Gramophone Dreams #13: Audeze The King & Focal Elear Measurements

John Atkinson wrote about the King in January 2017 (Vol.40 No.1):

Toward the end of my time auditioning Audeze's superb-sounding LCD-4 headphones, which I reviewed in the July 2016 issue, I briefly tried a sample of Audeze's new The King headphone amplifier (serial no. K3301003, footnote 1). Herb Reichert had expressed interest in reviewing the King, and before I drove it over to his Bed-Stuy bothy, I examined its test-bench performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"), using unbalanced signals. (Though a pair of XLR jacks is available for input as well as a pair of RCAs, only the hot phase of the King's XLR input is active; the negative phase is connected to ground with a 22k ohm resistor.)

The King's headphone outputs preserved absolute polarity (ie, were non-inverting), and its maximum gain was 14.3dB. With the volume control set to its maximum, a 1kHz input signal at 370mV lit the "100dB SPL" LED on the front-panel meter. The input impedance of the unbalanced RCA jacks was 23.4k ohms at 20Hz and 1kHz, dropping slightly to 19.2k ohms at 20kHz. The input impedance at the XLR jacks was twice those figures, but that means that the impedance of the XLRs' hot phase is the same as that at the RCAs. The output impedance was very low, at 0.6 ohm across the audioband. (The specified figure is 0.3 ohm; my measurement includes the contribution of 1.5m of interconnect.)

Fig.1 Audeze The King, frequency response with volume control set to 12 o'clock (left channel blue, right red) at 1V into 100k ohms (0.5dB/vertical div.).

With its volume control set to maximum, the King's frequency response was flat to 200kHz. However, when I turned the volume knob down to 12 o'clock, while the right channel's response remained unchanged (fig.1, red trace), the left channel's ultrasonic response rolled off by 1.4dB at 200kHz (blue). The channel separation at 1kHz was good, at >90dB in both directions, but the R–L crosstalk rose by 20dB at 20kHz. (The L–R separation was still >90dB at that frequency.)

Fig.2 Audeze The King, spectrum of 1kHz sinewave, DC–1kHz, at 1V into 300 ohms (left channel blue, right red) (linear frequency scale).

The wideband, unweighted signal/noise ratio, taken with the input shorted to ground but the volume control at its maximum—the worst case—was disappointing, at 53.9dB in the left channel and 61.3dB in the right, ref. 1V. A-weighting improved these ratios to 72.7 and 77dB, respectively, but spectral analysis of the King's low-frequency noise floor (fig.2) showed both that the level of random noise was higher in the left channel, and that equal levels of power-supply–related spuriae were present in both channels. This behavior was not changed by experimenting with the ground connection between the analyzer and the headphone amplifier.

Fig.3 Audeze The King, THD+N (%) vs 1kHz output voltage into 30 ohms.

Audeze specifies the King's maximum output as 6W into 20 ohms, which is equivalent to a maximum voltage of just under 11V. Fig.3 plots the King's THD+noise performance against output voltage—you can see that it does indeed clip at 11V into my 30 ohm load (with clipping defined as when the THD+N reaches 1%). The red Overload LED on the front panel illuminated at 10V. The downward slope of the trace in this graph indicates that actual distortion lies below the noise floor until 5V into this load, and that distortion at that level is low, at 0.01%. Plotting the percentage of THD+N against frequency at this level (not shown) revealed that the THD+N doesn't increase at high frequencies.

Fig.4 Audeze The King, spectrum of 50Hz sinewave, DC–1kHz, at 2V into 300 ohms (left channel blue, right red; linear frequency scale).

Fig.5 Audeze The King, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 2V into 300 ohms (left channel blue, right red; linear frequency scale).

The King is a low-distortion design: fig.4 reveals that the only distortion harmonic present is the subjectively innocuous second, at close to –90dB (0.003%). However, this graph also shows the random noise and power-supply components mentioned above, as does the spectral analysis of the King's output as it reproduced an equal mix of 19 and 20kHz tones (fig.5). Actual intermodulation distortion is very low, but fig.5 also shows some modulation of the noise floor, which I couldn't eliminate by experimenting with grounding. I wondered if the Audeze amplifier was picking up some RF interference. I'd replaced the CFC lightbulbs in the test lab with LED equivalents because CFCs are notorious for emitting RF, but repeating the testing with the lights off didn't improve the King's behavior.

There are lots of things to admire in the measured performance of Audeze's King, including the high dynamic range—HR described the King as playing music with the authority of an absolute ruler—and the low levels of harmonic and intermodulation distortion. But I was bothered by the character of the noise floor, even if I could hear no problems in this area.—John Atkinson

Footnote 1: The King costs $3995.

dalethorn's picture

I ordered the Elear from Todd the Vinyl Junkie. Nice friendly guy BTW. I wanted the Utopia, but at this point I decided I'd try the Elear first, on the premise that I'd be sharing my experience with at least a few people, whereas with the Utopia I figured I'd be all alone. If the Elear isn't convincing enough, I'll send it back for the Utopia, and that's what I'd like to read more of on the subject - i.e. people who bought the Elear and then decided they needed the better (or more neutral?) Utopia, and how that worked out for them.

Staxguy's picture

Um no. Not really.

What's wrong with the AKG 812 and Stax 009?

What's wrong with the Sennheiser 800?

lo fi's picture

I lurv cans and agree that they're going off like a cracker on Guy Fawkes night. Cans is where it's at in hi fi at the minute, and they are drawing a much needed younger demographic to it. That said, the rapidly escalating prices for each new flagship headphone release runs the risk of blocking their entry.

cgh's picture

I agree lo-fi. I own one of the first pairs of LCD-2 (driven by Auralic). I love them. Audeze pulled a VPI. Instead of thinking about their line they flooded the market with too many little ideas that didn't differentiate themselves, but they tried to differentiate greatly with price. Listening to my LCD-2s compared to LCD-4s and pondering that the differences cost $3000 doesn't make sense. The price should have a footnote that says "if we had only known in the beginning that we could have charged soooo much more". So much for economies of scale.

xtinct1's picture

I totally disagree. Headphones are unnatural compared to speakers. Simply put the image is always in your head unless you do binaural recordings. Headphones will never impact like speakers. The bass is always focused in your ears and thus there is no visceral impact on the body. Listening to speakers with your eyes closed and you can literally be fooled into thinking your transported into the environment of the performance. Although I respect headphones for their clarity as the music is focused directly to your ears; but even that is somewhat unnatural as there needs to be some sense of sound dissipation and reverberation as one would get in a live event. I am sorry for the rant but I am annoyed by so many comments stating headphones are a better way to listen to music. They simply aren't. And if you don't have the discipline to listen to music without being distracted, then you shouldn't spend your time and money on this hobby.

jasonmith's picture

These are very good when we stay on bed using organic bedding and listening song from this. It's so cool.