown in fig.5. A sharply defined suckout in the crossover region develops more than 5° above the tweeter axis, but comparing this graph with fig.3, it looks as if the mid-treble response is a little flatter 5° below the tweeter axis.
Fig.6 Dynaudio Contour 20 Black Edition, spatially averaged, 1/6-octave response in JA's listening room (red) and of the Contour 20 (blue).
The red trace in fig.6 shows the Dynaudio Contour 20 Black Edition's spatially averaged response in my listening room (footnote 3), compared with that of the 2017 Contour 20 (blue trace). The spatial averaging hasn't completely eliminated the small peaks and dips between 50Hz and 500Hz in either speaker's in-room behavior, but the Black Edition's response is generally smoother in the treble than that of the earlier Contour. Both speakers excite my room's lowest frequency mode, but the 2017 speaker's output extends slightly lower in the bass than that of the 2025 Contour 20; its port was tuned to 32Hz compared with the BE's 46Hz.
Fig.7 Dynaudio Contour 20 Black Edition, spatially averaged, 1/6-octave response in JA's listening room (red), of the Magico S5 2024 (blue), and of the GoldenEar BRX (green).
Fig.7 compares the spatially averaged response of the Contour 20 BE (red trace) with those of the Magico S5 2024 I reviewed in August 2025 (blue trace) and of the GoldenEar BRX (green trace). The in-room responses of all three loudspeakers have a downward slope in the treble due both to the increased absorption of the room's furnishings and the speaker's restricted dispersion as the frequency increases. While the GoldenEar has a little too much energy in the treble, the Magico's behavior is textbook. The much-less-expensive Dynaudio comes very close.
Fig.8 Dynaudio Contour 20 Black Edition, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).
In the time domain, the Contour 20 BE's step response on the tweeter axis (fig.8) reveals that both drive units are connected in the same, positive polarity. This is unusual for a speaker that uses second-order crossover filters—see Stephen Entwistle's explanation in the main review text. Note that the woofer's step in fig.8 arrives a little too late to blend perfectly with the decay of the tweeter's step. This suggests that the optimal listening axis is slightly below the tweeter axis, as implied by fig.5.
Fig.9 Dynaudio Contour 20 Black Edition, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).
The Dynaudio's cumulative spectral-decay/waterfall plot on the tweeter axis is shown in fig.9. It is very clean overall. (As always with my cumulative spectral-decay plots, ignore the ridge of delayed energy close to 16kHz, which is due to interference from the MLSSA host PC's video circuitry.)
The Dynaudio Contour 20 Black Edition offers excellent measured performance.—John Atkinson
Footnote 1: EPDR is the resistive load that gives rise to the same peak dissipation in an amplifier's output devices as the loudspeaker. See "Audio Power Amplifiers for Loudspeaker Loads," JAES, Vol.42 No.9, September 1994, and stereophile.com/reference/707heavy/index.html. Footnote 2: This means that the loudspeaker is firing into hemispherical space rather than a full sphere. A speaker that has a truly flat response in the usual "4pi" space will therefore appear to have a boosted upper-bass output with a nearfield measurement, the center frequency of that boost depending on the physical dimensions of the speaker and the woofer alignment. See stereophile.com/content/measuring-loudspeakers-part-three-page-6 or aes2.org/publications/elibrary-page/?id=7171.
