As TWS seem to be very popular of late, with many companies (large and small) releasing wireless models, this thread can serve as a space to group the different models available and new launches.
As a first addition to this thread, here is my review of the Hifiman TWS600. The TWS600 is not a new model but I was sent it by Hifiman for review so I thought I would share my impressions.
As always, this review is available in Spanish (and English) on my blog.
Review - Hifiman TWS 600
Let me first say that the TWS600 were very kindly sent to me by Hifiman for review. They haven’t requested anything in exchange for sending them to me, in fact, they haven’t even requested that I actually post a review, they just wanted to help out with the launch of my new YouTube channel.
Now, I would like to point out that I will continue to be unbiased in my review of this (and any other product I may receive for review) but it is obviously worth noting that these have not cost me anything money wise to be able to test them out, so take that as you may.
At the time of publishing this review, they are available directly from Hifiman for $69, which is a big reduction from their original price of $199, and makes these much more of an interesting option at that price. There is a trend of TWS IEMs at the moment and while I have tried a few (and I some others incoming for review), this is the first time I have spent any considerable time with a set.
Build and comfort…
The IEMs themselves have a very futuristic look to them and, while the charging lights are on, they look as though they could have been taken directly from a Sci-Fi movie. This will appeal to many people and probably not appeal to others. Personally I like them. They are not the smallest TWS set available but they are not so big as to be considered bulky.
The IEMs came with the charging case, a USB C cable for charging the case and a large variation of tips (more about tips in a moment). As with most TWS IEMs, the case is used to recharge the IEMs when not in use, increasing the use time by a considerable amount, which is already pretty good as it is.
However, one of the issues with the case is the size of the cutouts where the IEMs sit for charging. These are pretty small and if using larger tips on the TWS600, this can cause issues with them charging correctly and even closing the case.
The IEMs are completely made of plastic, which is to be expected, and are pretty lightweight for their size. Once they are seated correctly in my ears, using foam tips, I do not feel any additional discomfort in comparison to other IEMs that I am used to using.
The thing to note there is that I said “using foam tips”, which is a bit of an odyssey itself due to the fact that these IEMs change their sound dramatically based on tips. I will explain more under sound but let’s just say that I found the best sound to be while using the triple flange tips, however, I also find those tips very uncomfortable and cannot stand them in my ears for more than 10 to 15 minutes.
In general I have no complaints with the build quality of the TWS600 or the looks of it (which is obviously personal taste), I think that they seem to be generally well built for a set of TWS IEMs at this price point, especially with the Hifiman name on them.
Now, I want to preface this section by saying that I have had issues with my phone (Xiaomi Redmi Note 4) and the TWS600. I believe that this is completely related to my own personal phone and not the actual model of phone or IEM. Using a Lenovo Tab 4, or PC, I have not had issues, so my comments are based on using them with the Lenovo Tablet and with a laptop.
The connectivity of these is great. They are quick to establish a first connection and are almost instant when reconnecting after charging. At no point did I lose connection and I can’t confirm if the range of 150m claimed by Hifiman is correct but I can confirm that I moved all around my office, outside in the workshop, as far as the other end of the warehouse and even upstairs to another office and had no connection drop outs, that is pretty impressive.
The IEMs offer the same basic functionality as most other TWS sets, with a single click (on either side) to pause/unpause, a double click for next (right) and last (previous), and a triple click for volume up (right) and volume down (left). Holding the button for a few seconds activates the voice assistant.
I did have a few weird occurrences here though, as sometimes (it happened 3 or 4 times, both on the tablet and on my PC) after connecting the next and previous functions would be reversed, with the left side doing next and the right side previous. At first I thought it may be due to me pulling them out of the case in the wrong order, however, the volume function always worked correctly (right up and left down) so I am not sure what happened there. A quick reconnect cured the issue.
One thing to note is that the button for these functions is placed in the center, almost exactly over the point where the IEM is inserted into your ear. This means that when pressing the button, you are also pressing the IEM into your ear, which can be very uncomfortable if using the triple flange tips for example, as the tips extend far into your ears.
Other things to note about functionality is that once connected to an Android device (I have no idea about Apple, sorry), the device will show the remaining battery of the IEMs. It is also possible to use them in a mono set up by just removing one IEM from the case.
Here is where it started getting a little… different.
When I first put them on, completely ignoring the card included in the box from Hifiman saying “Do not judge before 20 hours of burn in”, I found them to sound very strange. The mids were very exaggerated, with not much else, to the point of being painful at times.
I decided that I would follow the advice from Hifiman, so I connected them to my tablet and played music through them for more than 20 hours before trying again.
After the burn in, they did sound very different to my first experience, in a much better way (which wasn’t difficult )
But this is where the tip rolling started.
I literally tried every tip that Hifiman included in the box, along with many other tips I had available, and the sound was different with every tip, although there was a consistency to the signature of the sound.
The TWS600 are a very mid centric IEM, that seems to be their focus as an overall sound signature. Playing around with the various tips made changes in the bass and treble ranges without ever losing that mid-centric sound.
The mids are well done and it shows that Hifiman seem to have aimed for this sound signature on purpose, as they do not seem to be getting it wrong, it is just aimed towards a sound signature that I am not used to.
The triple flange tips did bring up the bass amount considerably, although still rolled off in comparison to the mids, to a quantity that I would consider acceptable for a lot of vocal music that doesn’t need much bass, however, due to the fact that I found these tips so uncomfortable, I couldn’t spend the time necessary to give a detailed opinion on the IEMs with the triple flange tips.
With the foam tips, I did spend a lot more time listening and working through my test list and other combinations an genres of music. However, with these tips, the music was very mid centric, and I personally found them fatiguing.
To give an general idea of how these sound (without the triple flange tips), they reminded me of the sound signature that Bose was so fond of with their speakers up until some years ago. I was never personally a fan of that sound but obviously not everyone would agree as Bose made itself into a household name based on that sound signature.
If you are someone who likes a lot of bass and sub bass rumble, this is not something that you will find with the Hifiman TWS600. Instead you will find a sound that is clearly intelligible, throughout the whole vocal range. This actually makes them very good for calls, conferences and even video consumption, although they are not my preferred signature for music listening.
I also feel that the lack of codecs available play a big part in the final listening experience, as they only use AAC and SBC codecs.
As far as the microphone quality, I didn’t get to use it too much due to the issues with my phone, but for the few conferences I used the TWS600 on, the reports from the other end was that it was satisfactory.
I know that this review is lacking in details about sound and my usual references to songs or genres, but to be totally honest and blunt, I didn’t enjoy them that much for listening to music and I couldn’t cope with the triple flange tips for long enough to give a coherent review (although that is obviously a personal comfort issue).
The commodity and convenience factor is obviously there, making them very easy to grab out of the case and just connect, so for someone who wants something that can easily be carried around with a good battery life and is always available for quick calls (or not so quick calls) then these will certainly fit the bill.
As they are IPX4 rated, they are also a good option for sports, as long as those sports aren’t under water of course. I think that they would work well in a gym situation, with the long range and great connectivity, you could leave your phone in your bag in the locker and just wear the IEMs. Although, if you are strongly into bass while training then maybe these would be a little lacking in that respect.
For video consumption, I also think that they are a good option. If you are someone who watches a lot of YouTube videos, or shows etc., while on the move, then these could serve you well as you will never find yourself having to rewind to see what the person said. Oh, did I mention these can get extremely loud? As in, way louder than I could ever see anyone needing. I used them a fair bit for YouTube content and was happy with the results.
So, although I am not a fan of these IEMs for music, I do think that they have certain traits that would work very well for some people.
Again, many thanks to Hifiman for sending these to me for review, it is much appreciated!
Superb review sir. Excellent content with lots if detail.
Much as I have enjoyed HiFiMan products in the past, I couldn’t stand these
I was looking for an “audiophile” true wireless and was hoping these would be they, but no bass at all.
I would have been disappointed in them at $19.99; in fact, I OWN $19.99 wireless sets that stand head and shoulders over these.
Here is my review of the KZ S2, a budget alternative in the TWS world. As always, this review is available in Spanish on my blog and is also episode 6 of Acho Reviews on YouTube (in Spanish).
KZ S2 - Review.
I ordered the KZ S2 from Indiegogo when they were first launched, for a super early bird price of around 20€. I opted for the white finish as I don’t have any white IEMs (at least I don’t think I do) and they took a while to make it here due to waiting for them to go into production and then shipping issues with the pandemic etc. but they finally made it and after a few weeks of using these true wireless IEMs, here is my review.
Build and comfort…
It has been a while since I received any KZ products but it seems that the packaging and presentation has not changed much since I received the ZS10 Pro and the ZSN Pro last year.
A standard white box with an outline of the IEMs on the outside opens up to find a simple white case in which the IEMs are contained. Under the plastic insert in which the case sits, there is a short USB C charging cable, a couple of set of silicone tips and an instruction booklet.
My first impression is that they look pretty cheap, both the case and the IEMs, in a plain white plastic with “KZACOUSTICS” printed on the case and the drive count printed on the IEMs in silver lettering. After while though, the look of the IEMs has actually grown on me, but I still think the case looks very cheap, then again, to be fair, they are very cheap!
The case is pretty light, mainly because of the plastic build and the fact that it contains a battery of only 500mA. There is no quick charge function, either for the case or the IEMs, and for some reason they have decided to put the USB C connector on the bottom of the case, meaning you need to lay it down to charge it. This is not a huge issue but may mess with some peoples OCD.
Having the case laid on its side to charge also means you need to use both hands to remove the IEMs from the case but I have found this to be true even when not charging, I have not yet managed to master the technique of removing them from their case without using one hand to hold the case and the other to pull out the IEMs.
The spaces in the case are large enough to take the IEMs with foam tips but it is a good idea to make sure they are seated correctly and charging (the red lights are on). I haven’t tried them with anything larger than foam but my guess is that they wouldn’t fit in the case correctly.
The IEMs themselves are small and light, which makes comfort nice as far as weight goes, although due to the shape of them, the top part rubs against my ear and causes some discomfort after extended use. That is obviously a very personal thing due to my own ear shape, everyone is different and this may not be an issue for your ears (or you may find them very uncomfortable) so each will have to reach their own conclusions on that one.
I have mentioned in basically all of my IEM reviews that I prefer foam tips, however, for some reason I actually prefer silicone tips on the S2, finding them more comfortable.
A drawback about how light the case and the IEMs are is in regards to battery life. As I mentioned above, the case only has a 500mA battery and in the IEMs it is 40mA. This means that playback is not that long. I believe KZ claims up to 4 hours of listening time plus another 14 hours when charging from the case. As they say “Up To”, I don’t know at what volume levels they have tested this but my guess would be closer to 3 hours per charge. This is a long way from the Hifiman TWS600 I reviewed recently which had 5.5 hours per charge plus another 33 hours from the case.
One last gripe about the battery is the charge times. As said, there is no quick charge, they even warn you against using a quick charger, and the IEMs take 2 hours inside their case to reach a full charge (so, 2 hours charging for 3 hours of playback) and the case takes 2 hours to charge also. I feel that quick charge, at least for the IEMs, would have been a huge improvement.
As far as connectivity, they use the AAC codec which is not exactly a highly regarded codec, without and Aptx HD or LDAC. They do use Bluetooth 5.0, which should improve connectivity but I have had a few dropouts and the range is not very good. They claim 20 metres although my experience has been more like 12 and there is no hope of leaving the room your device is in, which after being spoiled by the connectivity of the TWS600, is pretty poor.
The dropouts I mention are not regular but now and again they do suffer from a few weird moments, like the left channel dropping out or them refusing to connect. A quick disconnect and reconnect fixes the issue but it can still be a bit of a pain, especially if you are in the middle of doing something else. There are also instructions in the manual on how to reset the IEMs if you have any issues.
For control, KZ have opted for touch control rather than a physical button, with one tap to play/pause, two taps for next/last track, a 2 second press for activating the assistant and a triple tap to activate what they call “high performance mode” (more on that later). The touch works pretty well, with most of my taps being recognized, as long as the taps aren’t too quick. If you do a quick double tap for next track, it usually only recognizes a single tap and pauses the music. It is also worth noting that there is no volume control capability from the IEMs, so this has to be done on the source device. It is not the end of the world but I would much prefer to be able to increase or lower volume direct from the IEMs themselves.
Please note that all of my impressions regarding sound have been made using the silicone tips. I did try using foam tips (which are usually my preference) but it dropped the overall volume by quite a bit. I played around a bit to see if I could fix the seal issue but due to the shape of the nozzle, it seems to open the foam tips I have too much and I can’t get a correct seal.
The KZ S2 have a very V shaped signature, with an emphasis on bass and treble but with a dip in treble that removes a lot of air. To be honest, the sound signature of them I would class as being fun. I don’t think that they should be considered as reference for anything (nor do they say they are) and should be looked at as an IEM that is for enjoyment rather than detailed listening of music.
In the bass category, there is plenty. In fact, I have not found a single song where I thought it needed more bass, where I have found plenty of songs that had too much. The bass extends pretty low, getting down into sub bass category, and the higher end of the bass rolls over into the lower mids, not so much as a bleed more as an invasion. That is partly due to the recessed mids but also due to the excessive amount of bass at times.
Working through my normal playlist, I found songs like “Royals” by Lorde or “Way Down Deep” by Jennifer Warnes, I found the bass to be excessive and to literally drown out a lot of the rest of the spectrum. On a song with a huge amount of bass, such as “Bury A Friend” by Billie Eilish, it is a wall of uncontrolled bass, but then again, so is the actual song itself.
On songs where the bass guitar is recorded at a more balanced leve, such as “Smooth Operator” or “No Ordinary Love” by Sade, the bass actually has a nice warmth to it and seems to keep itself more under control, although it still overshadows Sade’s voice which could do with being a little more present.
The intro to “Elephants On Ice Skates” by Brian Blomberg is slap bass which actually sounds pretty good until the “real” bass notes kick in, they then overshadow the slap line and make it seem like there are two different basses, one artificial and the other a bass guitar.
Where the bass did perform really well was with instrumental EDM, and even some 80’s Electro, where the bass felt huge and smooth, giving the impression of listening to the tracks on something much bigger than these tiny IEMs.
Moving to the mids, these are recessed, excessively in my opinion. I have nothing against V shaped signatures when listening for fun, but in the case of the S2, I certainly think the dip after the bass is too much. On the instrumental EDM I mentioned, this is not actually an issue, but music that depends on vocals suffer. I mentioned this above with the two Sade tracks, where her voice could certainly use some more presence, but I also found it to be true in many other tracks.
“No One” (the acoustic version) by Alicia Keys is another example, “Hotel California” by the Eagles is another, most of the Dr.Dre tracks I listened to also suffered, and the list could go on.
Reaching up into the treble, the treble is back to being more present than the mids (which is not exactly difficult) but it seems to drop of pretty quickly, which removes some of the airyness that it could have to counteract the bass heaviness.
There also seems to be a dip in the treble tuning that works pretty well to avoid sibilance to some extent. Not all tracks are sibilance free but they are not overly exaggerated like on other offerings (some of which are from KZ themselves). They certainly can’t be considered bright.
In songs that I usually find plenty of sibilance in other, brighter, IEMs, such as “Hope Is a Dangerous Thing” by Lana Del Rey or “Sugar” by Francesco Yates (the acoustic version), the treble is pretty well contained. However, in “The Expert” by Yello and “Rockabye” by The Mayries, it is a little more noticeable but still not enough to be painful (just a little irritating at times).
As far as soundstage and imaging, they are nothing to write home about. Most IEMs (at least in this price range) are not very wide but I would say that the S2 are even less than normal. You still get a good stereo presentation but it is very close. The imaging is also not great, I mean, it is not terrible but as the presentation is pretty narrow, in songs like “Letter” by Yosi Horikawa, there really isn’t anywhere for the pencil to go.
While on the subject of stereo imaging, I have found something that has struck me on some songs. I sometimes get the sensation that the right channel is ever so slightly ahead of the left channel, causing a fake sensation of reverb on songs that already play with this effect in the recording. It can also sometimes make me feel as though the voices are slightly focused towards the right channel, due to that channel leading. It is difficult to explain and is not always noticeable but it is the equivalent of panning two identical voice tracks to the left and right in a recording and then nudgin the right track a couple of hundred milliseconds in front of the left.
With regards to timbre, I have mixed feelings. Whilst in the lower registries everything seems to be pretty natural (if we ignore the bass boost), in the upper registries some instruments present a slightly metallic sound to them. This was noticeable in songs like “Jack of Speed” by Steely Dan or “No One” by Alicia Keys, where the snares and guitars presented a metallic shine to them in the higher registries.
I want to mention video briefly as the “high performance mode” that is accessed by a triple tap is actually aimed at video consumption. When you turn this mode on it cuts the latency of the IEMs to a point where it is virtually impossible to claim you can see any sync issues of audio vs video. I used these for watching some series and movies on Prime and was pretty impressed by the response.
The recess in mids is not the greatest for making out voices when there are explosions and stuff going on around them, but I feel that the sound quality for video consumption is on a par with the majority of basic 2.1 setups that a lot of people have at home hooked up to their PC (in other words, normal people that aren’t focused on SQ )
This mode does reduce the battery duration though, so you would need a backup if you wanted to watch Lord Of The Rings.
As I mentioned in my review of the Hifiman TWS600, it seems my phone has issues with bluetooth headsets so I couldn’t really test them much. A few calls that I did make, the other side complained that the quality wasn’t great and I ended up switching over to my Koss PortaPro which are my “go to” for most calls.
The KZ S2 has a list of things that could be classed as faults until we put it into perspective, they are a true wireless IEM that cost 20€ (at least when I purchased them) and they do a job that is more than adequate for that price.
The connectivity is not the greatest, the sound signature is overly bassy and lacking in mids with a bit of a metallic ring in the highs, however, they are not an IEM that I hate. In fact, I can think of plenty of occasions when I would be in the mood for them.
If you like plenty of bass and enjoy EDM etc. I think that you would probably enjoy the S2. In fact, if you are not going to sit and analyze the sound, I think you would probably enjoy them when you are listening to music while doing other things, making the most of the TWS commodity. They are IPX5 rated so they are a decent option for the gym and would certainly provide plenty of that bass that so many people enjoy while training.
For video, they are also acceptable with the “high performance mode” on. The sound signature is not the greatest for movies and series but is acceptable.
I would say that the KZ S2, although they are not the greatest in sound quality, are a pretty decent set of TWS IEMs to just throw in a bag to have handy at all times, at least at the price I paid. If they cost double then I think I might try some other models before picking these.
Heard this at CanJam. I’m not going to lie. Easily one of the absolute worst audio products I’ve had the displeasure of hearing in years. Sounds literally like a telephone call. This isn’t surprising after crin showed his measurements. “The Worst Sound” indeed.
On a higher note, I’m gonna have to try this QCY T5 thing…
At first I thought you were referring to the KZ S2 I just posted and was going to say it’s not that terrible, then I realized you were replying to the first post of the thread…
Great review @SenyorC.
This is my review and impressions of the QCY T5, as always, this is also available in Spanish on my blog (link in my profile) and also is available in video format (also in Spanish) on YouTube.
I seem to have tried out more TWS stuff in the past month or so than anything else. To say that I am a person that prefers cables wherever possible (not just in audio but also cable vs wifi, power vs battery etc.) it has actually been fun to move around with these TWS IEMs in my ears and not be tied down.
I very recently reviewed the KZ S2 which I thought was a pretty decent option for the 20€ that it cost me (you can see the review here: Review - KZ S2) but that was at a discount price and the QCY T5 that I have here now is 20€ at it’s normal price, so, I’ll give my impressions on this IEM but I’ll also compare it to the KZ along the way as they are competing at the same price range (although I think the KZ is now more expensive).
Build and comfort…
The T5 is presented in a simple white box with a see through top and the contents basically identical to those included with the KZ S2: the IEMs, the case, a couple of spare silicone tips, a charging cable and a user manual. The only real difference is that the T5 has a micro-USB cable whereas the S2 used a USB-C cable for charging.
As far as build quality, it’s not very impressive. A plain black plastic case that feels cheap and a set of IEMs that sort of mimic the shape of the Apple Airpods but in a more generic way. The plastic used is a matt black finish and just looks cheap in general. I guess the case and the IEMs look cheap because they are.
With the KZ, I mentioned that the case was very light, well, in the case of the T5 it is even lighter, that is due to the case having even less battery capacity (380mAh instead of 500mAh on the S2) and I already complained about the KZ being week in this regard. The battery capacity of the IEMs is actually identical, at 40mAh, but they do seem to last longer on the QCY (I got 4 hours out of them at reasonable volume instead of the 3 I got from the S2)
There is no quick charge function here either. It is a basic micro-USB charge port with half of the input of the S2 but still takes around the same amount of time to charge (as the battery is smaller). At least QCY haven’t put the charge port on the bottom of the case though!
As far as comfort, they are actually very comfortable, at least for me personally. The are easy to place in my ear and give me a good seal even with the standard silicone tips that came with them. In fact, I have again found that I prefer silicone tips on these IEMs rather than the foam tips I usually use.
I find the QCY T5 to be strange as far as functionality. It’s probably just a case of getting used to them but they are different to all other wireless IEMs (and headphones) that I have tried so far (at least, as far as I can remember). Personally, I just don’t find them logical.
The on and off part is simple enough, just like any other TWS IEM, you place them in the case and they turn off and start charging, you remove them from the case and they pair, so far so good. However, for play and pause it is a double tap, for next or previous track it is “keep pressing until it changes”, a triple tap on the left is assistant and a triple tap on the right takes you into gaming mode. It also took me a while to work out where to touch exactly. I still find myself confused at times and there seem to be times when it just doesn’t acknowledge my touches. I am not sure if I just keep hitting the wrong spot or if the IEMs are just ignoring me.
Again, these IEMs lack volume control functionality, something that I would prefer to have on a BT earphone/headphone.
The manual also mentions something about a “3 way calling” function, which allows you to put phone A on hold while answering Phone B and then put Phone B on hold and answer Phone C. I haven’t tried this function as I spend enough time on calls with one phone, nevermind three!
The IEMs connect quickly to each other and are also relatively quick connecting to the last device, however, I did find the range rather disappointing. When more than 5 or 6 meters away from the device, I would start to get some stuttering and going outside the room, even when very close to the device, they would soon start to have issues.
The sound signature of the QCY T5 is very different to that of the KZ S2. Where the S2 had a large emphasis on bass, the T5 is much more balanced and has much less of a dip in the mid frequencies.
As far as bass goes, there isn’t really a lot of sub-bass, at least down in the lowest registers, which means some tracks that depend on this can seem a little lacking when used to listening to them on other IEMs or headphones. Where songs like “Royals” by Lorde, “Way Down Deep” by Jennifer Warnes were far too exaggerated on the S2, this is not the case with the T5.
In the mid and higher bass frequencies, the T5 does a nice job. It keeps the bass defined and clear, without becoming overpowering, and is good at presenting even complex bass passages. “Elephants On Ice Skates” was very enjoyable on the T5, as were other similar styled songs.
When moving to the mids, there doesn’t seem to be any bass bleed that I can hear, and as the bass is a little more retained and the mids do not have the huge dip found on the S2, the transition to the mids is much better, allowing a much better presence of vocals.
The lower mids stay well defined even when busy and although they are not boosted, they still have enough life and warmth to allow acoustic instruments, such as spanish guitars and basses, to sound natural and avoid any boominess as found on the S2.
The voices sound lifelike and are present, mainly due to a bump somewhere around the 3kHz region. This made many tracks that I enjoy a pleasure to listen to. Nothing really seemed recessed.
When getting to the treble, again, I found them to be pleasurable. There is no huge dip to eliminate sibilance but at the same time, it is not so present to be irritating. On my typical tracks for testing this, there was still a slight presence of sibilance but nothing that made it uncomfortable to listen to. In fact, I found the treble to be pretty well balanced in regards to the other frequencies in general and presented a better sensation of “airyness” than the S2, due to not having that huge dip in the 10kHz region.
The width of the soundstage is pretty much typical for IEMs in the lower price tiers, not very wide, however, placement of images is decent and again makes for a pleasurable listen.
Dynamics and resolution are not outstanding, I wouldn’t expect them to be for 20€, but they do defend themselves well and don’t seem to turn to mud when presented with busy tracks. They are not on the level of some of the wired IEMs I have tried lately but are more than acceptable.
With a triple tap on the T5, it takes you into what they call “Gaming Mode” and this is basically the exact same function as the “High Performance Mode” on the KZ S2. This mode reduces the latency and, although I have tried it with video and not gaming, it does a very good job. Again, as with the S2, there is virtually no detectable lag between image and sound when watching videos, although this does reduce battery life.
I said when I reviewed the KZ S2 that they were a more than decent option for the 20€ that they cost me but I would look at other models if they were twice the price. The QCY T5 are not only the same price but they are in fact cheaper as their normal price is 20€ whereas that was the “Super-Early Bird” price for the KZ.
As far as looks, I prefer the KZ, and the same goes for functionality, I just find the KZ to be more logical for my own use. The battery life is similar on both (although the battery on the S2 is larger) and the charge time is also pretty much identical.
The “Gaming Mode” on the T5 does the same thing as the “High Performance Mode” on the S2 and I have no complaints with either of them.
Where things do change is in sound signatures. The KZ S2 has a huge amount of bass which can actually overpower the rest of the frequencies quite easily. This bass, along with a huge dip in the mids, does not just make voices seem recessed but also can affect the treble when a track has a lot of bass presence. The KZ also lacks some “air” and a bit of treble in general.
The QCY T5 is a different approach, with a lot less exaggeration on any specific frequency, giving a more balanced and neutral approach. I personally find the T5 to suit my tastes much more than the S2 and presents my usual music in a way that is much more palatable.
They are not perfect in any way, but they are enjoyable and provide the same commodities that the S2 do with a better (in my opinion) sound signature.
I still feel that that the S2 is a decent buy for 20€, I just think that the T5 is a much better buy.
Excellent review and comparison @SenyorC. As always.
I have been evaluating the Mifo 05 TWS earbud. I received a review sample from Sherry at Yinyoo, Amazon.co.uk. Product link:
Here is my review:
The Mifo 05 is a TWS (True Wireless Stereo) Bluetooth 5.0 earbud featuring a long play time (7.5 hours per charge and a total of 100 hours from the charging dock). The driver is a 6mm dynamic unit.
What’s in the box?
The Mifo 05 comes attractively packaged in a rectangular silver grey box with a colour image of the contents on the front. Inside you will find:
Mifo 05 earbuds
Charging case (2600 mAh)
7 further sets of eartips (1 set pre-fitted)
Micro USB charging cable
The earbuds are well-constructed from metal alloy and robust plastic. They have a textured silver finish, a Mifo logo in the centre and a small button on each side. Underneath, the brass-coloured contacts for charging can be seen. The left bud has a blue border and the right bud has a red border. Each earbud contains a 60mAh battery, enough for a claimed 7.5 hours play time. The 2600 mAh charging case is also well made from metal and doubles as a storage case when the buds are not in use. A total of 15 charges is specified. The buds fitted snugly in my ears using the pre-fitted tips and remained secure. A good isolation was obtained.
Enable Bluetooth on your device. Remove the buds from the case and they go into pairing mode immediately. Select “mifo 05” as the paired device in Bluetooth settings and you’re good to go! I tested the buds with a Huawei smartphone, as well as Xduoo X20, Hifi Walker H2 and Sony A15 DAPs. Connection and re-connection was very efficient. Various combinations of button presses are used for volume control and track access. I managed around 6 hours on a charge but this was at a fairly high volume, so I would consider the claim of 7.5 hours per charge valid. The connection was solid and I managed a range of around 6 metres before the signal began to break up.
The Mifo 05 produced a warm and attractive sound profile. Running a frequency sweep revealed an elevated mid-bass, a rise in the lower treble followed by a more pronounced dip, and a peak in the upper treble which added some brightness.
The general impression was of a gentle V shape, with somewhat recessed lower mids and a slightly soft treble tuning with some added brightness in the extreme HF. The impressive soundstage was one of the best features, being wide and spacious. This made music relaxing and enjoyable with no harshness. I obtained adequate volume with my smartphone but had to increase the volume considerably on my Xduoo DAP. The buds did have enough resolution to highlight the difference in quality between this, the two other DAPs and my smartphone. I found the best results were achieved with the Sony DAP so used this for the testing.
The bass did deliver some good low end rumble and the focus was on the mid-bass which was prominent with a small amount of bass bleed. Kiraly and Crevier’s “Music from the Sky” is an electronic spacemusic piece with a powerful sub-bass element. This came over well but did lose a little in immediacy with the definition just a little softer than ideal. The lowest notes were discernible but sounded slightly distant and lacked some detail. This was also the case with classical music with the lower strings and brass in E. J. Moeran’s “Farrago” sounding a bit hazy and missing the requisite “bite”. However, this did make for a very relaxing and slightly romantic presentation, which was very pleasant.
The lower midrange was at a lower level than the upper bass and was characterised by the broad staging which lent the sound atmosphere and gave a kind of “soft focus” effect. Detail was softened and separation was a bit vague but there was an attractive musical quality from the extra warmth in the lower mids deriving from the bass bleed, endowing this region with an attractive “bloom” which contributed to the wide staging. The midrange was somewhat recessed, with Al Stewart’s voice in “Time Passages” coming over just a little distant rather than being projected and sounding warmer than usual. The guitars and percussion were also slightly subdued. The upper mids were more prominent, with the lead synth in Isao Tomita’s “Ave Maria” dominating the presentation and leading to the delicate counterpoint being less easy to discern. However, the imaging was very good on this track with the electronic effects occupying every part of the stage.
The treble did lose a little energy and detail as evidenced in Andreas Vollenweider’s “Behind the Gardens” where the harp strings could have been a bit brighter and crisper in tone, and the transients were a little bit blunted. The staging, however, was very three-dimensional with sounds even coming from behind my head! The complex high frequency sequenced parts in “Delphi Dream” from David Wahler’s “Antiquus” had a touch less energy than usual, but the stereo imaging on this track was excellent with the movement very well portrayed. Overall the lower treble was quite lively but there seemed to be a dip in the mid-treble which gradually recovered as the frequency increased with the higher treble possessing some much-needed sparkle.
The Mifo 05 is a very good product and “does what it says on the tin”, delivering on its promises and scoring well in every department. It is well presented with good accessories, works efficiently and is simple to operate. It is well designed and made, has a good battery life and is also very comfortable to wear. Perhaps the only minor criticism would be in sonic terms where a little more detail and energy in the treble would have been appreciated.
The sound is relaxing, gentle and musical. It has an impressive 3-D soundstage and excellent imaging. It has a kind of “vintage” or “analogue” quality, and the nearest in sound to the Mifo 05 in wired earphones would be the Blon BL-03 or the new CCA CA16, with their warm presentation (which is praise indeed!) but the Mifo 05 just falls short in detail retrieval.
In ultimate terms, it does lack a little clarity and transient attack, but this is not surprising when listening to a compressed signal (Bluetooth) versus high-res files directly wired. This slight softness may also be the result of only having the A2DP codec. If the higher resolution apt-x codec had been available, I would have expected a more lively sound with more detail. The new mifo 05 plus does include apt-x and has a balanced armature driver so it should address these concerns.
The sound did improve after a reasonable period of burn-in and the choice of source did notably affect the presentation with my Sony A15 DAP delivering a more impactful sound which really suited the '05s. This was mainly due to a higher volume available via Bluetooth on this device, as I found the earbuds did perform better with a robust signal.
The Mifo 05 is a very good product. It has an enjoyable and relaxing sound quality and a very good soundstage and it is very well designed and made. The performance of the 6mm dynamic driver is praiseworthy and the minor issues with the treble are a fair trade-off for the convenience and freedom of wireless operation.
great review @Nimweth.
Yinyoo is offering a discount code on the Mifo 05. The code is KN85ZFCI. You can get £6 off at checkout. Product link is in my review above.
As is usual, my review is also available in Spanish, both on my blog (link in my profile) and on YouTube here: Ep.27 - Hifiman TWS800 - Esta vez sí!
Review - Hifiman TWS800
I need to start this review by saying that the TWS800 was kindly provided to me by Hifiman for this review, for which I am very grateful. I will be as unbiased and open about my opinions as always, however, it is worth noting that it has not cost me anything to be able to review this item.
The TWS800 are the latest release from Hifiman and are true wireless bluetooth IEMs that are currently available as a pre-order (at the time of writing this review) directly from Hifiman for $299. That is a premium price point for some TWS IEMs but it seems that they have put every effort into this product in order for it to meet the expectations one has when spending this kind of money on a wireless set of earphones.
Some time ago I reviewed the TWS600 (you can find that review here: Review - Hifiman TWS600 ) and I had a few complaints about it, mainly that it didn’t suit my preferences as far as musicality but also some other complaints about functionality. I was excited to try out the new TWS800 to see if Hifiman had addressed any of these issues and I can say that they have, at least the majority of them, but let’s look at it one step at a time.
The box that the TWS800 comes packaged in is very similar to the one in which the TWS600 appeared. Apart from the colour and change of image on the box, everything else remains the same on the outside. To be honest, I really don’t care what the outside of the box looks like, it’s the contents that matter.
Inside the box, without entering into the aesthetics of the content (which I will comment on in just a moment), we find the IEMs, the charging/transport case, a velvet drawstring bag, a large selection of silicone tips (including double and triple flange offerings) and a charge cable (USB-C).
Nothing out of the ordinary but nothing is missing, so the contents are as to be expected.
Build and aesthetics…
The first thing that stands out about the TWS800 is the aesthetics of both the IEMs themselves and the charging case. Gone are the plastics used on the TWS600, exchanged for metal plates on the IEMs and a metal exterior on the charging case. This is already a large set up from the previous model, giving them a much more exclusive look. This metal charging case is a fingerprint magnet, however, the velvet drawstring bag included is a nice extra that you can put the case inside when storing or in a bag, saving it from fingerprints and scratches.
The shape of the IEMs has also changed, as have the lights used, resulting in a more ergonomic shape which, even if they are larger, is more fitting to the ear than the previous shape of the TWS600. I’ll talk more about the comfort in the next section.
As said, the lights on the IEMs have also changed, losing the “molten lava” look of the older model and being replaced with simple blue/red LEDs located behind the plates, which are completely invisible when not flashing (searching for connection etc.).
The metal plates and what seem to be metal stems, do add to both the aesthetics and the impression of build quality. I have no way of knowing how these will stand up to the passing of time but I see no flaws that jump out as being a possible issue and they manage to do it while still being very lightweight (6.9g according to Hifiman).
The original TWS600 were not really uncomfortable per se, it was the fact that for you to get any kind of bass out of them, you needed to use the triple flange tips, which I find extremely uncomfortable. In the case of the TWS800, it is no longer necessary to opt for the triple flange tips which, in my person scenario, makes them much more comfortable.
The shape is also a better fit for my ears and although they are a little larger than the old style, they fit my ears well and are comfortable.
Obviously comfort is a very personal thing and will be different for everyone but in my case they are a good fit.
As far as I can tell (it is not mentioned in the manual), the IEMs only offer SBC and AAC codecs, at least I haven’t been able to have them connect any other way. It would have been nice to have at least aptX or LDAC capability to offer the best quality (or maybe they do and it is a user fault on my behalf). In my review of the TWS600 I said that this lack of codecs was to blame for the let down in listening experience but the AAC is actually impressive on the TWS800, much better than on other BT offerings I have tried lately with the same codec.
The connection distance, according to the manual, is between 10m and 35m depending on the environment. This is a big reduction from the acclaimed 150m of the TWS600 but is more than sufficient in my opinion. I have been able to move around my office and go out into the warehouse without issue until I moved right up to the other end, and to be honest, who needs to be 150m away from their phone?
A single charge lasts around 4 hours, depending on volume levels, and the case can recharge them in about an hour. This is not the longest lasting battery out there but is acceptable and the case can charge the IEMs up to 6 times more.
One thing that hasn’t changed as far as functionality is the next/last track allocation of buttons which I found strange on the TWS600 (I thought maybe it was just my set) but is the same on this new model (so at least I know I am not going crazy). The usual 1 touch is play/pause, 2 touches is volume up/down, 3 touches is next/last track and hold for 2 seconds activates the assistant. The part I find strange is that volume up is on the right earpiece with volume down on the left (which I think is normal) but next track is on the left earpiece and last track on the right. Now, this is not an issue but I find it the opposite to what I naturally expect, but maybe it is normal for others?
Finally, as far as functionality, they connect quickly, I have experienced no dropouts during playback and they made the interior of the charging case larger so you can store the TWS800 in it even with the largest of tips (something that was impossible and irritating on the TWS600). However, on the other side of the coin, this extra space means that it is possible for the IEMs to move slightly inside the case. I have had a couple of occasions where the IEMs have been in my bag and have moved slightly inside their case, this automatically makes them connect to my phone.
So on to the exciting part!
If anyone had read or watched my review of the TWS600, you may remember that they were not my favourite IEMs and a lot of tip swapping was needed in order to reach the conclusion that to get any kind of bass from them at all, you needed to use the triple flange tips (which I find very uncomfortable).
In the case of the TWS800, they still experience changes based on selection of tips, as do almost all IEMs, although it is nowhere near such a difference as on other IEMs and is certainly not a case of triple flange only like on the TWS600.
After trying out all of the included tips, plus others, I have settled on foam tips as not only are they my preferred tip for comfort on almost all IEMs but they also provide the best sound on the TWS800, in my opinion of course.
Before moving on, let me say that I am not a huge believer in burn-in, well, not that I don’t think it does change slightly with use (in the case of moving drivers), but I feel that the changes are very small and it will not change the overall sound of a driver much. In other words, if you don’t like the sound of something out of the box, burn-in is not going to magically change the tuning of them (this goes for headphones, IEMs, speakers and anything that has a moving driver). I do actually “burn in” headphones/IEMs, mainly due to the fact that it does not cost me anything to do it, I just leave them playing on another system while I am listening to other things. Usually I will listen to something briefly out of the box (maybe for a couple of hours) and then I will go back to them a week or 10 days later (depending on how many items I have backed up) after they have been playing for 10 or 12 hours a day for that week or so (usually in stints of 3 or 4 hours with an hour break in between). I don’t usually listen to them at all during that time, which sort of eliminates “brain burn in”. To be honest, I don’t usually notice much difference, if any, at least it is not enough of a difference to jump out at me as I haven’t listened to them in over a week and only briefly before that. It just means that when I test and review something, I avoid the “it sounds like that because you didn’t burn it in” comments.
The reason I am mentioning this in this review is that in the case of the TWS800, I do feel that the burn in has created notable changes. Don’t get me wrong, it hasn’t changed the sound signature or tuning of the IEMs, the result seems to be that it has taken a little of the edge off from the high mids that I experienced straight out of the box. When I first tested them for a couple of hours, I found that many voices were shouty and snare drums were a little harsh, but when I have moved back to them now, I find that the shouty and harshness is not present on most of the voices and snare hits it was before (on the tracks that I listened to). This can also be blamed on my mood at the time, or infinite other things, but I think it is worth noting.
Now, on to how these sound…
I had started to form my impressions that in the sub-bass, there is a slight roll off which, in addition to the natural human hearing of these ranges, means that really isn’t any sub-bass rumble that may be found in other V-Shaped offerings. But… I have found that when you manage to get a correct seal and positioning, that sub bass suddenly appears. In my case, I have had to push the IEMs rather deep into my ears to get that correct placement, along with the seal of the foam tips, but this has completely changed my experience with the IEMs. It is really amazing the difference that extra couple of mm of insertion makes.
In the general bass spectrum, if I don’t insert them that extra 2mm, the bass frequencies are not elevated, which will leave bass heads wanting more. However, with the correct placement I just mentioned, this creates a slight elevation in bass which is plenty for the majority of music that fits my tastes. Also, the bass is very well defined and controlled. Complex bass lines are easily reproduced, allowing details to shine and do not become muddy no matter how complex they may be. I am not a huge EDM fan, except on specific occasions, but I listened to some random EDM playlists on Tidal and found that, while these are definitely not overly bass heavy, they were very pleasant to listen to and had enough bass for me to be happy, as they let me appreciate some of the electronic details that get lost when the bass is too elevated.
In the lower mids, again we find a very neutral curve, without any elevations that are noticeable, at least to my ears. This means that the TWS800 are not headphones that can be considered warm, they focus more on detail and definition. Saying that, they are not overly bright or cold either. For me personally, depending on my mood and the music I am listening to, the neutral response of the bass and lower mids (with the correct insertion) are something that can give very pleasurable results. From my usual test list, songs like “Jack of Speed” by Steely Dan or “Way Down Deep” by Jennifer Warnes were very pleasurable in these parts of the musical spectrum.
Throughout the mids, a neutral response is maintained until we reach the higher end of the mids, just as we start to transition into the lower part of the highs. This gives plenty of presence to voices, both male and female, with a very nice presentation of some of the smoother vocals such as “Little Sadie” by Crooked Still of “These Bones” by the Fairfield Four. As I mentioned above, on first listen I did find some tracks a little harsh in these areas of the frequency range but listening to them now (over the past week), they seem to be much smoother. As an example, I found the snare hits and female vocals in “The Room” by Ostura to be harsh during my first listen but are now much more listenable. As is the voice of Beth in “Don’t You Worry Child”, there are still a couple of notes she hits that are a little harsh (they are on many IEMs) but at first I found the whole track to be difficult to listen to.
Up in the higher ranges, the TWS800 keeps the sibilance in check pretty well, as heard on my usual sibilance test track “Code Cool” by Patricia Barber. The song is on the verge of sibilance throughout all of her vocals but they manage to keep it there, just on the verge. The same can be said about Lana Del Rey on “Hope Is A Dangerous Thing”, except for a couple of “S” moments at the beginning, the vocals are nicely presented and avoid sibilance.
There also seems to be a decent amount of “air” available in the higher range of treble. Not a huge amount but still enough. In my personal preference, I would probably like to see a little more extension into the highest registers but it is more than acceptable, especially if we take into consideration that I am listening to a set of TWS IEMs with foam tips and using the AAC codec.
Soundstage and imaging…
I find the soundstage width to be more than average for a set of IEMs, maybe not quite as wide as a couple of sets but those are a minority. As far as placement of images inside the soundstage, I must say that I find the TWS800 pretty darn good. Using my usually test tracks for imaging such as “Letter” and “La Luna”, I found it very easy to place images and track even small movements.
Detail and definition…
I haven’t spoken much about detail and definition under the different frequencies but it is something that I feel is very present on these IEMs. Minor changes to the way a guitar is played, decays of notes, reverbs and echo’s, all of these are easily noticeable on the TWS800. I spent hours listening to a playlist I have of acoustic songs that are mainly pianos, acoustic guitars and female vocals, and I enjoyed hearing details in all of them. Each song presented the differences in the way the musicians play their instrument. As an example, with the live performance of “Trouble’s What You’re In” by Fink, it was easy to notice differences in each tap of the body of the guitar, movements in front of the mic, slight vibratos on the bass etc.
I am not saying that the TWS800 are the most detailed IEMs I have ever heard but they are very good and present many details that a great number of IEMs can’t.
When I received the Hifiman TWS800 my biggest hope was that it would be a (large) improvement over the TWS600. I can safely say that it is, in every way possible (unless you need 150m bluetooth range).
I am not an expert in bluetooth IEMs and my experience is quite limited, although I have had the chance to try a fair few models (many more than I have reviewed). The TWS800 is without a doubt my preferred TWS IEM to date. Almost all of the sets that I have tried have been focused on a V shaped signature, appealing more to those that favour a strong bass presence but that is not the purpose of the TWS800. It has enough bass for me to be happy but does not feel as though it is adding a bass boost to everything I listen to.
I will repeat that I have found the insertion depth to play a huge role in the sound of these. If I seat them as I would with almost any other IEM (where they are sealed and sitting comfortably), they offer a neutral sound with a slight roll off in the bass area. I actually do find this enjoyable on a lot of the acoustic tracks I listen to, however, some tracks in other genres seem to be a little lacking in lows. Once I push them in that extra couple of mm, the bass increases and the extension improves, adding those extra couple of dB that felt like they are missing otherwise.
The microphone works fine for calls, I tried it on a few and no complaints except for one when I was surrounded by a lot of noise, in that case I removed the right earpiece and held it in front of my mouth and the result was great.
All in all, I probably only have one complaint about these IEMs which is the lack of higher end codecs. Then again, I don’t spend most of my critical listening time with wireless IEMs, I use them for commodity and the result with AAC is the case of the TWS800 is rather impressive.
There are a couple of big recommendations in this price bracket of TWS IEMs, such as the Apple Airpod Pro’s but I haven’t tried them so I can’t compare (I only own one Apple product and that is a 10€ dongle). However, if anyone is looking for a good set of bluetooth IEMs that not only look good but also sound good, I think that the TWS800 are certainly worth trying out.
Great review @SenyorC.
Thank you kind sir.
Reviving a bit of an older thread here to say that I pre-ordered the new KEF Mu3. I’ve owned a lot of these TWS over the past few years. The first generation Bang & Olufsen E8s, the Master & Dynamic MW07 Pro, the Sony WF-XM3, the Klipsch T5 II Sport, and now I’m waiting on the KEFs, as well as the new FiiO UTWS3s. I’ll post some thoughts on those here.
They (Hifiman TWS 600) were recently on sale for $49. At that price, I thought they were OK to buy, possibly as a possible gift to someone who has only heard Apple earbuds. Sadly the TWS 800s were not on a bargain sale, because remembering your review, I actually thought twice before pulling the trigger.
Ultimate Ears Fits Initial Impressions
So, it all started when I was looking at mechanical keyboards. I have been using the excellent (non-mechanical) Logitech wired illuminated keyboard for years. Somehow when I was looking at Logitech related websites (Logitech G) I clicked on Ultimate Ears, which is owned by Logitech International. Ultimate Ears is known for Bluetooth speakers. Their new product, Ultimate Ears Fits is a true wireless IEM with the nearly unique (in it’s price range) ability to custom fit to your ears.
Unboxing photos appear here: What's in the box! - #3805 by pennstac
I ordered the UE Fits from the Logitech website, using the 10% off coupon. That reduced the price from $250 to $225. Shipping was free, and took just a few days.
After the unboxing comes the setup experience. The packaging is in a light tight inner packet. This is because the UE Fits are light sensitive until they are set up. The user needs to download the UE Fits app from the Play or Apple sites. Then the UE Fits are placed in the case, the app is invoked and the fun begins. You are instructed to pair ONE of the fits — only one will appear to be paired and this is normal. As you watch the blinking lights, the app instructs you when to begin inserting the still-larval stage IEMs into your ears. You should take a minute or two to do this.
I found that the rubber covered gel larval fits were not a deep insertion. You may fool around a bit getting them well placed, because the gel/liquid inside is well, gel/liquid, and wants to flow around. Finally, you’ll get them placed pretty well and go on to the next step - IN FRONT OF A MIRROR, in a SLIGHTLY DARKENED ROOM for maximum fun. Clicking NEXT will initiate the custom fit setup. You will be prompted to use your hands to hold them gently in your ears during this stage.
LASER LIGHT SHOW begins as bright violet comes glowing from your ears. A new SUPER POWER! After a few seconds of this, the IE Fits begin to warm up, and you think that this is what it might have been like in high school if your GF had a drier tongue. About a minute later it’s all done. The gel isn’t gel anymore, but has hardened into a mold of your ears.
The instructions say that they guarantee the fit for 30 days, so if you have somehow done it wrong, apparently you can go back and get a replacement.
The forté of this IEM is supposed to be comfort. Even though it is not deeply inserted, it seems to be more secure than most IEMs I use. I’m able to shake my head with not the slightest worry about them falling out. The comfort is definitely superior, although the soft silicone rubber is a bit unsettling at first. I could wear these for hours.
Isolation is also good, although not at the level of a triple flange Etymolic inserted so deeply that it’s anchored in your Temporal lobes.
Examining the newly-emerged from pupal status Fits, I can see that there has been some deformation of the opening to the ear canal. There are also some unique fitting contours along the now molded tip. I suspect that it is not productive to try and give a detailed description of the sound, as the customization is likely to affect sound.
Fortunately, the IE Fits APP comes to the rescue. Much like the Audeze app for the Cipher cable, the Logitech app permits sound customization. It comes with a number of pre-sets, including Spoken Word for when you use the app with the phone. There is also a 5 band parametric equalizer and the ability to save and name custom settings. I found the equalizer to be a bit simplified with no ± db markings, and at first my finger wasn’t moving the preset spots well, but eventually it did work out. The app has a brilliant “back” function so you can easily step through your tries.
I found that for my ears, dialing in a setting I call “Slight W” worked well, giving a bit of bass shelf, toning down mid-high treble, and raising extreme treble just a tad. We’ll see if break-in changes my prefs.
Overall, I found the sound to be relatively neutral. Perhaps a bit lacking in bass slam - not surprising at this price point given the other features. Using the spoken word setting made mid-mids just fine for phone use, and the few people I tested calls on thought the mic was nice and clear.
As this is a true wireless, I did get the feeling that volume was limited due to battery, and that turning it up beyond what I normally consider loud caused it to seem to be straining. CODECS are limited, and AAC seems to be it’s best.
That said, I listened to Santana, Africa Speaks and some Haydn chamber music to test for initial impressions. I give the sound a B. It’s not goofy, but it’s not spectacular. Of course, my ears have been spoiled for IEMs by using the Audeze LCDi3, but I think that I would seriously consider this for commuting on public transport where there is noise, for use when you might take phone calls, and for exercise and outdoor activity. The isolation is good and the sound is adequate. But the comfort is sublime.
That sounds like quite an experience.
So once the gel thingies are set, there is no going back, in other words, nobody else could use them?