My initial introduction to the Advanced Sound Group was only a few months ago with a review of their new GT3 tunable IEM. Fast forward to present day, and they’ve taken the same design, reworked the internals, and released a very different sounding IEM. When Peter Yoon contacted me and told me about their “GT3 Superbass” , for a moment I almost paused (strong bass has never been my preference), but Peter and his team had done such a nice job on the original GT3, I was interested to see what they had achieved. So lets take an in-depth look at the GT3 Superbass and find what changes they’ve made from the original GT3 .
ABOUT ADVANCED SOUND
The Advanced Sound Group formed following a successful 2015 Kick-starter campaign for their M4 earphone. Since then the New York based company has grown, and so has their product line. They now have other IEM’s, a full sized planar headphone, wireless earphones, DACs and amps, and a range of accessories. They have a loyal following of musicians as well as everyday people as customers, and while their tag-line states “Designed for Musicians”, its nice to see their goal is to blend the market for both. In their own words “We are focusing on staying forefront with the latest proprietary audio technology, while continuing to explore creative ways to allow everyone to experience the audiophile-grade sound. We have an open mind and open doors for new ways to collaborate with musicians, audio engineers, manufacturers and brands – as we strive to mature into a platform where the advanced sound converge.”
The Adv-Sound GT3 Superbass IEM that I’m reviewing today was provided to me freely as a review sample. Peter has asked me to keep it for my personal use, or for follow up comparisons, and I thank Adv-Sound for this. The retail price at time of review is USD 199.
If you haven’t read any of my reviews, I suggest starting here, as it will give you an insight into my known preferences and bias.
For the purposes of this review – I’ve used the GT3 Superbass straight from the headphone-out socket of many of my portables, but predominantly the FiiO X7ii, X5iii, M7, and my iPhone. I have tested them both amped (Q1ii, Q5, XRK-NHB, and E17K), and straight out of the DAPs listed.
In the time I have spent with the GT3 Superbass, I have noticed no change to the overall sonic presentation (break-in). This is a purely subjective review – my gear, my ears, and my experience. Please take it all with a grain of salt – especially if it does not match your own experience.
The GT3 Superbass arrived in a 128 x 180 x 55mm “book style” box with retail sleeve. The outer sleeve is quite detailed with photos, a frequency response graph, specifications and a lot of detail about the product (almost identical in style to the original GT3). Once again, they’ve put a lot of thought into this, and while the front is simple and elegant, the rear has a plethora of information.
The inner box is matt black with a foam insert for the GT3 IEMs and tuning filters, and a large carry case for the cables and accessories.
The total accessory package includes:
- 1 pair of Adv-Sound GT3Superbass dynamic driver IEMs
- 3 interchangeable tuning filters
- 1 x 3.5 mm single ended to MMCX silver plater copper earphone cable
- 1 x 3.5 mm single ended to MMCX 3 button mic/volume/remote earphone cable
- 3 pairs of foam tips
- 3 pairs of silicone single flange tips
- 3 pairs of silicone dual flange tips
- 1 large zippered carrying pouch (approx 120 x 85 x 40mm)
- 1 leather magnetic cable tie
- Multi-language user guide
THE TECHNICAL SPECIFICATIONS
|Approx price||$199 USD|
|Type||Single DD IEM|
|Driver||Ultra-thin (6μm) mass-coil 10mm dynamic driver|
|Freq Range||10Hz – 40kHz|
|Impedance||84Ω +/- 15%|
|Sensitivity||95 dB +/- 3dB (at 1 kHz)|
|Cable Type||1.5m SPC and 1.2m with on cable controls|
|Cable Jacks and Connectors||3.5mm gold plated with standard MMCX|
|Weight||33 grams (including SPC cable and tips)|
|IEM shell||Black matte coated stainless steel|
The graphs I use are generated using the Vibro Veritas coupler and ARTA software. Ken Ball (ALO/Campfire) graciously provided me with measurement data which I have used to recalibrate my Veritas so that it mimics an IEC 711 measurement standard (Ken uses two separate BK ear simulators, we measured the same set of IEMs, and I built my calibration curve from shared data). I do not claim that this data is 100% accurate, but it is very consistent, and is as close as I can get to the IEC 711 standard on my budget. I suspect it is slightly down at around 9-10 kHz, but seems reasonably accurate through the rest of the spectrum.
I do not claim that the measurements are in any way more accurate than anyone else’s, but they have been proven to be consistent and I think they should be enough to give a reasonable idea of response – especially if you’ve followed any of my other reviews. When measuring I always use crystal foam tips (so medium bore opening) – and the reason I use them is for very consistent seal and placement depth in the coupler. I use the same amp (E11K) for all my measurements – and output is under 1 ohm.
The graphs are provided merely as a point of discussion, and later in the review I’ve included comparisons to other IEMs for similar reference.
The graph shown is using the red filter. Later in the review I’ll discuss the other tuning options. Channel matching is good.
The GT3 Superbass has a slightly angled bullet shape and is designed to be used over ear (at least it is with the SPC cable and preformed ear hooks). The GT3 consists of a 2 piece stainless steel coated (matte black) shell (the seam is beautifully engineered and not prominently visible), with a screw on filter which forms the nozzle and allows you to change the tuning. The GT3 Superbass measures ~12mm in width, and ~24mm in length (including the nozzle).
The outer face of each IEM has the shortened model number (GT3) printed in white, and the inner face has the company name (ADV). At the top and to the rear of the GT3 is the MMCX housing which has a small red dot on the right hand socket for easy identification (the left has none). There is a single DD driver vent or port at the bottom of each casing. The body is nicely cylindrical and very smooth, and with the face angled inward is very comfortable to wear.
The tuning filters are threaded into the front of the IEM, and once in place it creates a nozzle (on a slightly forward angle) ~5mm from the body. The nozzles are ~6mm in diameter and have a mesh end and very good lip.
There are 2 cables included – a silver plated copper and a cable with mic and on-cable controls.
The SPC cable is 1.5m, quad braided, and has preformed flexible over-the-ear loops at the MMCX connectors. The sheath has quite low micro-phonics, and these can be all but eliminated by the use of the included neck cinch, and some positional management with clothing. The y-split is a metal cylinder which for me sits below my sternum. There is good strain relief on both sides of the Y-split and again at the jack. The jack is 3.5mm, straight, and is smart-phone case friendly. It is gold plated. The cable appears to be extremely well made and aesthetically looks like it would sit equally well on a much more expensive ear-phone.
The second cable is slightly shorter (1.2m), has the same preformed ear-loops, a smaller y-split and smaller right angled jack housing. The cable has controls on the right side, which hang down at approx chin level (so ideal place for a microphone). The control unit consists of a microphone with 3 button panel. The bottom button controls play/pause (single click) next (double click) previous (triple click). The middle and top buttons control volume up and down. All three buttons work universally on both Android and iOS (tested on my iPhone and Android based DAPs). The microphone reception is clean and clear. Below the y-split the cable is cloth covered, and the whole cable has very low micro-phonics. There is also a cinch which can be placed above or below the control unit.
Overall I’m very impressed with both cables, and the icing on the cake is a nice magnetic leather loop for cable control. And as far as the entire build goes – I am very impressed, and can completely understand why Advanced Sound gives the GT3 Superbass a 3 year warranty. These are incredibly well built IEMs
Internally the GT3 uses a single 10mm dynamic driver, but the design is quite different to the original GT3. Peter was very open with explaining the differences, what they wanted to achieve, and how they went about it. Their first step was using a different pure copper coil which is a lot heavier than the original model. This stronger coil is the main reason for the increase in impedance (84 ohm now vs the original 32 ohm). The stronger voice coil then needed a thinner diaphragm (now around 6μm), and Adv Sound actually trialled more 10s of different iterations of the driver to eventually come up with Superbass. The combination of heavier coil and thinner diaphragm allows Adv Sound to increase the vibration stroke of the diaphragm to move more air. This allows more sub and mid-bass control whilst retaining a harmonious mid-range. The other internal change is a different design of the driver cover to route the corresponding airflow differently.
FIT / COMFORT / ISOLATION
Isolation is above average considering the GT3 is a vented dynamic, and most public transport noise should be isolated, with the remainder masked by your music. Of course this does depend on how good your tips are, and what sort of seal you get.
Fir and comfort can vary from person to person, and for me personally the GT3 Superbass (like the original GT3) is very comfortable, and especially with the foam tips I’m using. The simple bullet design, combined with the slight angle toward the nozzle and the over ear fitting, is very comfortable. They sit within my outer ear, and I can forget they are in at times. I have slept with them intact, and woken hours later with them still there and no discomfort.
The nozzles have a very good lip, and with the standard sizing, I had no issues fitting Spiral Dots, Spin-fits, Ostry tuning tips, Symbio Mandarines and Sony Isolation tips. Their own included tip included a pretty good set of flat dual flange wide bore tips, and these also worked pretty well – as did the included Crystal foams). My tip of choice for the GT3 Superbass depended on the filters – but was either Symbia Mandarines or Shure Olives (more on that down the page – it was with different filters).
This is always a hard one – as there are often many options, and without measurements, it is very easy for our brains to throw a filter over everything we hear. Because of this, we can grow quickly accustomed to an IEM’s tonality and lose sight of its performance against the other options.
The front filters double as the nozzles. They are 7mm in length (5mm exposed when fitted), 6mm in diameter with a mesh over the nozzle and good lip. They also have a threaded screw to fit the front of the GT3 Superbass, and are also fitted with a rubber washer to maintain seal and integrity. They are pretty easy to change out.
The documentation included with the GT3 Superbass describes the filters as treble (red), reference (silver) and bass (black). Advanced Sound’s graph shows the main difference being less than 5 dB from each filter and in a pretty narrow band between 2-5 kHz. This of course would mean that the bass quantity doesn’t actually change, and the perceived difference is solely based on the changes in upper mid-range. The easiest thing for me to do was to measure them myself on my own rig, and the graph is shown below.
Sure enough, while my graphs showed differences between the measuring systems, the main change was between 2-6 kHz, and the biggest changes were between 4-5 kHz and maximum delta approx 5dB per filter. The differences are noticeable – but they are not extreme. If I use (for example) the red filter in one ear and silver filter in the other, within a few minutes my ears adjust and it sounds like a perfect stereo image. The silver and black, have slightly more difference. The largest perceivable difference is between red and black. I mentioned in my review of the GT3 (original) that I thought there was an opportunity to vary the filters a lot more and have very distinct signatures – but it appears that this is not yet part of Adv Sound’s thinking (which I personally feel is an opportunity missed). The good thing is that this can be rectified later if they do want to expand the filter range (LZ recently did exactly this with their A5), and the new filters they released were able to really extend the versatility of a very good earphone.
All 3 filters currently deliver a much flatter frequency response than the original GT3, with varying levels of upper mid-range. The bass has a linear rise from lower mid-range to sub-bass, and has very driver control. Sub-bass is elevated compared to mid bass and upper mid-range. Compared to the mid-range, the lower treble has a lot less emphasis, and this combined with the elevated bass gives a warm and slightly dark overall presentation.
The mid-range on the GT3 Superbass – for my preferences – is the strong point. Very few manufacturers seem to get this right in my opinion, and Adv Sound with the GT3 Superbass has nailed it. For me a great mid-range and upper mid-range has a slight valley around 1 kHz (wide and shallow), then a gradual but smooth rise to ~3 kHz. This creates a natural tonality and aids both euphony, and negates dissonance.
Weight with both female and male vocals is extremely good. Unfortunately for me, the lack with the Superbass GT3 is in the lower treble which is quite shelved. The reduction compared to both mids and bass creates a very smooth sound, but a lot of the detail of instruments like cymbals is diminished.
When I first reviewed the original GT3 I had noticed that the filters looked similar to Trinity Audio’s original line, so I dug out my Atlas, and sure enough – a perfect fit. Trinity used to change the bass using tiny pinholes in the nozzles, and then (on some models) would use damping to change the upper mids and lower treble. Trinity used to have quite V shaped tunings, so I suspected most of their filters might not work but I was interested to see how they would directly compare to the existing GT3 Superbass filters. The graph below shows the gold, purple and black Trinity filters compared to the Red GT3. Ultimately this may suit someone who wants more variation with bass – but does not want to play with EQ. I didn’t show the Trinity red and orange filters which add even more bass (not to my taste).
When combined with the Shure Olives (different diameter) I got a perfect fit, and great isolation, and the purple or gold filters are probably a little closer to my preferred sonic signature. I’ll continue the review with the GT3 red filters (my preference of the GT3 default options – black with EQ, but we’ll come to that later), but I wanted to mention this – mainly for Advanced Sound as I think it will give them more scope for future changes.
My testing for this section was done with the FiiO X7ii (AM3A module), no EQ, and Symbio Mandarine tips with the silver reference filters. I used the X7ii simply because it provides both a very transparent window to the music with low impedance, and also more than enough power. No EQ was used.
For the record – on most tracks, the volume level on the X7ii (paired with AM3a) was ~60/120 Single Ended (on low gain) which was giving me an average SPL around 65-75 dB (track dependent). Tracks used were across a variety of genres – and can be viewed in this list https://www.head-fi.org/f/articles/brookos-test-tracks.17556/
- Sub-bass – very good extension, elevated and quite prominent. Has a lot of rumble even at lower listening levels, and for my personal tastes it is a little over-done, but bass lovers will enjoy this.. With sub-bass dominant tracks (like Lorde’s Royals) there is bleed (or masking) into the lower mid-range.
- Mid-bass – good impact, and slightly stepped back compared to the sub-bass. Still has quite visceral thump – but this is pretty good quality and the definition is there (no real distortion). With hip-hop (Eminem), the bass is still quite clear, but definitely hits harder than most of my current earphones.
- Lower mid-range – there is a slight recession compared to mid-bass, but it is gentle, and there is no real distance (in fact vocals sound as if they are perfectly placed – not too far, not too close). Male vocals have great presence, and female vocals have just the right amount of euphony.
- Upper mid-range – elevated compared to lower mid-range, which really helps add that sweetness in the presence area for female vocals. I really can’t fault the upper mid-range at all – its cohesive, and tonally brilliant (although warm and smooth – mainly ue to the shelved treble and enhanced bass).
- Lower treble is recessed – and this is one of the main reasons the GT3 Superbass has a quite warm and smooth signature. The area from 6-10 kHz is very recessed compared to both sub-bass and upper mid-range (although there does seem to be a little bump around 9 kHz which my Veritas does not quite pick up. Extension beyond 10 kHz seems to be pretty good despite the recession. My biggest issue is with 7-8kHz – the area which gives cymbals their brilliance and overtones. My main test track for this is Pearl Jams “Elderly Woman …..” and the GT3 Superbass renders the cymbals, but they are very much in the background. The good news is that Vedders vocals are heavenly – it just seems that something is miissing from the track. People sensitive to treble will love this.
- Upper treble – seems to be well extended with no huge peaks. Its hard for me to judge this area, because my hearing tops out around 14kHz nowadays, and the measuring equipment is not accurate enough from about 9 kHz up. No signs of brittleness.
Resolution / Detail / Clarity
- Clarity is OK, and there is good detail in some of my usual test tracks. With Nil’s Lofgren’s “Keith Don’t Go” (acoustic guitar), the micro details such as finger movements on the fret-board are audible, but somewhat muted. On tracks like Dire Straits “Sultans of Swing”, some of the micro details which usually stand out are very subdued – masked by the bass guitar. I know the detail is there – its just in the background quite a bit,
- Cymbals hits (especially hi-hats and crash-cymbals) are there but quite muted, and the trailing decay is very short and again not prominent.
- Portico Quartet’s “Ruins” is a good track for checking the balance on drumstick clicks, hi-hat taps and general cymbal decay, and again the GT3 Superbass does pick up the detail but again its quite muted. Cymbal brushes (which are normally delicate and sustained) are distant and quite hard to pick up.
- Directional queues are on the whole pretty good and transients with Amber Rubarth’s “Tundra” are reasonably clear.
- Directionally the track is consistent and stage shape is nicely rounded.
- Perception of the presentation of stage is quite interesting. The percussion is perhaps just inside the perceived periphery of my head – but the violin is a little more distant, and has a perception of width and space. So these can be reasonably expansive for an IEM, but as with most IEMs the overall staging is ultimately more intimate than wide and deep.
- Reasonably spherically presented sound-stage.
- The applause section of “Dante’s Prayer” and Lakme’s “Flower Duet” was very well represented with a generally good feel of flow around me. Its also a slightly better shape than the original GT3 with a clear sense of depth.
- “Let it Rain” (Amanda Marshall) had its usual 3D-like sense of spatial presentation (it is the way the track was miked), but the presentation is definitely different. This is a track which is pretty hotly recorded resulting in reasonable amounts of sibilance (its actually in the recording). With the GT3 Superbass it hardly shows up. Good for this track – but shows how much that lower treble has been shelved.
Strengths (reference filter)
- Mid-range (one word – beautiful)
- Staging – nice sense of shape and space
- Very good impact and bass clarity for those who like a bit more thump with their music
- Non fatiguing, mellow and smooth
- There is definite slight bass bleed depending on the track
- Shelved treble does not help overall definition and resolution.
- Cymbals and other prominent lower treble instruments can be subdued.
The GT3 Superbass is an interesting IEM because of the impedance change from the original GT3
(84 vs 32 ohms) vs the slightly higher sensitivity (95 vs 92 dB +/-3dB at 1 kHz). Peter recommended a little extra amplification, but said that that the GT3 Superbass should still sound reasonable out of a smart-phone. The easy way to test this was to use my iPhone and then with the same track (volume matched of course) compare to the X7ii, and also to the iPhone + XRK-NHB.
This is a hard one to judge, because it is a very subjective and sighted test, but give the obvious bias a sighted test introduces, my preference when going back and forth with the 3 would be for the iPhone + XRK-NHB. It could be the really nice tonality of the amp, but it did seem to produce an ever so slightly cleaner and more defined bass. Switching to the Q1ii and Q5 also appeared to subjectively net small increases in audible dynamics (cleaner transients), so I am thinking that Advanced Sound’s advice that the GT3 Superbass scales with better amplification may have some merit.
You can definitely still drive them straight out of an iPhone (around 45% volume gave me a good listening level), but a decent power output (stronger DAP or amp) may ultimately net audible improvements.
RESPONSE TO EQ?
I need to reiterate that there is no perfect solution here. I use EQ to adjust to my own liking – and there is no universal correct EQ setting – it is purely individual preference. I wanted to address two things with the EQ – cut the bass slightly, and raise the lower treble to egta little clearer definition. For this I switched to the black filter – because it has a simply stunning mid-range cohesion.
You can see from the graph how I used the tone controls on the FiiO E17K and ultimately the -4 bass and +4 treble got things closer to my ideal signature, and the GT3 Superbass responded wonderfully – especially with my test-track (Pearl Jam – brilliant). A greater sense of overall balance, and a rise in clarity. A true targeted EQ would be better IMO. The GT3 Superbass transforms for me with carefully applied EQ – I just wish I could do this via the filters …….
COMPARISON WITH OTHER IEMS
A hard one to try and compare because of the filters. So for this one I looked simply to show the overall performance compared to the original GT3 and some other tunable IEMs (FLC8S, LZ’s A4 and A5). The other main comparison was with my reference IEM – the Alclair Curve. As a last minute addition I also added Brainwavz B400 as it is also a mellow sounding IEM in a similar price range. These comparisons were all done with the GT3 with silver filter, X7ii, (no EQ) – and volume matched using a calibrated SPL meter and fixed 1kHz test tone first.
So how do I see the overall value of the GT-3 Superbass? This is a tough one because like the original GT3, it does have a lot of potential and a simple change (more variety with the filters) can add a lot of perceived value. On the positive side the Superbass has great build and a comfortable fit, and the versatility has the potential to be good with the filter options (especially if you have Trinity filters). For its target audience (smooth and bass enhanced) it also has a very good sound signature. On the negative – for me, the current filter options simply don’t have enough variety. Is it worth $199? Well I’d say its good value at $199, and better than the original GT3 (given this is for a target market – and does achieve that target signature).
ADVANCED SOUND GT3 SUPERBASS – SUMMARY
The GT3 Superbass (like the GT3 original) is somewhat of a paradox as far as tunable IEMs go. It is once again extremely well built (as good as I have seen at this price point), with a good overall design, solid choice of materials and the tuning system is very easy to use (although somewhat limited currently). The cables are true quality, and the mobile cable having volume controls for both Android and iOS makes it extremely versatile. Comfort is good overall, and I have no issues with long term use.
As far as the SQ of the GT3 Superbass goes, ADV Sound have delivered what they promised. The Superbass is a warm, bass enhanced monitor with some real impact to the lower registers and an overall warm and smooth tuning. It doesn’t really suit my personal overall preferences, but I can absolutely appreciate their target frequency response, and the one thing I really love is the tuning of the mid-range. The filters are somewhat limited in their overall range, but the Superbass does respond well to EQ. For those looking for a smooth, bassy monitor, the GT3 Superbass does deliver, and I can recommend it.
For the price of $199 you are getting an IEM with a really nice feature set for the intended audience (those looking for warmth and bass impact). There is also the possibility for added value either through Trinity filters or modding and damping the existing ones.
I just want to close with thanking Peter for arranging the review sample.
|Adv-Sound GT3 Superbass||My Score||Out of||Weighting||Weighted Score|
|Bass quality||9.0||10.0||8 %||0.72|
|Mid-range quality||10.0||10.0||8 %||0.80|
|Treble quality||6.0||10.0||8 %||0.48|
|Overall tonality||8.0||10.0||8 %||0.64|