The NS-U1 is pretty sensitive. At low listening levels I can hear the AK100’s hiss above my music. The Ultrasone IQ and Shure SE846 bring more of that to the front, but not inordinately more. That said, I pump up my iPhone 4S sometimes to about 40% while listening in my quiet photography studio. Surprise surprise. Sensitive to hiss but mildly insensitive to voltage.
With all its switches turned off, NS-U1 is bassy, powerful, and casts a wide, if not really detailed 3D sound stage. You’ll get music popping up all around you, from shoulder to shoulder, and if fed the right cues, beating between your shoulders. Stere separation is good. Bass throbs in right from the bottom, but keeps a tidy amount of channel separation, which hovers in each channel above the shoulders with very little bleed toward the neck. I find it non-fatiguing for trance music. Mids ooze out from the bass, almost without transition lines- not in the same way mid-smooth multi-armature earphones like Campfire Audio’s Andromeda does, and certainly not with the same level of detail as the Noble Audio K10. It’s an ungoverned escape where bass touches the mids the entire way up. Z-axis bass depth is better than I could have hoped, but 3D detail along that axis is indistinct. Vocals are warm, slightly forward, but overall, mids are neither liquid nor are they hot. In effect, there is a mild U-shape in there, where lower mids fold into bass and higher mids run forward, pushing sound pressure well into the high range. If there’s a high-range roll off, it’s mostly hidden by that active and clear upper midrange. If you like cymbals, high hats, and percussion edges, the NS-U1 renders them clearly and sibilance free.
The NS-U1is clearer and more coherent than the Future Sonics G10. Stereo width and clarity are a level, or two, ahead of the G10. The NS-U1’s bass isn’t as hot, and the balance from top to bottom is more linear, if slightly U-shaped. The NS-U1 gets by my aversion to throbbing bass because of its active upper midrange, which counters some the thunder down below.
And then, like stirring a lump of flour into a soup, switching on NatroSound, thickens and blends everything.
Bass, which used to hover just inside each shoulder, goes into full subwoofer mode, congealing suddenly in the centre of the skull. Effectively it sounds even bigger, even more forceful, and it throbs even more. It loses some texture detail. Of course, if you use the attenuator cable, you can control how much NatroSound gets into your music. Since the attenuator cable that came with my NS-U1 moves the balance farther to the right earphone, I eschew its use for the digital cable, which turn NatroSound to max. What I can tell about the attenuator cable is that it controls how much channel information is shared between the two earphones is extremely well. Scroll it up a bit and you’ll barely hear the difference. Go about halfway up and you have a good sharing of channel information. All the way up and THROB!
Maximized, midrange the z-axis remains deep, but because more stereo information is now passed between channels, you feel further inside the music. Not inside like you do in an earphone like Andromeda which carves out a deep 3D niche, but inside as in, the music is coming at you from all around, even from a small sliver of space behind your shoulders. It’s totally immersive. And while bass dominates even more so than normal, upper mids remain strong. Cymbals lose some edge, but they gain a greater X and Z axis footprint. Intriguing.
When I first tried the NS-U1, I was confused. Not only did the sound suddenly get too big, I was sure that it was a gimmick. As it turns out, I just needed more time. Bass certainly throbs out, and dominates the scene, but despite its massive sound pressure, sharing channel information between earphones really does sound natural. And high mids and highs don’t give up when you flip the NS switch. They still shimmer up there, outside the ears, but they contend with an anchored and perceptively stronger bass.
I should add LEAR were clever to advertise the NS-U1 as good for movie watching. That bass really really punches, and especially when shifted to NS mode, is perfect for action movies. Think Ender’s Game rather than 2001: A Space Odyssey. Centring the bass warms up vocals, and simulates a sub woofer. Well recommended.
Lear have uploaded the following demonstration video: https://www.youtube.com/watch?v=wiZ7A6uvNG4&feature=youtu.be
And it is a pretty good approximation of what happens when you flip the switch.
Perhaps thanks to its size, perhaps thanks to its somewhat narrow sound tube, when fitted with Comply tips, this earphone isolates as well as I’ve heard- that despite bearing a sound bore. If you’re a frequent flyer, the NS-U1’s bass and isolation should overcome anything you contend with.
I’m glad that this review is over. The NS-U1 is one of the most uncomfortable earphones I’ve ever used. I’ve got minor blisters forming in my right ear canal from the foam flange bunching too tightly against my skin. The NS-U1 is just too big for me. It stretches out my meatus out everywhere. The proprietary cable may fit poorly for glasses wearers. Because bass is big no matter what you do, it is my opinion that people after the NatroSound circuit, but who don’t really like big bass, will be put off by the NS-U1. I’d like to see an NS model with a lighter-footed bass.
The BD4.2 was killer. The NS-U1 could be killer. It is my opinion that for 200$, it is about as good as you could hope for in a bassy 200$ dynamic earphone. That you can flip a switch and get a different spatial presentation, is a unique and powerful feature. But it comes at a price: NS-U1 is just too big. And while it is an elegant solution, I’m waiting for its smaller, younger brother or sister to hit market.
As it is, A for effort and C+ for follow through.