When writing reviews, or giving impressions of an IEM, or any product for that matter, it can be hard to predict how long something might last.

Unfortunately, despite initial impressions, my opinion now is that while seeming like a tank, the build of the GT100S is a bit of fool's gold. First of all, you have heavy earpieces attached to a non-detachable cable. So any time you drop one earpiece while putting the earphones away or what-have-you, that's a lot of force tugging on the cable.

The earpieces themselves seem almost invincible...and yet mine came apart. I'm on my second pair, and it has something wrong with the cable near the plug. I have to keep it kinked up to get sound out of both earpieces.

I stand by the rest of my review. Just be aware that if you pick these up they might not stand the test of time.


(not my pic)

I stumbled upon these Macaws randomly on eBay while looking for a lifelike David Hasselhoff mask. Decided to take a chance on them because they were tickling my spider-sense, and also I just really dig this form-factor(the VSD5 was my first, this is already my fourth). Aaaand the case kinda-sorta pushed me over the edge. They were already on headfi radar, and now that a few of us have them, with impressions being very positive, I figured they could use their own thread.



There are some useful instructions on the back for getting your new IEMs out of the packaging. If you don't want to resort to using a hammer.


Here's the GT100s with the Dunu Titan and Vsonic VSD5.





The in-line remote. It's nice.





The case.



And lastly, here's a pic showing the issues I've had with the accessories of this earphone so far.


Build quality

They come with three sets of filters(balanced, trebly, and bassy) which can be easily swapped out by screwing them into the housings, and while installing the gold(trebly) filters, a piece of said filter sort of threaded off(it's the squigly metal bit in the pic) and got lodged inside the earphone. I was able to get it out with a bit of effort. Weird. So I can't use the gold filters; a bit bummed out about that. Also, one of the tips ripped apart while I was taking it off. Never had that happen before.

Build quality seems exceptional otherwise. I have my reservations now after my issue with the filter, but I hope that's just some sort of weird isolated incident. Even the zombie apocalypse Aurisonics Rockets have had at least one reported build quality issue. It's also worth nothing that the filters are not the same size; the black(bassy) filters are larger than the silvers(balanced) for instance, which could impact which tips you use.

Fit

These are heavy as far as IEMs go, but I've not had an issue once I have them in. One of the reasons I greatly prefer using IEMs over-the-ear is because I like to be able to take them out and leave them hanging - for me it's like the earphone equivalent of having a pair of cans around your neck. And heavier IEMs have a propensity to swing and slowly descend when you leave them like that while moving around a lot, but so far I haven't had much issue with these, although they don't stay put up there as easily as something lighter like the VSD5. And again, if you want the earphones to fit flush you might need a specific set of tips for each filter since they're different sizes(the black ones are, anyway). They'll probably be a little uncomfortable for some, as the belly of the earphone is hardly ergonomic:



Sound

Twister has stated in his review/impressions that these sound like a hybrid BA+DD, but to me they just sound like a straight-up BA. Using the stock silver filters they are very lean(some people will probably hear them as being "thin"), with excellent detail retrieval and clarity. I'd also consider them, at least using the silver filters, to be a little bass-light. I've only briefly used the black filters, so I can't really speak on how much of a difference they make. They sound to me almost like what I remember the Ety ER4S sounding like, but brighter. Even when it comes to the shoving-detail-down-your-throat and holy-macrel-these-are-clear qualities of the ER4. They also aren't very impactful, so they won't make you feel like you're getting whacked in the head during drum solos; whether that's a good or bad thing is gonna come down to personal preference. I enjoy getting whacked in the head, myself.

Soundstaging and instrument separation are both very good(especially the latter); but whether that has anything to do with the inverted dynamic drivers is tough to say. Anyone wanna take them apart, flip the drivers around and tell us what they sound like?


Another point of note, is that they aren't terribly easy to drive, which is a bummer. I'm not sure what the point is of designing an IEM with smartphone users in mind and making it tough to drive from a smartphone(looking at you, KEF M200). I haven't A/Bed them against anything yet, but plan to against the Titan and also the VSD5. Pretty sure these Macaws are gonna hold their own against both, easily. For $70 they're easy to recommend, but here are some other impressions:

Twister's review and impressions:
http://www.head-fi.org/products/macaw-gt100s-hifi-with-mic-in-ear-earphone-silver/reviews/13359

Quote:

Excellent bottom and top end extension, 3D staging (soundstage expands both in width and depth). Sounds almost like a hybrid with a tight punchy low end and vivid detailed upper mids/treble (nearly analytical quality, can even get a touch hot with some recordings but never harsh/peaky/sibilant); also lower mids do lack some body. SS reminds me A LOT of Titan 1, a lot, except Titans have mids a bit more forward. I prefer GT100s over Titan 1, btw.

Click to expand...

http://www.head-fi.org/t/586909/the...-iems-by-twister6-pg-1949/29220#post_11668323

DannyBai's impressions

Sound is excellent all around. Treble sticks out for me. Reminds me of the Titan. I think twister also noticed this. Bass sounds a bit flabby to me but not boomy. Vocals are forward and nice. Overall this is one heck of a bargain. - DannyBai

Click to expand...

http://www.head-fi.org/t/586909/the...-iems-by-twister6-pg-1949/29280#post_11678509



Quick comparisons

Vsonic VSD5



The VSD5 is bassier, both mid and sub-bass. By a decent margin. The GT100s has better clarity, and not just clarity by way of a lot of treble either. The Gt100s is more detailed with better instrument separation. VSD5 has a bigger soundstage, but the GT100s has excellent, excellent depth. VSD5 is on the dry side, whereas the GT100s is more liquid. I find both to be very engaging, but damn if I don't prefer the Macaws.


Ostry KC06



Doing some back-and-forth with the GT100s and the KC06. They're priced similarly, and both IEMs are made by birds, so maybe a good comparison. First thing you notice is, as is becoming par for the course, the GT100s is clearer. It makes what is generally considered to be a very clear earphone(the Ostrich) sound a little bit on the stuffy side, exacerbated by the better instrument separation of the Macaws.

A few posts back I said "These things are just soooo clear and they have an almost audible black space between instruments, if that makes any sense", and in reading Twister's review I noticed he experienced the same thing but maybe said it in a way that makes better sense.

You literally hear layering airy effect between sounds.

Click to expand...

The KC06 is warmer, bassier, and places vocalists much closer to you. The GT100s has a stronger treble response.


Pros:
Excellent build quality
Very detailed, very clear, vivid and spacious sound
Filter tuning system
Value

Cons:
Potentially uncomfortable
Somewhat difficult to drive from a phone(admittedly I like to use high volumes at work, the gym, the coffee shop etc., so YMMV)

6/10

[color=rgba(0, 0, 0, 0.8)]

​

[/color]

 

[color=rgba(0, 0, 0, 0.8)]Macaw GT100s Review: Unforgivingly Detailed[/color]

[color=rgba(0, 0, 0, 0.8)]Macaw is a Chinese IEM company that specializes in building earphones. Currently, they have chosen to stay well within the boundaries of “budget” earphones. At a glance, however, you wouldn’t even know it.[/color]
[color=rgba(0, 0, 0, 0.8)]You can find the GT100s here on Penon Audio for $55.[/color]
[color=rgba(0, 0, 0, 0.8)]Note: Some people may have read my previous review of this IEM or seen my comments about them. I was rather unflattered by them the first time around. However, since I’ve acquired more powerful and resolving sources and amplifiers, I’ve decided to give these another chance. My suspicions regarding my previous source setup being inadequate were confirmed not even 30 minutes into my first listening session. To summarize, my previous impressions on these IEMs are invalid as I did not have the hardware necessary to drive the GT100s at its full potential.[/color]
[color=rgba(0, 0, 0, 0.8)]Disclaimer: This review is based upon a sample unit provided to me by a manufacturer or distributor in exchange for my honest opinion and un-edited words. I do not profit in any way from the writing of the review. I would like to thank Macaw and Penon Audio for sending me this review unit.[/color]
[color=rgba(0, 0, 0, 0.8)]Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.[/color]
[color=rgba(0, 0, 0, 0.8)]My ideal sound signature would be an extended sub-bass with a leveled, but textured, bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.[/color]
[color=rgba(0, 0, 0, 0.8)]Source: The GT100s was powered like so:[/color]
[color=rgba(0, 0, 0, 0.8)]AP100 3.5mm out -> FiiO A5 (low gain) -> earphones[/color]
[color=rgba(0, 0, 0, 0.8)]or[/color]
[color=rgba(0, 0, 0, 0.8)]HIFIMAN Megamini 3.5mm out -> earphones[/color]
[color=rgba(0, 0, 0, 0.8)]All music was served as MP3 @320Kbps or as FLAC.[/color]
[color=rgba(0, 0, 0, 0.8)]The GT100s cannot be driven well without a fairly powerful source. I recommend a dedicated DAP at a bare minimum, as I did not find any of my smartphones to be sufficient in driving the GT100s without a loss in quality and an inability to reach higher volumes.[/color]

[color=rgba(0, 0, 0, 0.8)]Sound Signature[/color]

[color=rgba(0, 0, 0, 0.8)]Initial Impressions:[/color]
[color=rgba(0, 0, 0, 0.8)]Given the GT100s’ rather unique sound signature, it was definitely not very pleasant to listen to at first. Coming from the Advanced Sound Model 3 and Meze 99 Classics, I definitely needed a couple hours to burn my brain in. Thank goodness I waited before passing judgement on them, as they really grew on me. The bass is linear, and extends far down with a slight bump up in the sub-bass to increase the rumble of the IEM. The mids are slightly recessed behind the treble, which controls the GT100s’ presentation. The treble itself is quite well extended, but does a have a certain harshness to it and can sometimes border on sibilance. After a period of adjustment, however, you should be fine.[/color]
[color=rgba(0, 0, 0, 0.8)]The GT100s has three tuning filters. Gold for bass, black for treble, and silver for neutral. The gold filter adds a slight amount of warmth to the lower mids and bass that many listeners may enjoy. The black filter places a little-bit more emphasis on the treble, but in turn makes the mids sound a bit more shouty and hollow-sounding. This is my least favorite filter.[/color]
[color=rgba(0, 0, 0, 0.8)]Given the rather minute differences between each filter, I will be completing the rest of my analysis using the neutral filters.[/color]
[color=rgba(0, 0, 0, 0.8)]Treble: Songs used: White Flag, Midnight City, Outlands[/color]
[color=rgba(0, 0, 0, 0.8)]The GT100s’ treble can be summarized quite well with a single phrase: brutally honest. It doesn’t care whether or not you want to hear each and every bit in the song; it will simply show it to you. The vast majority of the time, this amasses itself in pleasant ways. White Flag and Midnight City’s micro-details were dragged out from their hiding spots by the GT100s’ dynamic drivers. The same could be said for Outlands. The violins had fantastic separation and placement, giving the song a sense of air. There were a couple instances during White Flag where I would say that the treble did come across as a tad harsh. That’s not veiled criticism, I literally mean that it only sounded a little bit harsh.[/color]
[color=rgba(0, 0, 0, 0.8)]I know that Flagpole Sitta is a song that I use in the mids section, but it makes very good use of high-hats. As such I feel that is relevant for me to mention that the GT100s has the second-best presentation of high-hats and cymbals I have ever heard. Period. I can hear each hit of the cold metal against the drummer’s worn sticks. Frankly, it’s amazing. Seriously, if you buy these go to 2:10 of the song and listen to the high-hats in the background and you will see what I am talking about.[/color]
[color=rgba(0, 0, 0, 0.8)]Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams[/color]
[color=rgba(0, 0, 0, 0.8)]The mids of the GT100s are rather flatly presented, if not a bit coldly. It’s a nice change of pace from the constant onslaught of mainstream warm IEMs. The guitars of Flagpole Sitta and Jacked Up have a nice crunch to them and are quite clear in the mix.[/color]
[color=rgba(0, 0, 0, 0.8)]Male vocals sound a bit thin, but are still well-articulated and have an overall good presentation. If the song you are listening to has not been treated for sibilance, you will definitely hear it. A good example is comparing Weezer’s older albums with their new ones. On their older ones you will hear a slight sibilance, while their newest one, White Album, has no signs of sibilance at all.[/color]
[color=rgba(0, 0, 0, 0.8)]Female vocals are presented almost perfectly, with a good body to them. Even traditionally darker voices like that of Garbage sound good.[/color]
[color=rgba(0, 0, 0, 0.8)]Bass: Songs used: Lights(Bassnectar Remix), Gold Dust, In For The Kill (Skream Remix), Leave Me[/color]
[color=rgba(0, 0, 0, 0.8)]Bass is quite linear, with the exception of a small boost to the sub-bass region, somewhere around 20–80Hz. This means that you won’t quite get a thud out of bass-kicks, but you will get a good amount of rumble out of bass-drops. While Lights did leave something to be desired in both impact and rumble, I found Gold Dust to perform much better. There was a moderate amount of kick with a good amount of rumble. The bass is quick and clean, leaving no boomyness in its wake.[/color]
[color=rgba(0, 0, 0, 0.8)]In For The Kill provided the GT100s with a stage in which it could demonstrate how well it extended down. The GT100s outperforms essentially all other IEMs I own on this song, as the mid-bass doesn’t cloud up the lower register, making the dynamic sub-bass easy to pick-out. Two IEMs which didbeat the GT100s are the Rose 3D-7 and Accutone Pisces BA (both of which are quite a bit more expensive than the humble $55 GT100s).[/color]
[color=rgba(0, 0, 0, 0.8)]Clarity: Songs used: Throne, Map of The Problimatique, I’m Not Alright[/color]
[color=rgba(0, 0, 0, 0.8)]Throne performed very well, with no distortion at all. A smooth portrayal of the vocals, convincing drum kicks, and resolving treble-bound details all made for a very enjoyable experience.[/color]
[color=rgba(0, 0, 0, 0.8)]I’m Not Alright went similarly, with only a small number of lost details during the chorus. The background violins, which live in the upper mids, faded in and out of intelligibility.[/color]

[color=rgba(0, 0, 0, 0.8)]Packaging / Unboxing[/color]

[color=rgba(0, 0, 0, 0.8)]Macaw encased the GT100s in some of the most complex packaging I’ve ever seen on an IEM. While it did take a couple minutes to figure out at first, this wasn’t a big issue to me. One thing I would like Macaw to change is how tightly they pull the cables when placing the GT100s in its holder. As it stands, the packaging could put strain on the cable before the customer ever even holds their shiny new IEM.[/color]
[color=rgba(0, 0, 0, 0.8)][/color]
 

[color=rgba(0, 0, 0, 0.8)]Build[/color]

[color=rgba(0, 0, 0, 0.8)]Construction Quality[/color]
[color=rgba(0, 0, 0, 0.8)]For $55, the GT100s’ build quality is nothing short of impressive. The driver housings are built from solid stainless steel. The Macaw logo is embedded behind a layer of glass on both of the housings giving them a premium look. Every part of the driver housing, from the filters to the stress relief, feels solid. The downside of a very durable stainless-steel body is that is heavy. You can really notice the heft of these in your hands.[/color]
[color=rgba(0, 0, 0, 0.8)]The cable is fairly basic, but given the luxurious build of the rest of the IEM, I give it a pass. There is a single circular button on the right housing’s cable. It acts as a pause/play/skip button and has a microphone inside. The button is also built from aluminum and glass and feel very nice to press. I don’t notice any out-of-the-ordinary microphonics. A chin-slider would be a nice addition though.[/color]
[color=rgba(0, 0, 0, 0.8)]Comfort[/color]
[color=rgba(0, 0, 0, 0.8)]As I mentioned earlier, the GT100s is heavy. That’s not necessarily an issue though, as it is meant to be worn over-the-ear style. This allows you to offload much of the downwards drag onto the top of your ears. I did not notice any discomfort due to sharp-edges or weight during my standard three-hour listening session while sitting down. Unfortunately, you cannot lay down with these while on your side.[/color]

[color=rgba(0, 0, 0, 0.8)]Accessories[/color]

[color=rgba(0, 0, 0, 0.8)]The GT100s comes with a good number of accessories. Inside the box you will find:[/color]
[color=rgba(0, 0, 0, 0.8)][/color]

1. 3x pairs of silicone eartips
2. 2x pairs of memory foam eartips
3. 2x pairs of tuning filters (1x black, 1x gold)
4. 1x carrying pouch

[color=rgba(0, 0, 0, 0.8)]The carrying pouch included with the GT100s is one that I really, really like. I do not think it is made from genuine leather, but it is certainly still convincing. It is soft and spacious. Emblazoned on the inner-lip of the pouch’s flap you can find the classy phrase “Listening & Thinking” — something I do quite often.[/color]
[color=rgba(0, 0, 0, 0.8)][/color]

[color=rgba(0, 0, 0, 0.8)]Summary[/color]

[color=rgba(0, 0, 0, 0.8)]The GT100s makes for an excellent departure from mainstream V-shaped tuning while not sacrificing long-term listenability. When powered correctly, the GT100s easily outclasses its peers in terms of clarity, sound-staging, micro-detail retrieval, and accurate presentation. While the cable leaves something to be desired, the audiophile looking for something a bit different will certainly enjoy the GT100s.[/color]

---

Before I start my review, i would like to Thank Macaw for a review sample of GT100s in exchange for my honest opinion.  The review sample was actually received from Penonaudio where it's currently on sale for $69: http://penonaudio.com/Macaw-GT100s

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Sub $100 headphone market has been heating up for the last few years with a lot of very impressive releases, even priced as low as $10-$20.  And it seems that a number of manufacturers continue to push the envelope, trying to introduce products with not just a great sound but also an upscale design and accessories.  I just had a pleasure to test one of such products that literally left me in disbelief that it cost only $69.  You probably already know what I’m going to say next – we are dealing with another Giant Killer here!  As you can see, I'm very excited about this new GT100s headphone model, and here is why.
 
I usually start with a packaging description, but have a little confession to make.  Often when I receive a new pair of headphones, I take the box apart to play around with a product first, and then put it back together to take unboxing pictures.  As soon as I looked at the plastic box GT100s arrived in and saw a walkthrough guide with 8 detailed pictures of how to take it apart, I knew I probably won't be able to put it back together as neatly, and started to click those pictures away!  It's clear this company put a lot of thought into the design, accessories, and even unique packaging with plastic stands/holders to keep GT100s shells up on a display level.
 
Beside unboxing instructions on the back of the box, there was also a message of “The first inverted dynamic driver earphone”.  I thought I read this claim before from another headphone maker, but it doesn’t really matter since I usually don’t pay too much attention to marketing hype and rely on my own eyes and ears to judge the product.  Careful examination of the spec also revealed a few clues, including a lower sensitivity at only 100dB which means it will require some boost in volume to drive them.
 
Unboxing.
 

 

 

 

 

 

 
 
Taking the box apart was fun, and once I was finished with GT100s and all the accessories out in the open, I quickly realized that based on just looks it punches way above its price point.  Another conclusion I drew right away was about similarities with RHA T10i headphones, in terms of nearly identical bicolor hybrid silicone eartips (S/M/L with a black core), a metal holder fitted with 2 pairs of foam (non-Comply) eartips, and a stainless steel narrow plate with 2 sets of high quality screw-in filters.  These were definitely NOT a filler or a budget accessories thrown in together to make it look like a premium product.
 
One accessory that stood out for me was a neat leather case that looked like a wallet.  It had a nice quality soft leather with a wrap strap going all the way around where you just tie it to secure case closed.  It even had a little round button emblem in the corner which comes apart when you unscrew it, probably symbolizing a nature of replaceable filters.  This is not a hard case, but considering tough build quality of these IEMs – you don’t need too much protection.
 
Accessories.
 

 

 

 

 

 

 

 

 
 
Looking closer at the design, the first thought that popped into my head was: DITA!   I know it’s crazy to compare $69 pair of GT100s to $650-$1k pair of well known flagship IEMs, but a nature of a solid stainless steel shell build, curved molded strain relief attached to it, circular stainless steel y-splitter – all that reminded me a bit of scaled down DITA the Answer.  According to Macaw, they used a MIM - metal injection molding production technique, coincidentally found on RHA T10i as well, which begs a question if Macaw could possibly be their OEM? 
 
Starting with a gold plated TRRS connector plug, it has a short and slim metal housing with a trimmed strain relief; housing is probably a bit too short for big sausage fingers.  Cable has TPE rubbery coating which unfortunately is a bit stiff and has a memory effect.  It’s not too thick or too thin and not springy, but memory effect is there.  Y-splitter has a neat little round “tablet” shape, and right side of the wire going to the shells has a similar diameter in-line remote with a trimmed strain relief on each side. 
 
That GT100s remote was definitely something I couldn’t keep my hands off.  There is a mic pinhole on a side, but the button is actually the whole tempered glass piece with a logo inside of it.  It’s a single universal button for Play/Pause/Call and skip music with double click.  Call quality was good and I enjoyed using the button to control my FiiO DAPs supporting in-line remote operation.
 
This tempered glass round button with Macaw emblem inside of the remote is nearly the same (just a mm or two less in diameter) as tempered glass pieces on outside of the headphone shells.  The shell has a brushed stainless steel finish with cable attached to a curving molded strain relief that naturally goes around/behind your ears and nearly eliminates the microphonics.  At the base of the cable connection, there is a stamped L/R marker, and in the center of the shell there a pinhole port to pump the air out from their single dynamic driver.
 
For sure, the highlight of this design is a removable filter, and trusts me – it’s not a gimmick.  I did recently reviewed KZ ED9 with interchangeable filters, but what you see here is a lot higher quality with a more robust design, down to a rubber gasket to keep it tight without coming loose/undone when you replace eartips.  Typical of interchangeable filter theme from other manufacturers, you have a default neutral silver filter, a treble enhanced gold filter, and bass enhanced black filter, and as confirmed later – all with an added contribution to a sound shaping.
 
One biggie I have to point out, and this could be a deal breaker for some people, GT100s are heavy.  Solid stainless steel design with a tempered glass inserts does come at a price of additional weight.  Just for the reference due to all metal-build similarities, DUNU Titan1 shells weight 8g while GT100s is 16g, double the weight.  If you take into consideration a shallow insertion fitment, limited mostly by the length of a filter/nozzle, you really need to be careful with a selection of eartips in order not only to fine tune a sound but also to keep these earpieces tight in your ears.  It’s not the end of the world and I got used to it after awhile, but I did have to go through a number of eartips settling on either T500 Comply or original UE900 large size.  I wasn’t too fond of included foam tips because they were soft, and Comply offered a firmer expanded fitment.  I also had success with Titan large eartips (hybrid tips you can find cheap on Lunashops), but for me personally UE900 eartips were the best due to a firm large rounded cap.  Also, with a larger eartips and a tighter seal, I experienced a little bit of driver flex in my left earpiece when using UE900 tips, while Comply was fine.
 
Design details.
 

 

 

 

 

 

 

 

 

 

 
Fitment (w/eartips)
 

 

 

 
 
There is no doubt these are high build quality IEMs with a rather unique design and original accessories.  There are some caveats with an extra weight that can give your ears a workout, and I personally wouldn’t recommend jogging or doing some intense running or jumping while wearing these.  But the earpiece weight is manageable and will “disappear” as soon as you hit Play and start listening to their sound.
 
First of all, I did mention at the beginning these are not efficient due to a lower sensitivity which requires cranking up volume by a little bit.  It is true, and I found that I had to raise a volume by about 10 ticks in most of my DAPs, but unlike some other low sensitivity IEMs that require amping, GT100s sounded great even driven from Low Gain setting.  As a matter of fact, I was even able to drive it without a problem straight from my Note 4, though did have to raise volume closer to the top.
 
Starting with a base Silver Filter, I found a balanced signature with a bright detailed airy sound and slightly recessed mids.  It definitely has “characteristics” of titanium driver with a great bass and bright/detailed uppers mids/treble.  Sometimes it feels like you are listening to hybrid IEM with DD driving the bass and BA driver controlling bright and detailed uppers mids/treble.
 
I found extension at both ends of the spectrum to be quite good.  Soundstage had an excellent width and depth, definitely above average.  Also, a very good separation of instruments and vocals, sound never becomes congested, no matter how complicated music piece gets.  You literally hear layering airy effect between sounds.  Imaging is great as well, with a convincing placement of instruments and vocals in space.
 
Bass extends down to an intelligent sub-bass that comes out to play only when called upon.  Sub-bass has a smooth textured layer that adds a nice supporting weight underneath of fast mid-bass punch. The balance between sub- and mid-bass was quite good.  Bass is well controlled, tight (got much better after 50hrs of burn in), no bloat or spillage into lower mids.  Here, it's all about quality rather than quantity.
 
With Midrange you will find lower mids to be thinner which takes away from mids body, but it's compensated by a very detailed upper mids which I found to be a bit recessed relative to low end and treble.  The clarity and retrieval of details is great, almost on analytical level without being harsh or grainy.  Vocals sounded great, though lack of lower mids warmth takes away from organic feeling.
 
Treble is crisp, detailed, with a great extension.  It’s absolutely non-fatigue, though can get a bit hot with some of the tracks at higher volume.  As a matter of fact, these are probably among one of my favorite bright detailed non-fatigued headphones I heard in a long time with an excellent tight low end and bright detailed upper mids.  Considering I'm not a big fan of bright analytical sound and lately been preferring a thicker warm detailed sound, it says a lot about this compliment.
 
Trying it with different filters, I found Gold Filter setup to have a touch less sub-bass, and a little brighter upper mids with a slightly better treble extension.  Sound became more neutral, but difference was still subtle to my ears.  With Black Filter, I found a little more sub-bass and smoother upper mids/treble with a little less sparkle.  Overall, I found filter changes to be subtle, focusing more on fine-tuning the sound rather than changing it drastically.
 
GT100s next to Titan 1
 

 
 
Compared to my other IEMs, here is what I found while using silver filter.
 
vs GT100s, Titans 1 has a stronger mid-bass punch, a more upfront upper mids (the same thin lower mids), upper mids/treble are a bit more grainy/harsher and sounds a bit less organic in comparison, treble has a little more extension, soundstage has the same depth but Titans are a little wider.  Plus, you get a full isolation with GT100s vs none with Titans.  But overall, sound has very similar "titanium" driver characteristics.
 
vs GT100s, IM03 has a slower mid-bass, with a little bloat in comparison, that spills a bit into lower mids, deeper sub-bass, thicker lower mids, warmer/smoother upper mids which are less detailed, mids are more upfront, treble has similar extension, staging has less width/depth.  Overall sound is warmer, smoother, and not as detailed.
 
vs GT100s, KC06A has a deeper sub-bass, stronger mid-bass punch, thicker lower mids, less detailed upper mids, slightly less treble extension.  When it comes to soundstage, it has less width and a lot less depth.  Overall sound is smoother and not as detailed/revealing.
 
vs GT100s, B3P1 is more neutral, warmer, with a smoother sound, a similar soundstage width but a bit less depth, a little more sub-bass, but low end is not as tight.  Thicker lower mids, smoother and less detailed upper mids, and a similar treble extension.
 
vs GT100s, A83 has a little more mid bass and overall low end is higher definition and more articulate, lower mids are a bit thicker, upper mids are a little smoother and more forward, and it has a similar treble extension.  Same soundstage width but GT is a bit deeper.  Overall, A83 has a more balanced and fuller body sound.
 
Conclusion.
 
I found Macaw GT100s to be a very surprising gem!  Everything from a top notch build quality to a selection and quality of accessories including those quality filters screams a $200 headphone package.  Tuning is not for those who crave smooth warm sound, but rather for audiophiles or music lovers who want brighter sound with more details and bigger soundstage without paying a price of settling with a harsh ear-fatigue sound.  The sound can get a bit hot and could come close to a threshold but never reaches sibilance level or becomes unbearable during extended listening session.  The only thing I wish for Macaw to consider moving forward is to optimize ergonomics of the shell, making it lighter and smoother.  With a shallow insertion, right at the base of the shell where you attach the filter I wish they wouldn’t use that raised angled part which can hurt your ear a bit when you push on the shell for a better fitment.  Of course, we all have different inner/outer ear anatomy so your experience will vary, and as a matter of fact with a right selection of eartips (Comply probably being the best bet for many people) – fitment is quite manageable.  What it all comes down to is an excellent build quality and a fantastic tuning that punches in value easily at 2x-3x of its price.  Definite highly recommend these, but want everybody to be aware of fitment and extra weight.