Reviewed on: SoundStage! Solo, March 2020
I measured the Monitor II A.N.C. headphones using professional-grade equipment: a G.R.A.S. Model 43AG ear/cheek simulator/RA0402 ear simulator with the KB5000 and KB5001 anthropomorphic simulated pinnae, 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. For measurements in Bluetooth mode, I used an MEE Audio Connect Bluetooth transmitter to get the signal to the headphones. 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 Monitor II A.N.C.s’ frequency response measured in what I expect will be the headphones’ most-used mode: Bluetooth with noise canceling on, with the stock Marshall EQ setting. This is a fairly weird response, lacking in bass energy and with what appears to be a couple dB excess energy in the upper mids and lower treble. This is the best match between left and right channels I was able to achieve; it’s possible that slightly different acoustics inside the earpieces resulted in the mismatch, or it could be that the Monitor II A.N.C.s just have a fussy fit on my ear/cheek simulator.
Here you can see the difference in response when the Monitor II A.N.C.s are used in Bluetooth mode with NC on and off, and in wired mode with the power off and power on with NC on, all with the stock Marshall EQ mode. The most “normal” of all these measurements is in wired mode with NC on; it shows a reasonable balance between bass and upper midrange/lower treble. Note the orange trace, which is the response you’ll get with the headphones cabled and power off. This is the “native” acoustical response of the driver and its surrounding components (earcup, earpads, and baffle). Its strange appearance suggests that Marshall didn’t put much work into the acoustics, and instead relied on digital signal processing to tune the headphones -- an increasingly common practice.
This chart shows the effects of two of the EQ modes: Rock and Hip-Hop. Note that the effects of these EQ settings are fairly modest in terms of dBs plus or minus, but they’re enough to make a significant subjective difference in the sound.
This graph shows the response of the Monitor II A.N.C.s in Marshall EQ mode compared with similar designs (the DALI IO-6, NAD Viso NP70, and the AKG N700NC headphones, which conform closely to the Harman curve). All are shown in Bluetooth mode with noise canceling on. Note that the Monitor II A.N.C.s, in the Marshall EQ mode, have clearly the least bass and the strongest output in the upper midrange and lower treble around 2 to 4kHz. There’s no way this setting is going to sound normal -- I can’t fathom why Marshall made this their default setting.
The Monitor II A.N.C.s’ spectral decay (waterfall) chart -- measured with a wired connection because of Bluetooth’s latency, and in active mode with NC on -- looks pretty clean, indicating there are no significant resonances.
The Monitor II A.N.C.s’ distortion is measured here with a wired connection with NC on, so this incorporates any distortion added by the internal amps and the noise-canceling circuitry. The distortion is a little on the high side in the bass, although it’s only 2 to 3% at the loud listening level of 90dBA. At the crazy-loud level of 100dBA, it starts to get into the 8 to 9% range. It’s higher below 40Hz, but with most music (EDM and hip-hop perhaps excepted), there’s not much content below 40Hz, and distortion seemed low when I listened to hip-hop (although at a more reasonable volume).
In this chart, the external noise level is 85dB SPL, and numbers below that indicate the degree of attenuation of outside sounds. The Monitor II A.N.C.s’ active noise canceling at its maximum setting is pretty good, with 10 to 20dB of noise rejection between 100 and 500Hz -- not Bose-class, but clearly much better than the DALI IO-6 headphones also shown here.
The Monitor II A.N.C.s’ impedance magnitude measurement is dead flat at 33 ohms in passive mode, and almost dead flat at 19 ohms in active mode. Phase in both modes is also nearly flat.
Bluetooth latency of the Monitor II A.N.C. headphones used with the MEE Audio Connect transmitter was 233ms. Sensitivity of the Monitor II A.N.C.s in passive mode, measured between 300Hz and 3kHz using a 1mW signal calculated for the rated 32 ohms impedance, is 103.9dB, so if the batteries run down and you have to use a wired connection, they’ll play loud, although you can see from the frequency-response chart that they won’t have much bass.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, March 2020
I measured the TWS6 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 an M-Audio Mobile Pre USB interface and TrueRTA spectrum analyzer software. I used an MEE Audio Connect Bluetooth transmitter to get signals into the earphones. All measurements were made using the small silicone eartips with the medium-size silicone “wings,” as these fit the ear/cheek simulator best. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. I don’t include a spectral decay chart here because while I was able to get a measurement (which I can’t usually do with true wireless headphones due to latency), it was somewhat idiosyncratic and I can’t be sure the idiosyncrasies aren’t due to the Bluetooth connection. If you’d like to learn more about what our measurements mean, click here.
The above chart shows the TWS6 earphones’ frequency response. I’ve never seen a curve quite like this before. Typically, we’d see a big response bump of about 10dB around 3kHz, but here we see just a tiny, narrow bump of about 3dB. However, there’s a generally rising response above 500Hz, and not much low bass to balance it out, which is likely why these earphones’ sound didn’t have much body.
The impulse response (from which the Clio analyzer derives the frequency response) shows typical latency at 319ms, which is high enough to produce significant lip-sync problems when watching video, but that will depend on the source device.
This chart shows the TWS6 earphones’ right-channel response compared with two other true wireless earphones, as well as the AKG N5005s, which, when used with their reference filters, are the earphones said to best conform to the Harman curve, the response that research shows delivers what most listeners consider the most natural sound. You can see how unusual the TWS6es’ response is; the response of the EarFun Frees is more what I’d consider a “normal” response for relatively inexpensive earphones. The response of the Sennheiser Momentum True Wireless earphones does have certain similarities to the TWS6es’ response, but in my experience, those earphones needed a lot of EQ tweaking to sound good.
Here’s the TWS6es’ total harmonic distortion measured at levels of 90dBA and 99.5dBA, both determined with pink noise. (I wasn’t able to get them to play at 100dBA, my usual measurement standard, with pink noise.) This is a fairly normal result; although the distortion gets up into the 2 to 3% range at 99.5dBA, transducer distortion isn’t all that audible. There is a huge spike in distortion below 23Hz. Because music has almost no content at such a low frequency, I wouldn’t expect this to create audible problems, but I did note bass distortion in my listening.
This chart is produced by playing 85dB SPL pink noise through four speakers plus a subwoofer, “flatlining” the response at the ear/cheek simulator at 85dB, then inserting the earphones and observing the reduction in noise reaching the simulator’s internal microphone. As you can see, the TWS6es’ noise isolation is, like that of some of the best true wireless earphones, excellent if you get a good fit. It’s comparable with what I measured from the Amazon Echo Buds -- and those have active noise canceling!
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, February 2020
I measured the HA-FW01 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 an M-Audio Mobile Pre USB interface and TrueRTA spectrum-analyzer software. The earphones were amplified using a Musical Fidelity V-CAN. Except as noted, all measurements were made using medium-sized, single-flange silicone eartips, as these fit the ear/cheek simulator best. 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 HA-FW01s’ frequency response. Historically speaking, this is pretty much a textbook response -- i.e., one that’s been common in earphones going back at least as long as I’ve been measuring them (about eight years) and probably long before. I couldn’t count the number of times I’ve seen that big, broad bump below 800Hz and the strong emphasis around 3 to 5kHz (which corresponds to the canal resonance of the ear simulator).
This chart shows how the HA-FW01s’ tonal balance changes when they’re used with a high-impedance (75 ohms) source, such as a cheap laptop, some cheap professional headphone amps, or some exotic tube amps. It’s identical except for a difference of less than 1dB at 20Hz, which no one would notice.
This chart shows the HA-FW01s’ right-channel response compared with a couple of affordable audiophile-oriented earphones, as well as the AKG N5005s, which when used with their reference filter are the earphones said to best conform to the Harman curve, the response that research shows delivers what most listeners consider the most natural sound. Here we can see how a typical earphone response differs from the Harman curve. If you limited the HA-FW01s’ bass/lower-mid bump to below 100Hz, and shifted the upper-mid/lower-treble bump down by 1kHz, you’d have a Harman-curve earphone.
The HA-FW01s’ spectral-decay (waterfall) chart shows substantial resonance below 500Hz, perhaps the reason we thought the sound was a bit bassy. There’s also the slightest sliver of a very well-damped and extremely high-Q resonance at about 4.6kHz, which doesn’t correspond with anything in the frequency-response or distortion charts, but does correspond with a wrinkle in the impedance curve, for what it’s worth.
Here’s the HA-FW01s’ total harmonic distortion measured at levels of 90dBA and 100dBA, both determined with pink noise. This is an outstanding result, among the lowest distortion I’ve measured in a set of earphones. That’s a tough little driver.
This chart is produced by playing 85dB SPL pink noise through four speakers plus a subwoofer, “flatlining” the response at the ear/cheek simulator at 85dB, then inserting the earphones and observing the reduction in noise reaching the simulator’s internal microphone. As you can see, the HA-FW01s’ noise isolation is nothing special, roughly the same as that of the physically similar 1More Quad Driver earphones’ noise isolation, and not as good as seen in the earlobe-filling Campfire and MEE Audio models.
The impedance magnitude of the HA-FW01s is just about dead-flat at 27.5 ohms, and the phase is similarly flat.
Sensitivity of the HA-FW01 earphones, measured between 300Hz and 3kHz, using a 1mW signal calculated for the rated 28 ohms impedance, is 108.9dB, thus the HA-FW01s will deliver plenty of volume from any source device.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, February 2020
I measured the Drop + THX Panda 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; Bluetooth measurements were made using an MEE Audio Connect Bluetooth transmitter. 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 Pandas’ frequency response in wired mode, which gave me the most consistent measurements (wired mode vs. Bluetooth mode shown below). This response is generally in the ballpark of what I measure from good, closed-back headphones, with perhaps a bit less bass than usual.
These measurements, made using white noise with a spectrum analyzer, compare the Pandas’ frequency response in wired and Bluetooth modes. They’re very close, especially considering that some of the observed differences are surely due to the inherent inaccuracy of noise-based measurements.
This chart shows how the Pandas’ 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 effectively no difference.
This chart shows the Pandas’ right-channel response compared with several other good closed-back headphones and with the Audeze LCD-1s, planar-magnetic, open-back headphones that are the same price as the Pandas. Except for having less bass and less energy around 2kHz than the closed-back models, there’s nothing particularly unusual about this response. By the way, the red trace shows the AKG K371 headphones, which conform closely to the so-called “Harman curve.”
The Pandas’ spectral-decay (waterfall) chart shows that these are planar-magnetic headphones, because of the many narrow resonances between 1.5 and 5kHz. However, these are far better damped than in any planar magnetics I can remember measuring. I’m not sure if these would occur for an actual listener; I’m told they’re due to reflections between the large, flat driver and the cheek plate of the G.R.A.S. 43AG.
The total harmonic distortion of the Pandas in wired mode is negligible: only 2% at 20Hz even at dangerously loud listening levels.
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 Pandas is outstanding for passive headphones. Above 500Hz the Pandas clearly deliver superior isolation; positioning of the headphones on the ear/cheek simulator can affect these results, but when you see one model providing 9 to 14dB more isolation at mid and high frequencies, clearly they’re doing something right. I also included a noise-canceling model, the NAD Viso HP70s, so you can see how typical noise-canceling headphones would perform differently on this test.
The impedance magnitude of the Pandas in wired mode is almost dead-flat at 27.5 ohms, and the phase response is similarly flat.
Sensitivity of the Pandas in wired mode, measured between 300Hz and 3kHz, using a 1mW signal calculated for 26-ohms rated impedance, is 97.7dB. That’s somewhat low; you may or may not get satisfying volume if you plug them into a cheap smartphone or an inflight entertainment system.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, February 2020
I measured the Cupid 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 an M-Audio Mobile Pre USB interface and TrueRTA spectrum-analyzer software. The earphones were amplified using a Musical Fidelity V-CAN. Except as noted, all measurements were made using medium-sized, single-flange silicone eartips, as these fit the ear/cheek simulator best. 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 Cupid earphones’ frequency response. There’s a strong bass bump below about 150Hz, and a very strong lower-treble peak between about 2.3 and 4.6kHz. But there’s not a lot of energy in the mid-treble, between about 5 and 10kHz.
This chart shows how the Cupids’ 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. With the high-impedance source, the sound mellows out slightly; the treble is reduced by 1 to 2dB, which in this case would probably be a good thing.
This chart shows the Cupids’ right-channel response compared with a couple of comparably priced audiophile-oriented earphones, as well as the AKG N5005 earphones, which when used with their reference filter are the earphones said to best conform to the Harman curve, the response that research shows delivers what most listeners consider the most natural sound. You can see how “smiley” the Cupids’ response is relative to the others, with substantially boosted bass and lower treble -- or recessed midrange, if you prefer to look at it that way.
The Cupids’ spectral decay (waterfall) chart looks generally pretty clean except for a resonance around 1.4kHz. It’s pretty well-damped, dying out within 5ms, but it does correspond with . . .
. . . the large distortion peak seen in the total harmonic distortion versus output level measurement. Readers who’ve perused my past measurements may have noticed that I tend to pooh-pooh mild distortion of a couple percent in transducers, especially at high listening levels, but here we’re talking about distortion of roughly 5% at the fairly loud listening level of 90dBA, and about 13.5% at the extremely loud level of 100dBA. Gradual rises in distortion below 100Hz at high levels are common in earphones, but I can’t recall having seen large distortion peaks like this in the midrange. Note that I measured normal distortion levels in a different set of earphones and a set of headphones in the same listening session, within a minute or two of measuring these, and I repeated the measurement of the Cupids after checking and resetting the levels, but got the same results. I have to wonder if this is the cause of the midrange “muddiness” we noted, in conjunction with the low output in the midrange relative to the bass and treble.
This chart is produced by playing 85dB SPL pink noise through four speakers plus a subwoofer, “flatlining” the response at the ear/cheek simulator at 85dB, then inserting the earphones and observing the reduction in noise reaching the simulator’s internal microphone. As you can see, the Cupids’ provide an average amount of noise isolation compared with some similar models.
The impedance magnitude of the Cupids is unusual, running almost dead-flat at 15 ohms up to 2.5kHz, then dropping abruptly at higher frequencies, to a low of about 5 ohms at 20Hz. This strikes me as particularly strange because the planar-magnetic driver is said to function as a tweeter, yet all the planar-magnetic drivers I can remember measuring had effectively a resistive (i.e., flat) impedance. The phase also shifts somewhat in this frequency range.
Sensitivity of the Cupids, measured between 300Hz and 3kHz, using a 1mW signal calculated for 16-ohms rated impedance, is 103.9dB, thus the Cupids should deliver pretty good volume from any source device.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, January 2020
I measured the DALI IO-6 headphones using professional-grade equipment: a G.R.A.S. Model 43AG ear/cheek simulator/RA0402 ear simulator with the KB5000 and KB5001 anthropomorphic simulated pinnae, 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. For measurements in Bluetooth mode, I used an MEE Audio Connect Bluetooth transmitter to get the signal to the headphones. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed.
The above chart shows the IO-6es’ frequency response measured in what I expect will be the headphones’ most-used mode: Bluetooth with noise canceling on. This curve is fairly normal in that there’s a modest bass bump below 150Hz, and strong output between 2 and 4kHz corresponding with the primary canal resonance of the average human ear (and the RA0402 ear simulator). What’s unusual is the strength of the peak at about 7.5kHz; we often see a response peak here, but usually it’s about 5dB down from the peak between 2 and 4kHz.
Here you can see the difference in response when the IO-6es are used in Bluetooth mode with NC on and off, and in wired mode with the power off. There’s only a mild difference in bass response when you turn NC on and off, and although it’s not shown here, the “transparency” mode has effectively the same frequency response as the NC off mode. Wired mode has a much stronger peak at 2kHz than any active mode, which means these will sound somewhat bright if used in passive mode.
This graph shows the response of the IO-6es compared with similar headphones (the Beyerdynamic Lagoon ANC, NAD Viso NP70, and the AKG N700NC models, which conform closely to the Harman curve). All are shown in Bluetooth mode with noise canceling on. The IO-6 headphones are in the ballpark with the rest, but have the flattest overall response -- except for that big peak centered at 7.5kHz. That could make them sound a little brighter, and should also give the impression of greater treble detail and “air.”
The IO-6 headphones’ spectral decay (waterfall) chart -- measured with a wired connection because of Bluetooth’s latency, and in passive mode (i.e., power off) -- looks very clean, indicating there are no significant resonances.
The IO-6es’ distortion is measured here with a wired connection in passive mode (power off); the internal amps of the headphones may add some distortion, but my analyzer can’t compensate for Bluetooth’s latency (or even with the roughly 30ms of latency of active wired mode) when doing distortion measurements. The distortion is trivial at 90dBA. At 100dBA, it rises to about 5% at 50Hz, which suggests that if you crank these to extremely loud listening levels, the bass might get a little wooly (but so will your hearing after a few minutes of such abuse).
In this chart, the external noise level is 85dB SPL, and numbers below that indicate the degree of attenuation of outside sounds. The IO-6es’ passive isolation, above about 500Hz, is good, but the noise canceling in “airplane band” below that is modest -- about 5dB on average, which is competitive with the Beyerdynamic Lagoon ANCs but nothing like the noise canceling achieved by the class-leading Bose NC 700s (shown here with NC set to maximum) or the NAD Viso HP70s. If noise canceling is a priority for you -- if you want near-silence when you put on your headphones during a flight -- the IO-6es aren’t your best choice.
The IO-6 headphones’ impedance magnitude measurement is just about dead flat in active mode or passive, averaging 320 ohms in the former and 25 ohms in the latter. Phase in both modes is also nearly flat. This suggests that the sound of the headphones won’t change with the output impedance of the source device.
Bluetooth latency of the IO-6 headphones used with the MEE Audio Connect transmitter was 218ms. This surprises me, as the transmitter and the headphones are both equipped with aptX, and typical aptX latency is around 110ms. So if your video display has low latency, you may notice some lip sync errors when using the IO-6es while watching videos. Sensitivity of the IO-6es in passive mode, measured between 300Hz and 3kHz using a 1mW signal calculated for the rated 25-ohms impedance, is 101.5dB, so if the batteries run down and you have to use a wired connection, they should play fairly loud.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, January 2020
I measured the FS-HAL1 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. The earphones were amplified using a Musical Fidelity V-CAN. Except as noted, all measurements were made using medium-sized, single-flange silicone eartips, as these fit the ear/cheek simulator best. 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 FS-HAL1s’ frequency response, which looks pretty typical for a set of earphones with a well-balanced sound. The peak between 3 and 5kHz is broader than the usual narrow peak centered at about 3kHz. The broad hump below about 800Hz is typical of earphones using dynamic drivers for the bass; it may have a bit of excess upper bass/lower midrange.
This chart shows how the FS-HAL1s’ 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 barely any difference at all below 13kHz, which is a result I’ve seen in perhaps one or two other earphones using balanced armatures.
This chart shows the FS-HAL1s’ right-channel response compared with three other hybrid earphones: the 1More Triple Drivers, the Campfire Audio IOs, and the AKG N5005s, which when used with their reference filter are the earphones said to best conform to the Harman curve, the response that research shows delivers what most listeners consider the most natural sound. The FS-HAL1s are mostly in the ballpark with the 1More and AKG earphone, although the bass-to-treble balance suggests the FS-HAL1s will sound a little mellower.
The FS-HAL1s’ spectral decay (waterfall) chart shows a tiny amount of very well-damped resonance at 4kHz, and a little bit of resonance below 400Hz, but overall, its resonance is comparatively low.
The FS-HAL1s’ distortion is exceptionally low, below 1% even at the extremely loud listening level of 100dBA.
The impedance magnitude of the FS-HAL1s is flatter than that of typical hybrid earphones, running basically flat to 5kHz, and the phase is almost completely flat. This suggests that unlike almost all earphones using balanced-armature drivers, the FS-HAL1s’ sound won’t vary greatly no matter what the output impedance of the source device. It also leads me to believe that the dynamic “woofer” is covering most or all of the midrange as well as the bass.
Sensitivity of the FS-HAL1 earphones, measured between 300Hz and 3kHz, using a 1mW signal calculated for 32 ohms rated impedance, is 108.8dB, thus the FS-HAL1s should deliver satisfying volume from any source device.
. . . Brent Butterworth
brentb@soundstagenetwork.com
Reviewed on: SoundStage! Solo, January 2020
I measured the Rai Penta 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. The earphones were amplified using a Musical Fidelity V-CAN. Except as noted, all measurements were made using medium-sized, single-flange silicone eartips, as these fit the ear/cheek simulator best. 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 Rai Penta earphones’ frequency response, which in terms of the shape of the curve is fairly typical. The peak between 1.5 and 4.5kHz is much broader than the usual narrow peak centered at about 3kHz. The broad hump between about 20Hz and 600Hz is typical of earphones, but has a little more upper-bass/lower-midrange content than I typically see in high-end earphones.
This chart shows how the Rai Pentas’ 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. As I usually see with earphones employing balanced armatures, there’s a change in tonal balance with high-impedance and low-impedance sources; with a high-impedance source, you’ll hear about 1.5dB more bass and about 2dB less treble. That’s a fairly large tilt that will mellow out the sound of the earphones.
This chart shows the Rai Pentas’ right-channel response compared with the Campfire Solaris and the AKG N5005 earphones. The N5005s, when used with their reference filter, are the earphones said to best conform to the Harman curve, the response that research shows delivers what most listeners consider the most natural sound. The Rai Pentas seem to mostly strike a balance between the two other earphones, although they have more upper-bass/lower-midrange output than either.
The Rai Pentas’ spectral decay (waterfall) chart looks very clean above 400Hz, but there’s a lot of resonance below 400Hz. I wonder if this is part of why I perceived the upper bass and lower mids to be overly rich at times, and I wonder if the ports on the dynamic-driver enclosure have anything to do with it.
The Rai Pentas’ distortion is low; we see a rise to about 2% in the range of 500Hz to 1.4kHz, as the balanced armatures take over from the dynamic driver, but it’s only at the extremely loud listening level of 100dBA.
The impedance magnitude of the Rai Pentas is typical of a hybrid earphone design: mostly flat in the bandwidth of the dynamic driver, but fluctuating with frequency as the balanced armatures take over. This is why the tonal balance shifts when a high-output-impedance source device is used. Phase stays fairly flat, though.
Sensitivity of the Rai Penta earphones, measured between 300Hz and 3kHz, using a 1mW signal calculated for 20 ohms rated impedance, is 112.4dB, thus the Rai Pentas will deliver ample volume from any source device.
. . . Brent Butterworth
brentb@soundstagenetwork.com
The following categories containing listings of all product reviews published by the SoundStage! Network since 1995 from all of our online publications. The products are divided into categories and listed in descending order by date. There is no Search function within the listings, but you can search by bringing up the page with the appropriate list and using the "Find" command on your browser. (For Internet Explorer select: Edit > Find on this Page.)