Simgot ET142 AKA Prometheus
The newest IEM from Simgot is not without some minor controversy. Initial batches of the new Planar based hybrid from Simgot got some not so warm impressions from the regulars on the tube with some saying its good but the tuning is a bit hot. Some just outright did not like them. I do know on open listen they are not ideal. My own initial take on the ET142 was not all that complimentary of the IEM but this was one where I had a feeling a bit of time tinkering with its tuning nozzles with a bit of burning in would help. I have heard a lot of IEMs that don’t sound so good out of the box so the ET142 was yet another IEM that I don’t recommend actually taking seriously till you get some hours on the baking oven and I highly suggest trying out their included nozzles before assessing the ET142.
The sound gets smoother, more bodied with better cohesion, the trebles especially changed for the better. In other words, the sound has matured a lot and is not the grainy mess I heard on open listen. As of writing I have had the ET142 for a few months actually and it was due to Simgot pulling a bit of a surprise. Simgot looks at reviews and to their credit they have held onto the initial launch of the Prometheus AKA ET142 until they did some extra tinkering in the form of extra nozzles. They now include 2 more nozzles in their box package so you now get a total of 4 sets of nozzles including the two original ones that came with the initial batch of the ET142. With the ET142 getting a nice longer run in and with the new additional nozzles for the ET142 the new name for the ET142 is now Prometheus. Simgot is ready to launch their newest planar hybrid.
A few disclaimers on the way I assess IEMs. First of all I always burn in every IEM I review at a minimum of a week's time. I do take some notes between open box and their final sound so it has nothing to do with my brain getting used to the IEM. Guys that have a knee jerk reaction to how the new Prometheus sounds out of the box and take the sound for what it is without burn in are doing the IEM a disservice in my opinion. That goes for every IEM. I am a very firm believer of getting the best out of every transducer that goes into my ears to know the sound before reviewing. Take that for what it's worth because there are a lot of reviewers online and on the tubes that don't care to do any of that. Truth is some IEMs reveal themselves right away and some don’t. Prometheus is the latter. These take a bit of time and tinkering to get the best of which I will describe here for my reader.
I use a minimum of 5 different sources. Which in my opinion is the minimum for really getting to know a sound. But that's just me. I see too many reviews of guys using a single source for their review and once again that is doing the IEM injustice, as there are some that believe sources don’t matter. In any case, here are my thoughts about Simgots newest Hybrid the Prometheus.
I would like to thank Fia Lam of Simgot for providing a review sample of the ET142. You can find more information about them
here. The ET142 has been burned in for a week period and has been listened to on and off for a period of 2 months. My sources used for the ET142 are the IBasso DX300Max, Ibasso PB5 amp, Ibasso DX180, Fiio M15, Fiio M15S, IFI signature and Fiio K9 pre ESS.
The old burn in debate might peep its ugly head on the topic but I know for a fact folks that don’t bother with any of that before doing any reviews, hence the not so positive reviews of the ET142. I suppose when you have over a dozen new IEMs on the review cue and no time to burn in anything, I can understand that. On the other hand, some IEMs need that time for the driver to settle and bring out its best version of itself. The ET142 sounded especially harsh on open listen. All that has changed due to Simgot recognizing a few aspects about the ET142 tuning that does not bode so well for western likes in sound tunings.
There are IEMs that don't need burn in but the ET142 is an IEM that absolutely requires it for them to show what they are about. To my surprise a lot of the criticisms I had earlier about the shouty nature and such are mostly gone but it also has to do with the new nozzles they have included. I am hearing much better cohesion between planar and PZT drivers which is yet another reason for burning in the Prometheus. Bass seems to have better clarity and definition. Mids sounds more smoother with an organic overtone, much more melodic, better density with more substantial note weight. It was the upper mids and treble which were the areas of contention on the open box listen. Trebles much better after a week of burning however it still has that Piezo characteristic timbre. The good news there is that It's actually integrated well with the Planar. Way better than on open listen. It has to be one of the best implemented Piezo drivers for its sound I can think of.
What they come with.
The new Prometheus comes with a gray colored rectangular medium sized box case with a magnetic lid. This case is just big enough to store the Simgot LC7 cable with its 3.5mm single and 4.4mm balanced plugs, A set of extra tips and the IEMs. This is a case where I feel the case does not account for the more substantial LC7 silver plated OFC cable which cost about $60-$70. It all fits in the case but barely. I think Simgot would have done better to provide a bit larger case for the Prometheus. It also comes with 3 sets of silicone tips and 2 new shorter filtered nozzles that clearly changes the tuning of the new Prometheus and if that's not enough, it also comes with a set of their tuning foams meaning you can customize the Prometheus to exactly how you like to hear your new Planar hybrid.
Sigmot tuning.
Simgot does several variances of the harmon tuning. Which some folks are not a fan of, but today's IEMs all seem to use a variant of the harmon tuning to one degree or another. It is now rare to see an IEM not have any pinna gain or an enhanced upper mids emphasis. The way our hearing portrays sound that emphasis is needed for sound balancing and presences for the mid bands. Prometheus is guilty of having a bit of extra in an early 2.5khz pinna gain with its stock nozzle and treble that has a spike at the sensitive 8khz region. If you end up trying their gold nozzle the sound does become a touch shouty and that 8Khz spike in the trebles causes a bit of glare for percussion noticed for crash cymbals for rock music. The mids are actually organic sounding with a smooth finish and its bass end is impressive with a boost towards its sub bass. Planar timbre is a thing for IEMs and while I perceive the Prometheus to have a timbre which is a touch soft it makes up for it with an organic smooth musical tonal quality. I really don't have issues with the timbre characteristics and surprisingly the PZT here does a splendid job with the upper treble notes, especially noted after burn in. The 2 new tuning nozzles are physically shorter and with more dampening material which lowers the areas I spoke about earlier.
The good news here is that with the inclusion of these two new tuning nozzles makes the Prometheus much more versatile. The Prometheus goes from analytical and a bit brighter in tuning to a much more musical and even a slightly warm one. Ya you read right, a warm Simgot? The nozzles don’t seem to hamper any of the technical traits of a highly resolving planar driver being used for the Prometheus.
The 2 new nozzles introduce a slightly warm one in the red ringed nozzle. The other set which is the same nozzle with different level of filter in it and black rings to differentiate from the other set is somewhere between the stock longer nozzles blue and copper and the new warm red ones. The initial longer nozzles have the most upper mids per Simgots harmon tuning philosophy and I had these nozzles long enough to actually get them to sound a lot like the new shorter ones. As they are, the gold nozzle has roughly 13dbs of pinna gain and to my ears does introduce a bit too much upper mids with the inclusion of that 8Khz emphasis. If the Prometheus was reviewed just using this particular nozzle, it would take a warmest sounding source and your thickest pure copper cable to tame that upper mid brightness.
Fortunately, we got choices. Using the longer blue nozzle things get a bit more interesting while still having what I am guessing to be about 11dbs of upper mids. This is the nozzle that comes preinstalled on the Prometheus. That enhanced 8 khz emphasis for trebles seems to highlight the upper mids even more so which makes the blue nozzle tolerable but not so much for your favorite rock tracks.
I know you're thinking, what would make these a good listenable IEM then? Even before Simgot created these two new shorter nozzles, I did some tinkering of my own. What I did was include the tuning foams from the EA1000 tuning kit. But that's a mod you say? Nope. If the inclusion of the new tuning nozzles are not enough for you. Adding a single foam piece underneath one of the included nozzles will smooth out the enhanced areas of emphasis for you.
For my ears I like a foam piece underneath the blue fired nozzle. It takes a bit of the edge off the trebles and the upper mids for me. A bit more clarity above the new black ring nozzles, yet similar in balancing. The new red ringed short nozzle brings down the upper mids of the Prometheus to about 7dbs which makes them sound more balanced, the blacked ringed one seems to be about 8-9dbs. Now we are talking.
Simgot has given the end user. Choices, that saying we all hear differently is so true. It all comes down to just how much upper mids and trebles you like. The included nozzles and foam pieces are all as easy as screwing them on and in my case just inserting a piece of foam underneath the blue nozzle. And with each nozzle change I would highly recommend tip rolling to get the best possible sound for your use case.
Trebles
I have heard plenty of IEMs using PZT or piezo drivers and the Prometheus has a very good integration of the PZT driver for its upper trebles air and detail elements. Its main point of contention is at that 8Khz where it clearly has some emphasis. Again, you can tinker with the foam pieces or the new included nozzles till you get that emphasis tamer than what comes with the copper nozzles. It's interesting that manufacturers seem to think they need to add another driver for upper treble extension and as you know PZT drivers were included to enhance that region. For IEMs that I have reviewed in the past, planar drivers seem to excel at trebles very well actually. I think I would have been more happy if Simgot used a more resolving dynamic driver for bass and just tuned the Planar here for mids and trebles. I know they have used the PZT in their quadbrids the SM4 and tribrid EW300 so maybe they are happy with the results of the PZT driver and carried over that to the Prometheus. In any case. If you're a treble fan you will be happy that the new Prometheus has plenty of treble presence and its extension is ideal. It might have a bit too much actually especially if you're sensitive to the 8Khz emphasized region. The copper nozzle is where it gets a bit much in the treble region in conjunction with the most upper mids for its tunings.
I doubt treble folks will complain about not having enough emphasis here. To be honest I actually like that the treble is not rolled off in the least bit. It's got a full on treble extension and presence for all things trebles. Tinkering with the included nozzles and foam pieces will get the trebles to be just right for you. As you can tell, all this takes a bit of time and my experiences with how I hear them now is in no way a knee jerk reaction to how they sound out of the box. This is one IEM where you have to spend a bit of time on it. In the end It will be worth that time to get them to sound just how you want to hear them.
Mids.
This is the strength of the Prometheus,
So here is where those tuning nozzles will play a part in how you like your mids tonal qualities. The foundation for some smoother full bodied mids are there. The nicely resolving planar driver does a very capable job with the mids presentation which is more bodied than the mids from the SM4 and is more spacious with a better stage than the EW300. Overall sound with the right source can bring out some really good layering in space. Imaging is a strong suit of the Simgot IEM and the Prometheus delivers with a well separated image. I noticed planar timbre was more evident on open listen for the mids more so than how I hear them now. Overall it has natural tonal quality but can be manipulated with the nozzles. It can sound brighter with a more forward female vocal presentation, also highlighting stringed instruments- copper and blue nozzles. Or with a slight warmth and more body highlighting male vocals with a more balanced mids presence-2 new nozzles red and black ring new shorter nozzles. The large planer driver used while giving a bigger sense of stage is not the most dimensional sounding. I would say dimensionalism is an aspect for sound that is difficult to relay correctly. We use the word holography and dimensional and how that translates to how I hear the Prometheus is that it sounds more single plane in sound or more neutrally present vs imaging that floats in space from much higher end IEMs for example. At the given price point this aspect is certainly not bad but something I have noticed as Bone Conduction drivers are the new bell of the ball nowadays which helps with the dimensional aspects of a sound. I have reviewed other Planar IEMs the Letshoeur S12 pro and Dunu Talos, both of which also has a higher degree of resolve. The new Prometheus not only goes toe to toe with them in how resolving the sound can be but It has much more in the way of versatility in its tuning via nozzles and foam dampeners vs both those sets.
Bass
Bass has a tasteful lift toward the sub bass with about 10 dbs of emphasis, an enthusiastic emphasized amount but not exactly basshead level. Simgot does not make basshead level IEMs, on the other hand I have yet to hear a Simgot made IEM with a weak neutral bass emphasis. Its bass ability is adaptable to all music types and genres but does portray the slightly quicker decay of planars for IEMs. And here is where I kinda miss the bass end of the old EA500 or better yet the EA1000. In comparison, that shorter decay does not bring the most textured bass performance. However, all is not lost, for something like speed metal and rock music with faster bass notes, planar bass is just as speedy as a well-designed BA driver. Advantage of the planar driver happens to be its speed, showing excellent tightness for the bass note. Now when it comes to a textured slower decaying woofer sub bass note, this is the area I feel a well vented dynamic will win just about every time for IEM applications. Prometheus has no issue handling a proper tonal character and emphasis for bass. The problematic area for me is in its texture for sub bass. Somewhat soft sounding but to be fair I am comparing the bass ability vs some of the best dynamic bass characteristics. For what it is, the bass end is very capable and even enjoyable. Its emphasis has enough mid to sub bass for proper pop, jazz, edm, hip hop and rock music but true bass aficionados will be wanting a bit more there especially from the sub bass notes from a quality perspective.
If sub bass especially is your thing for IEM performance. Even though the Simgot EA1000 bass emphasis is actually a bit less in emphasis. Its bass definition and texture are excellent at about the same price range.
Closing thoughts.
Simgots new Prometheus is one of those IEMs where they will benefit greatly with some time on the burn-in station and nozzle rolling is required, know this when going into a purchase. The good news there is that each of the 4 nozzles bring a different sound profile, and one is bound to suit your own likes in the sound balancing which can be even more fine-tuned with dampening foams which are included in the packaging. If the trebles are a bit spicy for you from using any of the nozzles, again them tuning foams will do wonders for how you like to hear your trebles.
I know Simgot has a following of enthusiasts that take their releases very seriously. The negative stuff you see and read about this IEM is not as bad as you think, and I don’t care who wrote or shot the video review about them. My advice is try not to take an open box review seriously. Because in my view that person is not actually testing the entirety of what the IEM is about or can do. The ET142 is an IEM that absolutely needs burn-in for better cohesion and fullness of sound. Then you have to tinker with the nozzles to figure out what sound balancing you prefer, then you have to tinker with your best tips after that to finish off that sound. For me it was a piece of dampening foam underneath the stock blue nozzle which ended up sounding good enough for me. The newer shorter nozzles Simgot has included on their newest packaging will actually get you closer to the sound balancing I have achieved, especially the black ringed short nozzle. If you're not one to tinker with nozzle filters you can just use that set. And it is with these newer nozzles that the sound achieves a good price to performance level for the Prometheus. Optimizing the sound of the Prometheus ends up being rewarding with an engaging musical sound, good technical chops with an organic tonal quality and why wouldn’t you want that for your new IEM. Thanks for taking the time to read.