All loudspeaker measurements are performed independently at the National Research Council of Canada. All measurement data and graphical information displayed below are the property of the SoundStage! Network and Schneider Publishing Inc. Reproduction in any format is not permitted.
Microphone measuring position: tweeter axis
Grille: off
Sensitivity: 85.0dB (averaged 300Hz-3kHz, 2.83V/1m)
Chart A: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: on-axis response
Middle curve: 15 degrees off-axis response
Bottom curve: 30 degrees off-axis response
Chart B: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: 45 degrees off-axis response
Middle curve: 60 degrees off-axis response
Bottom curve: 75 degrees off-axis response
20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Response curve is an average of five measurements: on-axis, 15 degrees left and right off-axis, 15 degrees up and down off-axis
@ 90dB, 50Hz - 10kHz (measured @ 2m)
Top curve: frequency response @ 90dB SPL
Bottom curve: THD+N @ 90dB (50Hz - 10kHz)
Difference @ 90dB from 70dB, 50Hz - 20kHz (measured @ 2m)
Vertical axis: impedance
Horizontal axis: frequency
Vertical axis: phase
Horizontal axis: frequency
All loudspeaker measurements are performed independently at the National Research Council of Canada. All measurement data and graphical information displayed below are the property of the SoundStage! Network and Schneider Publishing Inc. Reproduction in any format is not permitted.
Microphone measuring position: tweeter axis
Grille: off
Sensitivity: 84.0dB (averaged 300Hz-3kHz, 2.83V/1m)
Chart A: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: on-axis response
Middle curve: 15 degrees off-axis response
Bottom curve: 30 degrees off-axis response
Chart B: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: 45 degrees off-axis response
Middle curve: 60 degrees off-axis response
Bottom curve: 75 degrees off-axis response
20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Response curve is an average of five measurements: on-axis, 15 degrees left and right off-axis, 15 degrees up and down off-axis
@ 90dB, 50Hz - 10kHz (measured @ 2m)
Top curve: frequency response @ 90dB SPL
Bottom curve: THD+N @ 90dB (50Hz - 10kHz)
Difference @ 90dB from 70dB, 50Hz - 20kHz (measured @ 2m)
Vertical axis: impedance
Horizontal axis: frequency
Vertical axis: phase
Horizontal axis: frequency
All loudspeaker measurements are performed independently at the National Research Council of Canada. All measurement data and graphical information displayed below are the property of the SoundStage! Network and Schneider Publishing Inc. Reproduction in any format is not permitted.
Microphone measuring position: middle of ribbon
Grille: off
Sensitivity: 83.1dB (averaged 300Hz-3kHz, 2.83V/1m)
Chart A: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: on-axis response
Middle curve: 15 degrees off-axis response
Bottom curve: 30 degrees off-axis response
Chart B: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: 45 degrees off-axis response
Middle curve: 60 degrees off-axis response
Bottom curve: 75 degrees off-axis response
20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Response curve is an average of five measurements: on-axis, 15 degrees left and right off-axis, 15 degrees up and down off-axis
@ 90dB, 50Hz - 10kHz (measured @ 2m)
Top curve: frequency response @ 90dB SPL
Bottom curve: THD+N @ 90dB (50Hz - 10kHz)
Difference @ 90dB from 70dB, 50Hz - 20kHz (measured @ 2m)
Vertical axis: impedance
Horizontal axis: frequency
Vertical axis: phase
Horizontal axis: frequency
All loudspeaker measurements are performed independently at the National Research Council of Canada. All measurement data and graphical information displayed below are the property of the SoundStage! Network and Schneider Publishing Inc. Reproduction in any format is not permitted.
Microphone measuring position: tweeter axis
Grille: off
Sensitivity: 82.5dB (averaged 300Hz-3kHz, 2.83V/1m)
Chart A: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: on-axis response
Middle curve: 15 degrees off-axis response
Bottom curve: 30 degrees off-axis response
Chart B: 20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Top curve: 45 degrees off-axis response
Middle curve: 60 degrees off-axis response
Bottom curve: 75 degrees off-axis response
20Hz - 20kHz (measured @ 2m, plotted @ 1m)
Response curve is an average of five measurements: on-axis, 15 degrees left and right off-axis, 15 degrees up and down off-axis
@ 90dB, 50Hz - 10kHz (measured @ 2m)
Top curve: frequency response @ 90dB SPL
Bottom curve: THD+N @ 90dB (50Hz - 10kHz)
Difference @ 90dB from 70dB, 50Hz - 20kHz (measured @ 2m)
Vertical axis: impedance
Horizontal axis: frequency
Vertical axis: phase
Horizontal axis: frequency
Reviewed on: SoundStage! Solo, October 2018
I measured the Elegias using a G.R.A.S. Model 43AG ear/cheek simulator/RA0402 ear simulator, a Clio 10 FW audio analyzer, a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface, and a Musical Fidelity V-CAN amp, with an Audio-gd NFB-1AMP used for distortion measurements. On the Model 43AG, I used the new KB5000 anthropomorphic simulated pinna for most measurements, and the original KB0065 pinna for certain other measurements, as noted. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed.
The above chart shows the Elegias’ frequency response measured with the new KB5000 and KB5001 anthropomorphic simulated pinnae. This is the best match I was able to achieve between the left and right channels. They match very closely in the midrange, where it counts most. There is a pretty big difference in the bass, which I have to suspect may be due to the way the earpads seal on the face of the ear/cheek simulator (which has to be turned 180 degrees when doing left-ear measurements), but the bass response you see here was very consistent as I moved the headphones around on the simulator, and I usually get a better match than this. Caveats aside, this is an unusual measurement in that the peak in the 3kHz region (which is generally considered to make headphones sound more like speakers in a room) is very mild, only about 4dB above the response at 500Hz; often, the peak is more like 12dB above the 500Hz response.
This chart shows the Elegias’ right-channel frequency response measured with the old KB0065 pinna (which I’ve used for years) and G.R.A.S.’s new KB5000 pinna, which I recently switched to because it more accurately reflects the structure and pliability of the human ear. This is just for sake of comparison with older measurements of mine.
Here you can see how the Elegias’ tonal balance changes when they’re used with a high-impedance source, such as a cheap laptop or some cheap professional headphone amps. It’s a significant effect; the higher-impedance source produces a broad boost that maxes out at 2.6dB at 90Hz, enough to audibly tilt the tonal balance (and in a way I think would likely be to most people’s taste).
This chart shows the Elegias’ right-channel response compared with two other high-end closed-back headphones (the Audeze LCD-XCs and the MrSpeakers Æon Flows with their two-hole white filter installed), as well as the Sony MDR-7506es, a standard fixture in audio production work that generally conform to the “Harman curve,” shown in research by Harman International to be the preferred over-ear headphone response for most listeners. These measurements use the older KB0065 pinna, because that’s the only measurement I have for the LCD-XCs. You can see how unusually flat the Elegias’ response is here.
The Elegias’ spectral decay (waterfall) chart shows a fairly strong resonance at 3.2kHz, which doesn’t seem to correspond to any particular feature of the frequency response. It’s well-damped, though, and nearly gone after about 5ms.
Measured total harmonic distortion (THD) of the Elegias is almost non-existent above 150Hz, and barely breaches 2% in the bass even at the extremely loud level of 100dBA.
In this chart, the external noise level is 85dB SPL, and numbers below that indicate the degree of attenuation of outside sounds. The Elegias’ isolation is very good for a passive closed-back model, generally beating the MrSpeakers Æon Flows and easily beating the smaller NAD Viso HP50s. I threw in the Focal Clear isolation measurement to show the advantage in isolation gained by the closed-back design of the Elegias.
The Elegias’ impedance response is typical for closed-back, dynamic-driver headphones, with the impedance generally hovering close to the rated 35 ohms and rising to 57 ohms peak at the 70Hz system resonance. The phase response is fairly flat for large dynamic-driver headphones.
The sensitivity of the Elegias, measured between 300Hz and 3kHz with the leatherette pads using a 1mW signal calculated for 35 ohms impedance, is 102.9dB. That’s quite high for audiophile-oriented headphones, and it should be enough to get loud volumes from almost any source device.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, April 2023
I measured the Campfire Audio Orbit earphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and an Audiomatica Clio 12 QC audio analyzer. A Reiyin WT-HD06 Bluetooth transmitter was used to send signals from the Clio 12 QC to the earphones. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. Note that I’m unable to do spectral-decay measurements with most Bluetooth earphones because of the latency. If you’d like to learn more about what our measurements mean, click here.
This chart shows the Orbits’ frequency response. See that peak around 5.5 to 6kHz? If you shifted that down by 2.5kHz, this response would look fairly normal. I’m sure that sometime in the last ten years I’ve measured something with a response that looks like this, but I can’t recall what it was or what it sounded like. My guess is that these earphones will sound recessed in the upper midrange, which is where the definition and clarity of human voices happen.
This chart shows the Orbit earphones’ response compared with three true wireless models that have gotten good reviews here. (Models with noise canceling are measured with noise canceling activated.) Note that the KEF Mu3 earphones come pretty close to the Harman curve. It’s easily apparent how much less upper-midrange energy the Orbits have versus the other earphones.
Here’s the THD vs. frequency, measured at 90dBA; I could barely get the Orbits to play any louder. Note that I used discrete sine test tones in one-octave steps rather than my usual sine sweep, because I wasn’t able to find a combination of settings on the Clio analyzer that could compensate for the Bluetooth latency. The distortion is very high at 20Hz, but it’s down to inaudible levels by 40Hz, and very few music recordings have much content below 40Hz. It’s also fairly high at 10kHz, but considering that the first distortion harmonic will be at 20kHz, you won’t hear it.
In this chart, the external noise level is 85dB SPL (the red trace), and the numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. Weirdly, in the simulated pinna of the ear/cheek simulator, I got better isolation with the supplied silicone tips than with the supplied foam tips, but in a real ear, the results may be different. I added the Bose QC Earbuds II to show how a good set of noise-canceling earphones compares.
Latency, measured with the Reiyin transmitter, was typically around 245ms.
Bottom line: The Orbit earphones definitely have a quirky frequency response, which research suggests the majority of listeners probably won’t dig, but Campfire intentionally doesn’t conform to any one target curve, and crafts different sonic profiles for its earphones. It’s up to the listener to decide whether they like this sound.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, March 2023
I measured the Sennheiser Momentum 4 headphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and an Audiomatica Clio 12 QC audio analyzer. A Reiyin WT-HD06 Bluetooth transmitter was used to send signals from the Clio 12 QC to the headphones. A Samsung Galaxy S10 smartphone served as a source for certain measurements. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. If you’d like to learn more about what our measurements mean, click here.
This chart shows the Momentum 4 headphones’ frequency response in Bluetooth mode with noise canceling on full. There’s nothing really out of the ordinary here. The left- and right-channel measurements don’t match all that well; this could be the result of the gating needed to overcome Bluetooth’s latency, but I tried many times to get them to match, and couldn’t.
This chart (done using the Clio’s FFT function with white noise, so it looks somewhat different) shows the difference in response with the noise canceling on and off, Transparency mode, and with a wired connection with power off. Admirably, the noise canceling has no effect on the frequency response. However, Sennheiser doesn’t seem to have put any work into acoustical tuning, because the wired response with power off (which can’t exploit the internal digital signal processing) is a mess—adequate for plugging into an airplane seat and watching old Seinfeld episodes, but not in any case where you care about what the material sounds like.
This chart shows the Momentum 4 headphones’ response compared with a few competitors, all in Bluetooth mode with noise canceling on—except for the AKG K371s, which I’m using as a Harman curve proxy. The Momentum 4s seem a little light in the midrange, but otherwise largely in the ballpark with other good noise-canceling headphones.
The Momentum 4 headphones’ right-channel spectral-decay plot (measured with the wired connection) has a bit of resonance in the bass, but it’s well-damped and basically gone in a few milliseconds.
Here’s the THD vs. frequency, measured using the wired connection at 90dBA and 100dBA (both levels set with pink noise). The distortion gets pretty high in the bass, but only at extremely loud levels, and bass distortion is much less audible because the distortion harmonics are well below the human ear’s range of greatest sensitivity.
In this chart, the external noise level is 85dB SPL (the red trace), and numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. I threw in the Momentum 4s’ Transparency mode, which, strangely, doesn’t seem to let in much sound above 1kHz. The Momentum 4s’ noise canceling isn’t the best, but it’s pretty close to the best.
Note that the transmitter showed it was in aptX Low Latency mode. The headphones are equipped with aptX and aptX Adaptive.
The impedance magnitude, measured in wired mode with power off, measures about 75 to 80 ohms up to 1kHz, and then falls to a minimum of about 52 ohms, with a corresponding electrical phase shift.
Sensitivity with the wired connection, power off, averaged between 300Hz and 3kHz, with a 1mW signal calculated for the rated 80 ohms impedance, is 105.6dB, plenty high enough to get loud levels from any source.
Bottom line: The Momentum 4 headphones’ measured performance looks good, with a pretty safe and sane frequency response and very good noise canceling. The only sore spot is the wackadoodle frequency response in wired/power-off mode.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, January 2023
I measured the Focal Utopia 2022 headphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and a Clio 10 FW audio analyzer. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. The headphones were amplified using a Musical Fidelity V-CAN. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. If you’d like to learn more about what our measurements mean, click here.
The above chart shows the Utopia 2022s’ frequency response. This is fairly ordinary for audiophile headphones, but for two anomalies. First, that unusual little peak at about 1.4kHz, (also seen in the original Utopias), which will likely add a slight emphasis in the upper midrange. Second, the low energy above 8kHz, which isn’t surprising after hearing how the Utopia 2022s seem to damp extreme high-frequency sounds.
This chart shows how the Utopia 2022s’ tonal balance changes when they’re used with a high-impedance (75 ohms) source, such as a cheap laptop or some cheap professional headphone amps, or some tube amps. There’s a substantial bass boost with the high-impedance source—about +3.5dB, centered at about 65Hz—so these may get bassier when used with an amp that has a tube output stage.
This chart shows the Utopia 2022s’ right-channel response compared with the original Utopias and two other well-regarded high-end models: the Meze Elites (used with the supplied Alcantara earpads) and the Sennheiser HD 800 S headphones. You can see how the Meze and Sennheiser models have more energy in the top octave-and-a-half.
Just as with the original Utopias, the Utopia 2022s’ spectral-decay plot looks like the plots I see with planar-magnetic headphones, with a lot of very high-Q resonances between about 1 and 5kHz. That’s weird because planar drivers are flat, but the Utopia 2022s’ drivers are M-shaped. I associate these resonances with a nice sense of space, rather than an audible coloration, but to my knowledge, there’s no science on that—although a famous audio scientist was the one who gave me the idea.
There’s a little bit of distortion in the deep bass with the Utopia 2022s at very high levels, but you’ll never hear it because the distortion harmonics are still well below the most sensitive range of human hearing.
In this chart, the external noise level is 85dB SPL, and numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. The isolation of the Utopia 2022s, like that of most open-back headphones, is negligible. I added the original Utopias so you could see the effects of the changes in the outer grille (it does look like the new one is somewhat more transparent at high frequencies), and the Focal Stellias so you can see how a closed-back model compares.
The Utopia 2022s’ impedance is mostly flat at the rated 80 ohms for about 6.5 octaves, but then it takes a huge swing up to 770 ohms at 52Hz—which shows there’s been a change in the voice coil, because the old model rose only to 655 ohms. There’s also a big phase swing in the bass, corresponding with the impedance peak. This is why these headphones will sound different with high-impedance sources.
Sensitivity of the Utopia 2022s, measured between 300Hz and 3kHz, using a 1mW signal calculated for 80 ohms rated impedance, is 105.6dB—exactly the same as the original model, and no problem for any source device to drive.
Bottom line: There are a couple of unusual frequency-response characteristics with the Utopia 2022s, and definitely not a strong upper-treble response, but the engineering otherwise seems solid, with particular praise for the sensitivity, which is way high for high-end headphones.
. . . Brent Butterworth
brentb@soundstagenetwork.com
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