Saturday, 9 April 2022


For the post this week, let's have a look at the 1MORE Quad Driver IEM (~US$150 these days). These have been out for awhile; released in mid-2017 I believe. The specs on these are quite interesting given the asking price. Driver configuration seems complex with single dynamic driver and 3 balanced armature units within the relatively small capsule. The dynamic driver is advertised as being some kind of "diamond-like carbon" (DLC) that covers bass and mids with the balanced armature units filling in at the higher frequencies based on the advertising material.

Furthermore, the headphone also has an integrated volume/playback control as well as a microphone when making calls.

The brand also prides itself on this being the world's first "THX Certified Headphone". I'm not sure exactly what that certification means; presumably some combination of testing to ensure low distortion and frequency response thresholds must be in the mix.

Here's a closer look at the headphones:

The aluminum ear pieces obviously have some weight to them, but not uncomfortable for me when used over an hour or two (I typically don't listen much longer than that with headphones anyway). Total weight of the unit is 21gm. You can see the metal in-line playback/volume smart phone or digital player controller connected to the right ear piece; the microphone is also integrated into this. The weight of that controller isn't heavy enough to be uncomfortable with asymmetrical tugging. The 3.5mm jack is a right-angle connector which is fine for mobile gear although people will have different opinions on this.

While they do insert into the ear canal to be classified as a type of IEM, it's not deep insertion so this should not be too uncomfortable for those who are sensitive.

The non-detachable wire is a translucent copper color, the material is compliant but "springy" thanks to some Kevlar wrapping internally, resisting tangling which is nice. Since cable damage is probably the most common cause of headphone damage, it would have been preferable to have a detachable cable at this price point. The cable is moderately microphonic, but less than the previously examined Etymotic ER-4B. Length of the wire from base of the 3.5mm 90° connector to the earpiece is 120cm (this is quite standard with many mobile-oriented earphones).

Here's a closer look at the earpieces:

Notice the 45° angulation for insertion into the ear canal, ear tips can be switched out for different sizes. Brush aluminum color looks really good with the red highlight. These earbuds will look good walking around town; not bringing attention to themselves while looking elegant.

Interesting artwork for the box, reminiscent of daVinci sketches. A nice assortment of accessories come with these headphones including an airplane adaptor, hard carry pouch with magnetic flap, 3.5mm-to-1/4" adaptor, and a collection of ear tips of different sizes. There are 5 options for the silicone tips and another 3 pairs of foam tips which can be a bit more comfortable and provide more isolation. Note though that there will be some change in sound quality between the silicone and foam tips so make sure to experiment and determine which sounds best for yourself.

Since 1MORE provides more of the rubber/silicone tips, and I use those mostly, for the tests today, let's just stay with the medium sized 13mm tip which works best for me.

Here are the headphones inserted into the miniDSP EARS test fixture (general procedures discussed here and comments here for IEMs):


As usual, let me show you the "big graph" of headphone characteristics to start:

Thus far, I don't have many IEM comparisons but we can look at this in relation to the Etymotic ER-4B from a few weeks back. The frequency response is obviously quite different. Note that with any headphone measurement rig, we have to be careful about the higher frequencies above >3-5kHz due to the presence of canal resonances especially with an artificial system like this. The accentuation >10kHz is nothing I'm concerned about in real-life listening.

What's more relevant when listening to these is the presence of that mid-bass "hump" and the relative midrange dip from 1-3kHz. Compared to the Etymotic ER-4B, clearly the tonality is mid-bass heavy (sub-bass not particularly accentuated), and the midrange around 2kHz is noticeably recessed.

The headphone impedance is around 35Ω which is a good value for modern headphones - not too low and certainly not high. Coupled with the sensitivity of 113dB SPL/V (93dB 1kHz @ 0.1V, 98.5dB/mW into 35Ω impedance - official specs say 99dB/mW), this should not pose a problem for headphone amps whether you're pairing with a smartphone or desktop amp.

The waterfall graph is not as clean as the simple single balanced armature Etymotic. Bass decay is not as smooth, and a -40dB waterfall drop (1kHz level as reference) is not as steep, taking around 4ms from 2kHz and up (as opposed to <2ms with the Etymotic).

One area that is a significant improvement over the Etymotic is the distortion graph in the right-lower quadrant where we can see THD stays below 0.5% from <100Hz and is measured at only 0.1% by 1kHz. I presume this low-distortion characteristic of these headphones must inform in part the THX certification process. 

Using the 1MORE silicone tips, I can tell that noise isolation isn't as good as the Etymotic and this can be shown on the isolation graph:

External noise is blocked starting from around 800Hz with a typical reduction pattern into the higher frequencies. By 5kHz, external noise is attenuated by -30dB. With the Etymotic ER-4B, the value is around -40dB. I would imagine use of the foam tips will improve the isolation characteristic.

With highly sensitive IEM earphones, we don't expect much noise leakage:

As you can see above, the leakage tends to occur with higher frequencies above 1kHz, with a local peak around 5kHz. On average, the measurement mic is picking up 60dB SPL at 1", which works out to 38.5dB SPL at 1-foot away when playing at 100dB SPL. To put this in perspective, the Etymotic ER-4B with their highly isolated triple-flange ear pieces produce only <21dB SPL @ 1', and an open headphone like the Sennheiser HD800 measured 67dB SPL @ 1'. Overall no surprise here. It's unlikely that at normal listening levels, someone sitting nearby would complain about hearing much leakage, and if the leakage is audible, it would be mainly higher frequencies as shown.

Finally, here's the 100Hz bandlimited square wave (calibrated to 95dB SPL @ 1kHz amplitude):

Compared to the Etymotic and its simple single-armature driver, we see more leading edge "roughness" which probably is a reflection of the integration of multiple drivers.


I bought these headphones many moons ago and have been using them over the years (I mentioned them back in the summer of 2017). I mentioned back then that one can get a good amount of bass with these. 

My impression over the years is that these headphones sound "warm" and "smooth" to describe tonality and detail. If anything, they err on the side of being perhaps "too pleasant". That mid-bass hump will add a bit of extra "thump" to the music but this is not head-shaking sub-bass. For example, on the recent Tears For Fears album The Tipping Point (discussed last week), the title track has a clearly synthetic reverse bass hit effect near the beginning which starts as a low rumble that builds. The magnitude of the sub-bass with these headphones doesn't quite capture what you would hear in a room with a good subwoofer although there's more than a hint to the listener that there is some very low bass content down there.

That mid-bass accentuation in concert with the dip around 2kHz can make vocals (especially female vocals) a bit "dull" and overly "warm" to my ears. For those who are very sensitive to sibilance, or those who listen to older albums (like some of the '80s stuff) which sound "thin", this additional "warmth" would be okay. For example the vocals on Cécile McLorin Salvant's most recent album Ghost Song (2022, DR10) could use a little more midrange boost to add excitement when listening with the 1MORE Quad. Regarding the album, it's interesting and more challenging than most in this "female jazz vocal" genre in that it's much more introspective and original than the typical songbook material we're often used to hearing. I think you'll hear mixed reviews from audiophiles.

Resolution sounds reasonably good with these. Details in the music can be appreciated but it's not as clean as something like the Etymotic. Not as "etched" for example with the applause in live recordings (I was watching/listening to the Eagles' Farewell I Tour: Live from Melbourne on these the other night) or the "grain" one hears on something like Neil Young's Barn (eg. grittiness of that distorted guitar on "Canerican"). I suspect this is a combination of the frequency response and waterfall graph suggesting longer decay time.

I find it hard to comment on "soundstage" of IEMs unless one is listening to binaural audio. This is why I've commented previously on demos like the "Virtual Barber Shop" which sounds fine on these headphones but not as convincing as the Etymotic ER-4B which was intended for binaural monitoring.


A closer look at the driver. Notice what looks like a tiny pin-hole vent at the front.

Overall, I still like these headphones and use them routinely when I go out and about town. The microphone works well - at least that's what others tell me when I make calls ;-).

I would say they're a mixed bag. Build quality remains great all these years but the lack of replaceable cables still implies that one has to be careful with not causing damage to the wires. While the metallic shell looks great and feels reassuringly sturdy, I think some listeners might not like the weight and I would not use these when exercising. The package includes many accessories and a good selection of ear tips. BTW, COMPLY has compatible T-600 tips if you prefer.

Sound quality leans toward a mid-bass tonality which I think many would describe as having a "warm" sound; this could either be a blessing or a curse depending on your music and preferences. I certainly cannot complain of harshness and can easily listen to them for hours without discomfort using the appropriate sized ear tips. The handy case, small size, and good looks makes this a nice companion to have when traveling. The company claims that these were sonically tuned by multi-Grammy winner Luca Bignardi (his discography); you can read more about this "tuning" here and see if those thoughts speak to you. Personally, I would have preferred less of that mid-bass.

On my desktop, when listening to these, I will apply EQ to boost the sub-bass a bit with a low shelf, turn down the mid-bass by about 3dB and also bring up the ~2kHz midrange for more "presence". Here are my Roon EQ parameters which sound more natural to me:

As usual, I try not to get too fancy with the EQ. Consider them as basic guidelines from which to further "tune" to one's desire. Since I got these 1MORE Quad Drivers back in 2017, they might or might not reflect current models depending on whether over the years 1MORE has done any tinkering or tuning  of the drivers.

One more thought... This is a good illustration of how much more important frequency response is compared to distortion. As much as the distortion level is lower than the Etymotic, it's just not something noticeable to the point where one would pick that up in the face of obvious frequency response differences. Even for something as intimate as the sound of IEMs.


Looking around over the last while, I'm not seeing much news or interesting articles out there in the audiophile world. Things seem a little slow out there. Maybe supply chain issues and the inflationary environment are delaying the introduction of products or consumer habits? Or maybe that with mature classes of audio devices, the evolutionary process at some point needs to slow down while we wait for truly new advancements in features or levels of performance that make a significant difference.

Regardless, it's not like we're at a loss for high-fidelity products these days at reasonable prices!

Here's hoping you're all doing well, dear audiophiles, as we're well into spring in the Northern Hemisphere. Opportunities to resume a more normal life along with travels abroad I see are gradually opening up as we head into the summer. Assuming fuel prices normalize or course!

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