Reviewed on: SoundStage! Solo, November 2020
I measured the Shure Aonic 5 earphones using laboratory-grade equipment: a G.R.A.S. 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 earphones were amplified using Musical Fidelity V-CAN and Schiit Audio Magnius headphone amps. 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 frequency response of the Aonic 5s (shown with the Balanced filter) is unusually flat for earphones; usually we see a big bump in the bass and a much larger rise around 3kHz. On this test, this result indicates that the Aonic 5s will sound subjectively mid-boosted.
This chart shows the response with the Balanced, Warm, and Bright filters, with the dB resolution doubled to 5dB per major division. Most of the action centers around 3kHz; changing the filter causes a roughly 2.5dB tilt either way in the tonal balance.
This chart shows how the Aonic 5s’ tonal balance (with the Balanced filter) 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 exotic tube amps. This is about as big a difference as I’ve measured on this test, with the high-impedance source reducing bass by about 2dB and treble by 2 to 5dB (and thus effectively boosting the middle of the midrange). I’d guess that with an all-tube (i.e., non-hybrid) amp, the Aonic 5s will sound a lot fuller, although if the amp is noisy, the Aonic 5s’ very high sensitivity will make that noise more audible.
This chart shows the Aonic 5s’ right-channel response with the Balanced filter, compared with several other earphones -- including the AKG N5005s, which are the earphones said to measure closest to the Harman curve, when used with the reference filter attachment. You can see how unusually flat the Aonic 5s are.
The Aonic 5s’ spectral-decay plot is super-clean, with no notable resonances.
Harmonic distortion in the Aonic 5s is trivial even at the crazily high listening level of 100dBA, measured with pink noise.
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 Aonic 5s is outstanding for passive earphones. I also threw in the measurements of the new Bose QC Earbuds so you can see how the Aonic 5s compare with a model that has excellent active noise canceling.
The Aonic 5s’ impedance shows large swings in magnitude and phase above 1kHz, which is why the response varies so much when you switch to a high-impedance source.
Sensitivity of the Aonic 5s, measured between 300Hz and 3kHz, using a 1mW signal calculated for 36 ohms rated impedance, is 116.3dB, so any source device can easily drive them.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, November 2020
I measured the Dan Clark Audio Æon RT Closed headphones using laboratory-grade equipment: a G.R.A.S. 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 and Schiit Morpheus. 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 first chart shows the frequency response with the 1-notch white filter, which was my favorite of the ones supplied. It’s unusual to see such a flat response on this measurement; most headphones show a large (~10dB) peak around 2 or 3kHz, and a smaller peak around 6 or 7kHz. These have just a modest peak between 4 and 5kHz.
This chart shows the effects of the different supplied filters on frequency response, with the vertical (dB) resolution of the chart doubled to 5dB per major division. The effects are mostly subtle: a dB or two here and there. Note that my favorite, the 1-notch white filter, has the most bass response. Note also that the bass response has some of the characteristics of Harman curve bass response, with a lift limited to the range below 100Hz rather than the more typical broad rise below about 500Hz.
This chart shows how the Æon RT Closeds’ 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 exotic tube amps. There’s about a 1dB boost in the bass with the high-impedance source at 20Hz, which would not be noticeable.
This chart shows the Æon RT Closeds’ right-channel response (with the 1-notch white filter) compared with the Æon RT Opens, the Æon 2 Closeds, and a couple of other audiophile headphones in the mid-three-figures price range. (Once again, resolution on the dB scale is doubled here.) What really stands out with the Æon RT Closed headphones is their stronger bass response, and their much weaker response between 2 and 3kHz.
The Æon RT Closeds’ waterfall plot looks very clean -- especially for planar-magnetic headphones, which almost always show a lot of very high-Q, low-amplitude resonances between about 1 and 3kHz.
There’s a little bit of visible harmonic distortion in the Æon RT Closeds’ chart, but even at the crazily high level of 100dBA (measured with pink noise), it maxes out at about 4%, and that’s in the bass so it’s unlikely to be audible (the threshold of audibility of bass distortion is typically quoted at around 10%).
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. As you can see, the isolation of the Æon RT Closed headphones is above average for closed-back headphones. I also included the Æon RT Open headphones so you can see how they perform on this test.
The Æon RT Closeds’ impedance magnitude is dead-flat, right on the rated 12.5 ohms, and the phase is effectively flat.
Sensitivity of the Æon RT Closeds, measured between 300Hz and 3kHz, using a 1mW signal calculated for 12.5 ohms rated impedance, is 85.9dB, which is pretty low, so you’re best off using a decent amp or portable music player with these, rather than a smartphone.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, November 2020
I measured the Philips Fidelio X3 headphones using laboratory-grade equipment: a G.R.A.S. 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 and Schiit Magnius. 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 first chart shows the frequency response. The relatively flat response up to about 1.2kHz is common in open-back audiophile headphones. What’s unusual is that the peak centered at about 3.3kHz is perhaps 1kHz higher in frequency than normal, and the peak at 7kHz is about 8dB higher than I’d expect to see, which suggests a little extra brightness and maybe some lack of energy around 1.5kHz to 3kHz.
This chart shows how the X3s’ 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 exotic tube amps. There’s about a 1dB boost in the bass with the high-impedance source, which would be barely noticeable.
This chart shows the Fidelio X3s’ right-channel response compared with several audiophile headphones, and with the AKG K371s, which closely track the Harman curve. You can easily see how much more energy the Fidelio X3s have between 5 and 10kHz.
Like many large-diaphragm headphones, the Fidelio X3s show many very high-Q, low-magnitude resonances between 1 and 2kHz, which likely represent reflections between the diaphragm and the plate and pinna of the ear/cheek simulator.
Harmonic distortion in the Fidelio X3s is high in the bass frequencies. At the loud level of 90dBA, it’s probably not high enough to notice, but considering that the generally accepted level of distortion audibility in subwoofers is about 10% THD, you might notice some bass distortion at 100dBA -- although that’s a crazily loud listening level.
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 Fidelio X3s is comparable to that of other large, open-back audiophile headphones. I added the Dan Clark Æon 2 Closed headphones so you can see how an audiophile closed-back model performs on this test.
The Fidelio X3s’ impedance magnitude is typical for a dynamic-driver headphone, running about 33 to 34 ohms through most of the audio range, with the expected low-frequency impedance bump at about 90Hz. Impedance phase angle is mostly flat, swinging mildly more inductive in the treble.
Sensitivity of the Fidelio X3s, measured between 300Hz and 3kHz, using a 1mW signal calculated for 30 ohms rated impedance, is 96.2dB, which is a little low, so a smartphone or tablet with a weak internal headphone amp might not be able to get them really cranking.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, October 2020
I measured the Technics EAH-TZ700 earphones using laboratory-grade equipment: a G.R.A.S. 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 and a Schiit Magnius. 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 frequency response of the EAH-TZ700s is pretty standard for dynamic earphones. At a glance, the only thing even slightly unusual is that the bass output is proportionately high relative to the upper-midrange and treble peaks; I’ve seen this in a lot of mass-market models, but it’s not as common in earphones targeted at audiophiles.
This chart shows how the EAH-TZ700s’ 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 exotic tube amps. There’s no difference, so the tonal balance of the earphones won’t change when you change source devices, provided the response of the source device is flat.
This chart shows the EAH-TZ700s’ right-channel response compared with several other earphones -- including the AKG N5005s, which are the earphones said to measure closest to the Harman curve, when used with the reference filter attachment. As you can see, the norm seems to be a little more treble and a little more bass. You can also note in the AKG’s curve the reduced response between 100 and 300Hz, which is characteristic of the Harman curve.
The EAH-TZ700s’ spectral decay plot shows no significant resonances.
Harmonic distortion in the EAH-TZ700s is insignificant even at the crazily high listening level of 100dBA, measured with pink noise.
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 EAH-TZ700s is quite good for passive earphones. I also threw in the measurements of Ultimate Ears UE5 earphones (which were custom-molded to my G.R.A.S. ear/cheek simulator) and the new Bose QC earbuds so you can see how a good universal-fit model like the EAH-TZ700 compares with them.
The EAH-TZ700s’ impedance magnitude is flat at 36 ohms (which is why its response doesn’t vary with the source impedance), and the impedance phase angle is also quite flat.
Sensitivity of the EAH-TZ700s, measured between 300Hz and 3kHz, using a 1mW signal calculated for 37 ohms rated impedance, is 106.7dB, so any source device can easily drive them.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, October 2020
I measured the Beyerdynamic T5 headphones using laboratory-grade equipment: a G.R.A.S. 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 and Schiit Magnius. 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 first chart shows the frequency response. This is a little unusual in that there is the sharp rise in the bass characteristic of Harman curve headphones -- although at a somewhat higher frequency of about 300Hz, rather than 200Hz. Yet there isn’t the roughly 10dB rise in treble around 3kHz that Harman curve headphones would have.
This chart shows how the T5s’ 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 exotic tube amps. There’s about a 1dB boost in the treble with the high-impedance source.
This chart shows the T5s’ right-channel response compared with several planar-magnetic headphones -- including the Dan Clark Audio Æon 2 Closeds, which are the planar headphones I’ve found to measure closest to the Harman curve, when they are used with the optional perforated earpads. The T5s’ response shows more of a bass boost than any of the other headphones shown here, but with less energy between 2 and 8kHz than the Æon 2 Closeds and the Audeze LCD-2 Closed Backs. This suggests the T5s would sound dull . . . but they don’t, at least not to me.
The T5s’ spectral decay plot shows a little more resonance in the bass than you’d probably see with a planar-magnetic model, but not enough to be sonically troublesome.
Harmonic distortion in the T5s is relatively high below 100Hz, although above 30Hz, it mostly stays below 2% at 90dBA (which is a very loud listening level) and 5% at 100dBA (a crazily loud listening level). For reference, the generally accepted threshold for audibility of distortion at these frequencies is about 10%, because the harmonics are all at low frequencies where the ear isn’t very sensitive.
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 T5s is comparable to that of other large, closed-back audiophile headphones.
The T5s’ impedance magnitude is fairly flat, averaging about 40 ohms and swinging between 34 and 44 ohms. Impedance phase angle is also quite flat.
Sensitivity of the T5s, measured between 300Hz and 3kHz, using a 1mW signal calculated for 32 ohms rated impedance, is 102.0dB, so pretty much any source device can easily drive them.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, September 2020
I measured the HEDDphones using laboratory-grade equipment: a G.R.A.S. 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 and an Audio-gd NFB1-AMP. 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 first chart shows the frequency response. Considering that this is the first application of a full-range AMT driver to headphones, the response looks surprisingly normal, much like what I expect to see from open-back planar-magnetic headphones. The only thing that grabs my eye is the roughly +2dB plateau between 50 and 300Hz, which corresponds with my notes that there’s a little too much energy in the 200Hz region.
This chart shows how the HEDDphones’ 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 exotic tube amps. There’s no significant difference, so the tonal balance of the HEDDphones won’t vary when you change amplifiers, unless of course the amplifier’s tonal balance varies.
This chart shows the HEDDphones’ right-channel response compared with several planar-magnetic headphones -- including the Dan Clark Audio Æon 2 Closeds, which are the planar headphones I’ve found to measure closest to the Harman curve, when they are used with the optional perforated earpads. The HEDDphones’ response is generally similar to that of the planar models, except for that elevated region between 50 and 200Hz; note that the Æon 2 Closeds have more bass at 100Hz, but just as they would in a Harman curve model, the output drops sharply by 200Hz. The HEDDphones also have a bit of an energy spike around 1kHz, of which I’ll say more shortly.
The HEDDphones’ spectral-decay plot shows a lot of hash, or very high-Q resonances or reflections, between 2 and 3kHz; I see this result in most planar-magnetic headphones, but here the reflections/resonances are better-damped, probably because the ribbon is pleated rather than flat. However, there’s a roughly 1/3-octave-wide resonant spike centered just above 1kHz, which corresponds with the spike I measured in the right-channel frequency response. I didn’t notice it in my listening, but it should be audible; perhaps I just didn’t find the right test track.
Distortion in the HEDDphones is low, running at or below 1% through almost the entire audio range at both of the testing levels I use; the distortion might look slightly higher in the 90dBA (green) trace than in the 100dBA trace, but that’s because the lower test signal level at 90dBA makes that measurement more susceptible to noise.
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 HEDDphones is comparable to that of open-back planar-magnetic headphones. I threw in the Dan Clark Audio Æon 2 Closeds so you could see how a high-end closed-back model performs on this test.
The HEDDphones’ impedance magnitude is just about dead-flat at 43.5 ohms, and its phase curve is also quite flat.
Sensitivity of the HEDDphones, measured between 300Hz and 3kHz, using a 1mW signal calculated for 42 ohms rated impedance, is 86.8dB, which indicates you’ll need to drive these with an external amp or DAC-amp, or a high-quality portable music player.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, September 2020
I measured the EAH-AZ70W earphones using laboratory-grade equipment: a G.R.A.S. 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. An Mpow BH259A Bluetooth transmitter was used to send signals from the Clio 10 FW to the earphones. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. Note that because of the latency introduced by Bluetooth, I wasn’t able to do a spectral decay measurement, and of course my usual impedance and sensitivity measurements are irrelevant for wireless earphones. If you’d like to learn more about what our measurements mean, click here.
The above chart shows the EAH-AZ70Ws’ frequency response measured with the RA0402 ear simulator, with noise canceling on. This is a somewhat unusual curve, but it’s not crazy-unusual. You can still see the bass bump and roughly 2kHz peak that we see in most good-sounding earphones; what’s unusual is that extra amount of energy between about 600Hz and 1.2kHz, and the peak at roughly 9kHz, rather than the more common 6 or 7kHz. So these earphones are likely to sound tonally balanced, but with some mild colorations in the midrange.
The impulse response shows that the latency with the Mpow BH259A is 283ms. This is fairly standard for true wireless earphones (few of which have aptX Low Latency or aptX Adaptive), and it means you may see lip-sync errors when you watch videos. It’s probably safest to use these for music and podcasts if lip-sync errors annoy you greatly.
This chart shows the EAH-AZ70Ws’ right-channel response compared with other true wireless earphones (Sennheiser Momentum True Wirelesses and 1More E1026BT-I Stylishes), as well as with the AKG N5005s, the earphones said to best reflect the Harman curve. The EAH-AZ70Ws’ response might be considered a cubist interpretation of the Harman curve; unusual as its angular trace looks, it’s more in keeping with audio norms than most true wireless earphones are.
Because of the latency of the Bluetooth connection, I could not use Clio’s sine sweep function to measure total harmonic distortion (THD) versus frequency, so I did discrete THD measurements of sine tones in one-octave steps. Distortion is low at most frequencies and levels, except for an unusual peak at 1kHz, which reaches about 3.2% THD at 100dBA (measured with pink noise). This could be marginally audible, but it’s at such a loud level that your ears would probably be hurting anyway.
This chart shows the EAH-AZ70Ws’ isolation versus three other earphones with active noise canceling: the Apple AirPods Pros, 1More Dual Driver ANC Pros, and Bose QC30s. (The Apple model is a true wireless design, while the 1More and Bose models are neckband-style Bluetooth earphones.) The EAH-AZ70Ws have the best noise canceling I’ve measured in a true wireless design. The 1More Dual Driver ANC Pros beat them by about 5dB below 150Hz, and the Bose QC20 wired noise-canceling earphones (not shown) roughly equal the performance of the EAH-AZ70Ws, but otherwise, the Technics model blows all other earphones I’ve measured out of the water on this test -- especially in the band between 100 and 300Hz, which is where the low thrumming sound of engine noise inside a jet airliner cabin resides.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, August 2020
I measured the DT 770 Studio headphones using laboratory-grade equipment: a G.R.A.S. 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 and an Audio-gd NFB1-AMP. 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 frequency response. This curve is pretty standard; fill in that upper bass dip around 200Hz and reduce the energy between 4kHz and 9kHz by a couple dB, and you’d have a “by-the-book” curve.
This chart shows how the DT 770 Studios’ 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 exotic tube amps. The only difference with the high-impedance source is a boost of about 1dB in the bass, so it’s unlikely your choice of headphone amp will affect the headphones’ tonal balance.
This chart shows the DT 770 Studios’ right-channel response compared with several open-back planar-magnetic headphones -- including the AKG K371s, which are said to be within ±1dB of the Harman curve. This is a very straightforward voicing, so it’s highly unlikely anyone will find these headphones to sound weird or unnatural.
The DT 770 Studios’ spectral-decay plot looks pretty clean, except for a resonance centered at about 200Hz, but after just one cycle (5ms) at that frequency, the resonance is already down to -30dB, so it shouldn’t be troublesome.
Distortion in the DT 770 Studios is fairly high in the bass, even when measured with the powerful Audio-gd NFB1-AMP. At 90dBA (measured with pink noise), it breaks 5% at 30Hz, and at 100dBA, it hits 14% at the same frequency. Note, though, that bass distortion isn’t as audible because the harmonics it produces are at low frequencies and your ears are not so sensitive there; the generally accepted audibility threshold for subwoofer distortion is 10%.
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 DT 770 Studios is comparable to that of similarly sized closed-back headphones. I added the Sony WH-1000MX4s so you could see how headphones with noise canceling perform in this test.
The DT 770 Studios’ impedance magnitude and phase curves are fairly flat, with the magnitude averaging about 100Hz.
Sensitivity of the DT 770 Studios, measured between 300Hz and 3kHz, using a 1mW signal calculated for 80 ohms rated impedance, is 95.8dB, which means you’re best off driving these with an external amp or DAC-amp, or a high-quality portable music player.
. . . Brent Butterworth
brentb@soundstagenetwork.com
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