![]() I'm not surprised that Audio Note recommends placement close to the wall behind it. ![]() Bearing in mind that this trace includes the usual 2pi boost in the upper bass that results from the nearfield measurement technique, it looks as if the AN-E really doesn't produce as much bass as you might expect. The speaker's bass is well extended, but does shelve down below 120Hz. However, the woofer rolls off a little early for the port to extend the speaker's output down to the port tuning frequency.įig.4 shows the Lexus Signature's response on the tweeter axis at 50", averaged across a 30° horizontal window, spliced at 300Hz to the sum of the nearfield woofer and port responses, taking into account both acoustic phase and the distances of the two radiators from a nominal farfield position. The port's response does indeed peak at 29Hz (fig.3, left-hand trace), with the woofer's output showing the usual notch at this frequency. However, the saddle centered on 29Hz in the impedance graph (fig.1) suggests that this is the tuning frequency of the rather small port at the base of the cabinet's rear. The optimistic specification lists the AN-E's –6dB point as 17Hz, implying that this is the port tuning frequency. ![]() The crossover to the tweeter appears to be set at 3kHz, which is both higher than specified and a bit high for a woofer of this relatively large diameter.įig.3 Audio Note AN-E Lexus Signature, acoustic crossover on tweeter axis at 50", corrected for microphone response, with the nearfield responses of the woofer and port plotted below 350Hz and 700Hz, respectively. Once the speaker is driven via its crossover, the upper two woofer modes are suppressed by 15dB and more (fig.3), though the LF driver still seems balanced a couple of dB too high in level compared with the tweeter. The woofer is around 6dB more sensitive than the tweeter, and while it has a basically flat response throughout the midrange and low treble (not shown), its high-frequency output is disturbed by strong breakup modes at 1kHz, 4.8kHz, and 7.1kHz. I suspect that it is this behavior that accounts for AD finding the piano's left-hand register to sound too prominent.įig.2 Audio Note AN-E Lexus Signature, cumulative spectral-decay plot calculated from the output of an accelerometer fastened to the cabinet's side panel 8" from the top (MLS driving voltage to speaker, 7.55V measurement bandwidth, 2kHz).īecause the Audio Note has an external crossover, I could examine the behavior of the unfiltered drive-units. The AN-E's high sensitivity will reduce the audibility of this resonant behavior-for a given input signal, the Audio Note will put out a significantly higher sound-pressure level than a conventional speaker-but it will introduce audible coloration, in my opinion. These last two modes were also present on the front baffle and the rear panel, while another strong mode was present at 550Hz lower down on the sidewall. A prominent ridge of resonant energy can be seen at 484Hz, with two other strong modes present at 230Hz and 270Hz. Fig.2, for example, is a cumulative spectral-decay plot calculated from the accelerometer's output when it was fastened to the enclosure's sidewall 8" from the top. ![]() The Audio Note's plywood cabinet was very lively when subjected to the "knuckle-rap" tests: investigating the panels' vibrational behavior with a plastic-tape accelerometer revealed several major resonances. The impedance traces are broken by some slight discontinuities between 200Hz and 900Hz, though they'll be hard to see at the scale this graph is printed in the magazine. Even so, I don't think the speaker will make significant demands for current on the partnering amplifier, which, in combination with the high sensitivity, makes it very suitable for use with flea-powered single-ended amplifiers.įig.1 Audio Note AN-E Lexus Signature, electrical impedance (solid) and phase (dashed). The impedance remains above 6 ohms for most of the audioband (fig.1), though it does drop to 3.9 ohms in the lower midrange and to 4.8 ohms in the upper treble, and there is a combination of 6.2 ohms magnitude and –40° electrical phase angle at 112Hz. The Audio Note AN-E Lexus Signature was one of the more sensitive dynamic speakers I have measured, at an estimated 92.5dB(B)/2.83V/m, though it should be noted that this is well below the specified 98dB figure. ![]()
0 Comments
Leave a Reply. |