Disclaimer: Hifiman TWS600 were sent to us free of charge in exchange for our honest review. We thank team Hifiman for this opportunity.

My video review:

I’ll be honest with you, I tried just a handful of true wireless earbuds from Sony but was not too impressed by them, the technology was still in its beginnings and battery life was too short even for a gym workout. I much prefer the wireless over-ear headphones, but since it is summer time and sun is scorching and sweating my ears, over-ear headphones are a no-go, IEMs is the only option. How about true wireless IEMs? Yes please!

Hifiman just introduced their TWS-600 true wireless earphones/IEMs and we are already putting them under our magnifying ears.

This comes as a big surprise since Hifiman never made true-wireless earphones, Ananda wireless and this TWS600 is their first foray in the wireless land and I welcome this change of pace. Want it or not, wireless is the future, it is more convenient and hassle free, it is still not truly high-end sounding, but we’ll get there one way or another.

Package Contents

TWS600 came in a thick card board box and with lots of foam inside for extra protection. Actually, this is the hardest and the thickest IEM box I’ve seen until now, I think both the headphones and the charging case can’t have more protection than that. Inside the foam a pair of true-wireless earphones and the charging case are resting

Underneath the foam you will find a user manual, a warranty card, 8 pairs of ear-tips and a USB type-C cable used for charging the case. I didn’t expect to see those 8 pairs of ear-tips, it’s a bit overkill, but a very welcome addition. 4 sizes for normal type of silicone ear-tips, 3 pairs of bi-flange ear-tips and a single pair of triple-flange deep-insertion ear-tips, there is also a pair pre-installed on the earphones themselves so the total number rises to 9 pairs of ear-tips!

Looks & Build Quality

TWS600 are entirely plastic-made but are quite good put together. The headphone shells are bigger than I anticipated, but that is normal since every piece holds not only the driver structure and magnets but also a battery, a Bluetooth chip and a charging circuit. The shell resembles a big bean but it is easy inserting and taking them out since the nozzle is shorter and thinner. The plastic shell has a smooth surface and overall a smooth and painless insertion. The small part that touches my ear lobe doesn’t bother me since it is very small, I even had them for a sprint yesterday and they stayed firmly and never fell down. Comfort levels are good, but not top notch since there isn’t an air port to take away the pressure between the air canal and the nozzle, maybe their next iteration will have such a port, it’s a must have for top level comfort.

Overall, TWS600 are looking fine but will not stand out from the crowd, build quality is also OK but not impressive since there are visible marks where the plastic came together, maybe a harder plastic or a metallic shell would leave a better impression.

I personally like the build quality and the overall design of the charging case a lot more. Once you open it up it looks very nice with impressive tolerance numbers and the plastic mold looks like a single piece.

When the case is charging the earphones, you will see a battery level on the case and once you connect the earphones with your Bluetooth source the battery level will be displayed on the sources display, in my case on my smartphone screen.

The earphones have a normal size nozzle, so majority of 3-rd party ear-tips should work with them no problem. I tried few IKKO and FiiO ear-tips and both worked and stayed firmly on them. Since, my ear canal is a bit shorter I could not use bi-flange or triple-flange ear-tips, even the small ones were too much for me. All my listening was done using the smallest silicone ear-tips and with memory foam ear-tips I borrowed from another IEM.

Technology inside TWS600

TWS600 are using Hifiman Topology Diaphragm, in short it refers to a diaphragm that features special nano particle coating on its surface to improve rigidity, detail and speed of sound delivery. As a result, it should sound more natural, more detailed and more controlled compared to usual cellulose drivers spotted in regular earphones.

They are also relying on a single dynamic driver per side powered by a hi-tech magnet and an advanced alloy voice-coil for a better full range sonic clarity.

It is important to know that TWS600 uses newest Bluetooth 5.0 version, with a compatible device and in an open space the transmission distance should reach up to 150m! (~492 foot!), Hifiman even shoot a video to prove that, here it is:

My laptop, desktop PC and smartphone are not BT 5.0 compatible so I couldn’t test those claims. However, in my apartment, even with two thick concrete walls between the audio source and TWS600 the signal was still going strong. In this regard it was stronger than the one on FiiO BTR1 and BTR3 that I tested few months ago.

TWS600 are IPX4 rated, so they are quite resistant to sweat and dirt but should be avoided in bad weather conditions like rain or extreme cold weather.

I really like that they weight only 5.9 g (0.2 oz) and once inserted firmly in the ears, it is quite difficult losing them while jogging or working out at the gym, I will use them mostly sprinting outside in the week-ends.

Battery Life

Battery life of the earphones is rated for 5 hours and a half, the charging case if offering another 33 hours of play time for a total of 38.5 hours, quite impressive numbers if you ask me. A full change of the earphones will take one hour and fully charging the case will take one hour and a half. If you forget them in your bag, they will stay in the standby mode for about 110 hours.

Since I am a loud listener and 85 dB doesn’t cut it for me when I am listening to some born to be wild tunes, battery life at around ~80-85% volume ended up being 4 hours and 46 minutes, at half volume I would probably reach the claimed 5.5 hours.

Tips on using the TWS600

Well, first of all both ear-pieces have just a single button on each side. A short press on that button will answer the call, will end the call or will pause your music playback, a two second press will reject the call.

In case you want to use the voice assistant of your phone, be it Siri, Cortana, Alexa or default Google Assistant just press the button on the left or right for two seconds and may your wishes be heard.

If you are listening to music double-press on the left ear-piece button to reduce the volume and double press on the right ear-piece button to increase the volume. Triple pressing the left button will switch to the next track and, do the same on the right button and it will turn to previous track.

The best part is that you can use the left earbud or the right earbud only if you want, just put the other one in the charging case and you are good to go. Love to chat with someone and listen to a pod-cast? No problem, TWS600 got you covered!

When you want to charge your earphones, just gently put them in the charging case and thought the two gold-platted pins each ear-piece will be charged in no time.

Test Setups

I used the TWS600 in three different setups:

• Connected to my desktop Aurora 7 PC and playing some Heroes of the Storm, in this setup I was curious if I will hear any lag or stutter.
• Connected to my smart TV and watching a movie
• Connected to my smartphone and streaming Tidal Masters

TWS600 paired instantly with my desktop PC and I decided to watch few youtube videos and play a match or two of HotS. It is very simple checking the lag via youtube, just check the lip-sync as it should be always perfect and…..drum roll…..TWS600 got it perfectly! The sound is quite clear, it breathes, doesn’t sound muddy and is 100% synced to the image. I tested one year ago a pair of wireless over-ear headphones that had such a bad lip-sync I needed to return them back, that is not happening with TWS600 and I couldn’t be happier than that.

The same happens when light gaming, as the movement of the hero is synced perfectly to TWS600, in few matches I never lost a beat, I didn’t feel any lag, they sounded as a normal wired earphone. So, I think TWS600 can be used no problem while watching youtube videos or light gaming.

I then decided to watch a Netflix movie and connected the TWS600 directly to my smart TV, it worked as a charm. I can now watch movies at night, without making a sound in the room. Cool thing is that I can control the volume with the TV remote or directly from the earphones themselves. Again, no lag, no nothing, just pure action-packed madness.

I sincerely see a very big potential in them, since nowadays are so many Bluetooth enabled devices that are playing movies or music. They even worked great at making calls. The Sony WH-1000XM3 that I reviewed recently sounded really nice over Bluetooth but were just so-so at making calls. TWS600 are much better in this regard, as dual microphones are working really nice and the caller is hearing me crystal clear and of course I am hearing him very good as well.

I then took my phone out of my pocked, fired Tidal Masters (works on Androind, should work on iOS as well) and took a serious listen.

Sound Performance

First of all, I’m a bit sad that TWS600 are not LDAC and aptX or aptX-HD enabled so it uses AAC protocol with my phone. Practically, it doesn’t matter if I am streaming Tidal Masters (Hi-Res PCM) or just Tidal Hi-Fi (16 bit PCM) since AAC has a transfer cap of 250 kb/s, creating a file similar of that of a mp3 file. TWS600 is basically sacrificing a bit of sound-quality with the AAC and SBC protocol in exchange for a stronger Bluetooth connection. With the cat out of the bag let’s get straight to music listening.

I. Bass

In terms of bass response TWS600 are doing alright, they have just a mild bloom in the mid-bass department, it goes not too deep and most of the time is on the smoother, easy going side. Bass has more than enough control but I would not characterize it as super controlled or hard hitting.

To me sub-bass is a little bit lacking in heft, slam and presence. There isn’t a lot of information up to ~35-40 Hz, sub-bass layers are harder to spot and feel, this is not a bass heavy earphone mind you.

Mid-bass performance is much better to a point where I consider it quite linear sounding, maybe just a tiny bit boosted by about 3 db for a pleasing mid-bass performance.

Listening to Infected Mushroom – Head of NASA I immediately felt a decent amount of bass and even few layers of it. However, TWS600 choses a leaner presentation and bass doesn’t slam as hard as it does on big planars, even speed and impact are affected a bit. You hear it but you can’t feel it too much. It is not a bass light earphone, more like a mild W-shaped sounding earphone that is more on the smoother and safer side.

With the stock small silicone tips bass performance could be consider linear, that has a good presence starting with 40Hz and upwards. Moving on to the memory foam tips that I borrowed from another pair of IEMs, things are improving considerably as I start to gather few bass layers and I started to head-bang a bit, a sign that bass performance improved, it just goes a bit lower and slams a tad better. If you care about bass performance, I dearly recommend purchasing few sets of memory foam tips. Not only bass goes deeper and it is better controlled, it also somehow kicks harder, with an improved slam and speed of delivery.

II. Midrange

At first TWS600 sounded dry, with a big drop in the midrange area, it was very apparent with voices as they sounded too laid-back at times. I let them play on medium volume and every 5 hours or so I charged and left them play again. I repeated the process an entire-day and took a serious listen on the second day. To my big surprise voices are not laid-back anymore, but on the completely opposite side, they now sound a bit forward to me…

I now consider them forward sounding when it comes to midrange, especially listening to music that has a lot of voices. In terms of overall midrange performance, this is probably the best part of this headphone. Midrange is not linear mind you but very present nonetheless and will be felt most of the time compared to the rest of the spectrum. Midrange has this look at me approach and can be tiresome in the long run. This kind of performance is not really surprising, since a big majority of high-quality dynamic earphones are sounding like this with an emphasis on voices, with a rounded bass and treble performance. From a W-shaped frequency response on the first day, TWS600 moves to an inverted-U shaped FR, what a change of pace…

III. Treble

Treble performance didn’t change much from the first day. Their treble performance is above average, so I am still hearing clearly the bells and the cymbals but they have a much shorter decay than they should. I am however, very happy that Hifiman didn’t artificially boost the treble performance to be in line with the midrange, if that would be the case the tonal balanced would be thrown out of the window.

Treble most of the time sounds smooth and laid-back with just a mild roll-off at the very top of the FR. That is why they are almost never aggressive sounding and don’t have a lot of treble presence. Treble is not muddy of something like that, it is clear and quite detailed, but just never too present.

Overall, I consider TWS600 rounded sounding where frequency extremes are rolled off, so the emphasis will always start with mid-bass and end with lower-treble.

IV. Transient Response

Since TWS600 are quite smooth and easy going, they will not impress too much when it comes to fast transients. Slam and impact were heavily affected, so faster paced music will not sound too engaging or hard hitting. In exchange, slower music will sound just great with a right pace and timing. Midrange decays much longer, bass and treble will decay faster so the stoplight is always on midrange.

V. Detail Retrieval

These are clean sounding and are not considered detail monsters. Don’t forget, AAC and SBC are having a lossy compression so the finest details will be missed, not because the driver can’t show those, but because Bluetooth compression will hide the finest details and micro-detail information. As a result, don’t expect TWS600 to awe you when it comes to micro-detail information and super accurate rendering of the textures or of the outlines (leading edges) of the notes. The notes sometimes are fuzzy sounding, again it is just a limitation of the BT compression algorithm.

On the macro scale, everything is in place, even listening to a full orchestra or to some heavy jazz tunes sounds like a complete package. Piano is very alive and present, voices are warm and soothing, all the string-based instruments have a longer vibration and a really nice texture. Only if you look deeper at finer details, on the micro scale, then it is quite clear those are very hard to spot and be impressed by.

VI. Soundstage & Depth

TWS600 impresses more by its depth than by its soundstage. Pin point imaging is really good, majority of high-quality IEMs are carrying such a good imaging and TWS600 is no exception to that rule.

TWS600 can’t push a lot of air, especially from its internal battery-operated amp, so soundstage size is small to medium and it is quite up-front sounding. Don’t expect swimming in a sea of sounds and be carried away by them. TWS600 is mostly forward sounding with a laid-back and smooth presentation.

It is important to know that these will not sound muddy, crowded or plain boring and that is a good sign in my book.

VII. Background Noise

TWS600 are having just a tiny bit of background noise, it is probably part of the Bluetooth protocol, otherwise I can’t make my mind where it is coming from. Even when you just connect them and no music is playing there is a very low-intensity hum, can be hardly spotted but in complete silence you will spot it. Even when the earphone is pairing and tells you “paired” you can hear its voice a bit muted and not very clean. Background is a bit grainy but once you push that play button you can hardly spot that noise anymore. To be 100% sure, I paired them with a smartphone, a desktop PC, a laptop, an iOS device and a TV and it was always there.

Maybe a Bluetooth 5.0 enabled device will not have the low-intensity hum I am experiencing, maybe you can tell me that, would really like to know your experience in the comments section below.

Since TWS600 are the first true-wireless earphones to be reviewed around here, I can’t compare them to other such products but I will say they are sounding as a ~$150 USD wired IEM, add another $50 for the wireless tech inside and the charging case remains as a bonus.

Conclusion

I see a big potential in these, once you connect them to multiple devices it’s hard going back to wired music listening. Even watching TV late night, light gaming or checking latest youtube videos becomes so much easier, just inserted them, press play and you are good to go.

This is not a perfect true-wireless earphone mind you, there are still many things to improve upon, starting with build quality of the earphone and finishing with the wireless tech. I hope their next iteration will carry LDAC, aptX-HD for true lossless music streaming and why not some Noise Canceling tech as well?

Judging all the traits they possess as a long battery life, more than decent sound quality, the wireless range and all the wireless tech, Hifiman TWS600 is a great addition to their portfolio at a very attractive price of $199. You can purchase them directly from Hifiman following this link.

PROS:

• Excellent packaging and a wide selection of ear-tips
• Nice fit and finish, good comfort levels
• Good depth and pin-point imaging
• Has a smooth and easy-going presentation
• Juicy and upfront midrange performance
• Non-aggressive sounding
• Long battery life
• Can be used with a wide variety of devices (Smart TVs, laptops, desktop PC, tablets, smartphones and so on)
• Good price for what it offers

CONS:

• Lacks LDAC, aptX and aptX-HD support
• Not the last word in detail retrieval and dynamics, sounds lean at times

ASSOCIATED EQUIPMENT:

• Sources: Xiaomi Mi Mix 2, Alienware Aurora R7, Lenovo ThinkPad T430, Sony Bravia 65XE9005
• DACs: Matrix Audio Element X, Matrix Audio X-Sabre Pro, Mytek Brooklyn DAC+, KECES S3, Burson Swing
• Headphone amps: Benchmark HPA4, Aune S7 PRO, Erzetich Bacillus, Headamp Gilmore Lite Mk2
• IEMs: IKKO OH1, FiiO FA1, KZ AS16
• True Wireless headphones: Hifiman TWS600
• Full-sized headphones: Hifiman Arya, Quad ERA-1, Sennheiser HD660S
• Loudspeakers: KEF LS50W
• Interconnects: QED Reference XLR, Aune AL3 XLR
• Power Cables: Isotek EVO3 Premier
• Balanced Power Conditioner: PLiXiR Elite BAC 400, KECES BP-600

Overall score 84/100

Sonics (Overall) 80/100

Frequency Response 80/100

Bluetooth codec support 75/100

Bluetooth Range 95/100

Comfort 85/100

Build Quality 80/100