[General Accessories] vectron:
This is a Review of KZ ZS1, ZN1, HDS1, and ED3c IEMs.

It has been awhile since my last review of ED9, ED10, and ATE, two budget IEMs from KZ which I still hold in high regard. One admirable thing about Knowledge Zenith (KZ), they never sit still and continuously push the envelope of budget pricing and new cool designs. That’s what you are going to find with their new HDS1 and ED3c additions to IEM catalog. But at the same time, they stepped outside of their typical $10 comfort zone with two new offerings, ZN1 and ZS1. Let’s take a closer look at what I have found.

ZN1 (http://www.amazon.com/dp/B0140WAP5S/?tag=vectron00-20)

Referred to as Smart Headset, ZN1 has a dual dynamic driver (8mm for bass/mids and 6.8mm for treble) with two independent sound chambers combined at the nozzle and a smart control unit with dual TI amplifiers. The control/amp unit requires to be charged (through micro-usb connector), with a battery lasting up to 10hrs, and it has an independent digital volume control +/- buttons, bass adjustment +/- buttons, and treble adjustment +/- buttons. While being adjusted, these parameters are displayed with corresponding values on a small high contrast OLED display. Furthermore, you also have a multifunction button to pick up and to answer the calls, and a separate Power button.

The control unit is a bit bulky and adds some weight to the cable while serving as “y-splitter”. Also, the cable from the control unit to 3.5mm gold plated angled connector is thick, and L/R cables going to earpieces are also on a thicker side. Earpieces are big enough to house two dynamic drivers, have a plastic housing, and a durable build that can withstand some abuse. They have a clear L/R marking, multi-venting for expanded open sound, and a short strain relief which is not a problem due to a thickness of the cable/shielding attached to earpieces.

In terms of a fitment, earpieces themselves are very comfortable and fit secure with a wire over the ear. But the added weight of control/amp unit and thick cable is not very comfortable to walk around with. Another thing, I was able to pair it up without a problem with my smartphones and tablets, but to work with DAPs you need TRRS to TRS adapter. With a smartphone it works in a powered and a passive modes, while with DAPs it only works in a powered mode and with an adapter. In my opinion ZN1 strength is NOT in a portable use, but rather to use with your smartphone or tablet for a portable entertainment, such as watching movies, videos, and playing games.

ZN1 gives you a full theatrical experience of an open/surround amplified detailed sound where you can adjust the depth and the impact of the bass and increase or reduce the definition and sparkle of the treble. Sure, you can also listen and enjoy your music while you are relaxing in the chair or on a couch, but walking around – I wouldn’t recommend. And if you run out of battery, you can still enjoy the sound in a passive mode, though without volume/bass/treble adjustment. In summary, I found it to be not as useful with my DAPs, but very useful with my Smartphone and Tablet.

Pictures.

ZS1 (http://www.amazon.com/dp/B017I75XOU/?tag=vectron00-20)

While testing ZN1, I was happy how it paired up with my smartphone, but wasn’t able to enjoy it to a full potential with my DAPs. It was a bit frustrating to the point where I was ready to “convert” ZN1 into a passive wired IEMs, but I'm glad that I didn’t. I’m sure KZ received a lot of feedback from their users, and decided to answer with ZS1 version which is basically a passive wired ZN1 without control/amp unit.

Just like ZN1, ZS1 features a dual 8mm and 6.8mm dynamic drivers with a nearly identical plastic shell and open vents, and the same L/R clear marking. Cable is thinner, closer to a more traditional KZ wires with their typical 90deg headphone plug, rubbery shielding, small y-splitter with a nice strain relief on each end, and in-line remote/mic going to the right earpiece for smartphone control. Everything was good until you get closer to earpieces where you have a rather long and stiff memory wire. I guess KZ decided not to use memory wire with ZN1 because wires stayed put behind your ears under the weight of control/amp unit, while not the same case with ZS1 – but they made it too long and stiff. Again, this is not a show stopper that going to affect a comfort of wearing ZS1, but I would have preferred a shorter memory wire and without a plastic termination bead at the end. Every time I take them off for storage and put them back on, I have to go through re-shaping of the memory wire which becomes a bit annoying.

With a design and a fitment out of the way, the next stop was a sound test. I was pleased to see that ZS1 had no issues working with any of my DAPs in addition to smartphone and tablet, but as soon as I start playing the music, my ears got blasted with a serious BASS cannons!!! I have no idea why KZ decided to tune ZS1 to a basshead extreme. We are talking about L-shaped sound signature with an overwhelming bass slam. Low end is deep and extended, from a thick thumping sub-bass to a boomy elevated mid-bass - both dominating the sound. But surprisingly, even with such massive impact, there was still room for a quality mids, though pushed all the way back in quantity. Lower mids have a full smooth body and upper mids have a nice clarity with smooth details. Even treble has a nice definition, though not as much airiness or brightness. Also, soundstage was pretty good, though with more depth than width.

Not wanting to give up, I started to tweak EQ and discovered that ZS1 has A LOT of potentials and can be transformed into a decent pair of headphones when you cut 6dB around 30Hz and 3dB around 60Hz. As soon as you trim that low end thumping and booming, you make a room for mids and treble to come up, resulting in a more balanced and smooth detailed sound. This EQ cut easily transforms ZS1 into a solid pair of great sounding headphones with a more ear-friendly tuning and a balanced organic detailed sound. Typically, I’m not a fan of using EQ, but sometime I can make an exception and SZ1 was it. But moving forward, I wish KZ would retune their sound signature to cut down on bass and to shorten the memory wire.

Pictures.

HDS1 (http://www.amazon.com/dp/B017NIQQSG/?tag=vectron00-20)

With HDS1, KZ went back to their traditional “formula” of small lightweight single dynamic driver design (this one has a small 6mm driver). It was nice to see all these bright fresh colors, instead of a traditional black or silver, and the build quality was solid metal. The shells have a clear L/R marking, short but sturdy strain relief, typical KZ thin cable with a rubbery/sticky shielding. Y-splitter was nice and small, but surprisingly it didn’t have any strain relief at the ends which I prefer to have. The headphones connector was their traditional right-angle gold-plated plug. The fitment worked both ways, wired up and wire down.

There was also in-line remote w/mic on the right side of the cable, but it was very cheap and plastic. I wish they would have used a sturdier metal capsule because if you crack this in-line remote – you expose the wire connection (speaking from a personal experience of another headphone pair that went straight to garbage). I also sensed some cable microphonics. Last, but not least, sound isolation is poor due to 3 large vents on the back of the shell – great for an open airy sound, but not good if you’re looking for a passive noise isolation.

When it comes to a sound analysis, HDS1 offers a nicely tuned mid-centric signature with a focus on mids clarity and resolution - great for vocals! A found very little sub-bass, nearly rolled off, and mid-bass had a neutral fast tight punch. Lower mids are lean, missing warmth of full body, while upper mids are the focus of the tuning - clear and detailed, and at the same time not a hint of harshness or graininess. Treble is extended, bright, crisp, well defined and not sibilant at all. The sound is mid-centric and airy, but at the same time missing some organic warmth and natural body. Instead, you will get a detailed resolving vocals, neutral quality low end, nice treble sparkle, and overall non-fatigue extended listening experience. Soundstage has a great width, an average depth, and slightly below average height.

Pictures.

ED3c (http://www.amazon.com/dp/B0174WO2LY/?tag=vectron00-20)

ED3c is another step closer to a traditional KZ design and sound, and also under $10. Here you will find a solid build quality, all metal lightweight shell in different bright colors (looking like the color was baked in), and a nice strain relief around the shell. KZ decided to do something more original by using handwriting font to spell the Left/Right which looks classy, but also hard to read, so I was using in-line remote on the Right side as my indicator since shells are symmetrical. The cable has typical KZ multi-color wires with rubbery shielding, small rubbery y-slitter with strain relief on each end, and a traditional 90-degree gold plated headphone connector. Microphonics was just average, and sound isolation was not bad at all if you use the correct size eartip and considering a small pinhole air-vent next to the cable attached to the shell.

I found ED3c to have L-shaped signature with a nice low end extension and a strong bass impact. Sub-bass has a nice heft, adding an underlying weight to support fast mid-bass punch. Bass itself is not very articulate or super tight, but has an Ok control and strong impact which tilts the sound toward the low end. Lower mids are warm and full but not muddy, upper mids are clear smooth but not very detailed. Actually, mids sound a bit artificial, especially vocals. Treble is clear, a little rolled off, smooth and non-sibilant. Though I hear overall sound to be more L-shaped than V-shaped due to a treble roll-off, I still wouldn't consider these to be basshead headphones. Soundstage was also nice with slightly above the average width/depth/height.

Pictures.