The black trace below 300Hz in this graph shows the complex sum of the nearfield woofer and midrange output above 300Hz, it shows the V3's farfield response averaged across a 30° horizontal window on the tweeter axis. Both the woofers' and the midrange unit's low-pass rolloffs also appear to be second-order.
Peculiarly, the woofers had a small peak evident at 105Hz, before beginning what appears to be a smooth second-order rolloff to hand over to the midrange unit above 180Hz (fig.3, blue). This is confirmed by the sum of the woofers' nearfield responses measured with DRA Labs' MLSSA system (fig.3, red trace the two woofers behaved identically). The peak centered at 33Hz in the impedance-magnitude trace suggests that this is the tuning frequency of the twin woofers, equivalent to the frequency at which the speaker's anechoic response will be down 6dB. The facts that the area affected is small and faces away from the listener will mitigate any audible consequences of this behavior.įig.2 Magico V3, cumulative spectral-decay plot calculated from the output of an accelerometer fastened to the center of the rear panel (MLS driving voltage to speaker, 7.55V measurement bandwidth, 2kHz). However, a small section of the rear panel immediately behind the midrange unit was quite lively between 375 and 550Hz (fig.2). When I listened to the panels with a stethoscope while playing the stepped toneburst track on my Editor's Choice CD (Stereophile STPH016-2), the front baffle was inert, as were the side panels. The traces in fig.1 are free from the small wrinkles due to the presence of cabinet panel resonances when I investigated the enclosure's vibrational behavior with an accelerometer, I could find no resonant modes. Overall, the V3 is a demanding load that should be partnered with amplifiers that have no problem delivering high currents.įig.1 Magico V3, electrical impedance (solid) and phase (dashed). There is also a combination of 4 ohms and a –50° capacitive phase angle at 4kHz.
The speaker's impedance (fig.1) remained below 4 ohms for much of the audioband, with minimum values of 3 ohms at 97Hz and 2.7 ohms at 7kHz. My estimate of the Magico V3's voltage sensitivity was 87dB(B)/2.83V/m, slightly lower than specified.
0 kommentar(er)
