The Advanced Sound Group was a new company to me, so I really didn’t know what to expect when Peter Yoon contacted me. He told me they had a new IEM in the pipeline, and I always like to hear new products from new companies, so I jumped at the chance. Within a few days I had the GT3 in my hands (and in my ears), and the last week has involved putting its through its paces. What I didn’t realise when I said yes, was that it is tunable! So lets take an in-depth look at the GT3 and discover a little more about Adv-Sound and what they are about.
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 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 them 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 straight from the headphone-out socket of many of my portables, but predominantly the FiiO X7ii, X5iii, and my iPhone. I have tested them both amped (Q1ii and Q5, XRK-NHB, and E17K), and straight out of the DAPs listed.
In the time I have spent with the GT3, 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 arrived in a 128 x 185 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. They’ve put a fair bit of thought into this, and while the front is simple and elegant, the rear is a plethora of information. The techno “objectivist” in me loves this!
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 GT3 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||Proprietary damped 10mm dynamic driver|
|Freq Range||10Hz – 40kHz|
|Impedance||32Ω +/- 15%|
|Sensitivity||92 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||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 black filter. Later in the review I’ll discuss the other tuning options. Channel matching is very good.
The GT3 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 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 measures ~12mm in width, and ~24mm in length (including the nozzle).
The outer face of each IEM has the model number (GT3) engraved, and the inner face has the company (ADV). At the top and to the rear of the GT3 is the MMCX housing which has a small L or R embossed on the black housing. 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 a 3 year warranty. These are seriously beautifully built IEMs
Internally the GT3 uses a single 10mm dynamic driver. The material for the diaphragm is simply PET, but Peter tells me that the “secret sauce” to the GT3’s sound is from the combination of the extremely light weight voice coil and proprietary damping on both sides. When combined with the stainless steel acoustic chamber, this aids in the extension of the sub-bass, and also in the lower treble.
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 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 depended on the filters – but was either Sony Isolation 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, 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 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 2-7 kHz, and the main changes were between 3-4 kHz and max change under 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. Likewise if I use the silver and black, the same thing happens. Its only when I try red and black that my brain is simply unable to adjust. What this tells me is that Advanced Sound has probably missed an opportunity here to have 3 distinct and different sounds via the filters supplied. 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 new 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 quite V shaped sound with varying levels of upper mid-range. The V shape does create distance with vocals, and especially male vocals lose some weight, and can be dominated by upper mid-range emphasis (creating a little haze or grain). They are still quite detailed and articulate though. The main problem for me (and I know this is purely personal preference) is that there really isn’t a reference setting, and these earphones are great in every other way (build quality, extension, clarity etc). I’ll discuss EQ later – but first somewhat of an epiphany.
I thought 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 even bigger V shaped tunings, so I suspected most of their filters might not work (and some of their lighter bass tunings were too extreme). But the red was an improvement (IMO), lowering the upper mids, giving a bit more mid-bass, and taming some of the peaks. When combined with the Shure Olives (different diameter) I got a perfect fit, and great isolation, and it would be my preferred sonic signature over the other filters. We’ll continue the review with the GT3 black filters (my preference of the GT3 default options), 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 Sony Isolation tips. I used the X7ii simply because paired they gave me both a very transparent window to the music with low impedance, and also more than enough power. I used the black filter – because listening without EQ, this is the most palatable (and balanced) filter for me.
For the record – on most tracks, the volume level on the X7ii (paired with AM3a) was ~55-60/120 Single Ended (on low gain) which was giving me an average SPL around 65-75 dB. 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 – good extension and is elevated. Has some rumble even at my lower listening levels, but it is not massively excessive. With sub-bass dominant tracks (like Lorde’s Royals) there is no noticeable bleeding (or masking) into the lower mid-range.
- Mid-bass – reasonable impact, but takes a back seat to the sub-bass. If anything I’d probably prefer a little more mid-bass thump, but overall this tuning works. Overall the bass is not what I’d call visceral – but there should be enough to satisfy most people.
- Lower mid-range – there is a recession compared to sub and mid-bass, and also the upper mid-range, and does sound slightly distant. Male vocals do not quite have the same presence as female vocals, but they do have enough body to be enjoyable for the most part. I did find some of my classic rock artists (10CC and even the Eagles) struggling a little from what I’m used to.
- Upper mid-range – elevated compared to lower mid-range, and there is a rise (15-20 dB depending on filter) from 1 kHz to a first peak at 3.5 kHz. The result is a clean and clear vocal range, with very good cohesion and some euphony for female vocals to sound sweet and elevated. There is also good sense of bite with guitars – and plenty of presence for fundamental cymbal strikes. Because of the recession with the lower mid-range and the extent of the upper mid-range peak, it can tend to make some male rock vocals appear thin and accentuate harmonics to introduce haziness. Its not terrible – I just think this is an area which is over-done.
- Lower treble has very good extension, and is quite sustained through to 10kHz with peaks around 6-8kHz. This isn’t emphasised compared to the upper mid-range, but my recommendation would be to drop both by at least 5 dB to introduce more balance. The current set-up presents a lot of clarity and detail, but there is a lot of glare or grain.
- 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 good, and there is an effortless expression of detail, particularly in the upper mid-range. With Nil’s Lofgren’s “Keith Don’t Go” (acoustic guitar), I could easily pick out micro details (movements on the fret-board etc).
- Cymbals hits (especially hi-hats and crash-cymbals) have nice presence with this filter, and there is good sense of trailing decay. No signs of bass masking this detail. My only critique would be that glare or grain – a sure sign that this area is just a little overemphasised. Cymbals can be a little “tizzy”.
- Portico Quartet’s “Ruins” is a good track for checking the balance on drumstick clicks, hi-hat taps and general cymbal decay, and it is clear that the GT3 picks up this detail really well. Again my only issue is that cymbal brushes become blobs, and (especially with the silver and red filters) the upper mid-range becomes shrill and peaky.
- Directional queues are very good and also very clear.
- You get clear direction of sound, and it is very consistent.
- Perception of the presentation of stage is just outside the periphery of my head – so these are 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 – with a slight L/R dominance (so slightly more width than depth).
- 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.
- “Let it Rain” (Amanda Marshall) had its usual 3D-like sense of spatial presentation (it is the way the track was miked). There was sibilance with Amanda’s vocals – and I know its present in the recording – so not unexpected. The sibilance was moderately strong and reflected the heightened upper mid-range and lower treble emphasis.
Strengths (black filter)
- General clarity
- Imaging and intimate staging (with slight L/R dominance)
- Good at lower listening levels
- Good (IMO with electronic and EDM genres – particularly those with female vocalists)
- Upper mid-range and lower treble are over-emphasised, and this causes grain or glare with many recordings.
- Male vocals (particularly with classic rock) can be a little lean
The GT3 is an interesting IEM because while it is relatively low impedance (32 ohm), it is also low sensitivity (92 dB +/-3dB at 1 kHz). This tends to promote the thought that the GT3 would need (or at least benefit) from additional amplification.
In real world tests, needs close to 50% volume to hit my usual 65-75dB listening level. Introducing the XRK-NHB (after volume matching) did give a (for me) a more pleasing tonality, but I’m not sure if this is simply just the amp (its definitely one of the best sounding portable amps I own). 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 will scale with better amplification have some merit.
You can definitely still drive them straight out of an iPhone (and to reasonable volume), but these are a little like the MEE P1 – a decent power output (stronger DAP or amp) may ultimately net audible improvements.
RESPONSE TO EQ?
For this I wanted to see how the GT3 would react to a flattening of the entire frequency spectrum. The easiest way to do this was using the E17K’s tone controls, and dropping bass back by -2/-4 and the treble back by -6. I’ve included a graph so you can see the effect of this. I then went back and tested some Pearl Jam, 10CC and Eagle – and the improvement for my preferences was immediate.
A greater sense of overall balance, and no real drop in clarity. A true targeted EQ would probably be even better. The GT3 transforms 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 some other tunable IEMs (FLC8S, LZ’s A4 and A5). I also quickly compared to a couple of well regarded IEMs in the $200 range. These comparisons were all done with the GT3 with black filter, X7ii, (no EQ) – and volume matched using a calibrated SPL meter and fixed 1kHz test tone first.
GT3 vs Other Tunable IEMs
GT3 vs Other Non-Tunable IEMs
So how do I see the overall value of the GT-3? This is a tough one because the GT3 does have a lot of potential and simple retuning and reissue of the filters could effectively transform it into a high value IEM. On the plus side – it has great build and comfortable fit, and the versatility has the potential to be good with the filter options (especially if you have Trinity filters). 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, but not stellar value (yet). I do genuinely see a lot of potential in the GT3.
ADVANCED SOUND GT3 – SUMMARY
The GT3 (like the LZ-A5) is somewhat of a paradox as far as tunable IEMs go. It is extremely well built (as good as I have seen at this price point), with 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 goes, if you’re a fan of a V shaped sound, and especially a more recessed lower mid-range with more emphasised upper mid-range and lower treble (perhaps similar to some of Trinity Audio’s mid-centric monitors), then you may very well like the combo. For me it is too coloured, and the fact that the filter combinations only affect a small frequency range unfortunately don’t give a lot of overall options.
If I apply some simple EQ though (and get them a little more balanced in frequency), they become a truly engaging IEM, and the trick shown earlier with the E17K’s tone controls really does transform them into a good monitor.
For the price of $199 you are getting an IEM with a lot of potential, but much of it is unrealised. If you are prepared to EQ, or perhaps DIY some filter tuning through added damping – these could be really good. In their current form though I don’t necessarily see them as an upgrade sonically from the likes of the LZ-A4 – except in the comfort stakes.
I just want to close with thanking Peter for arranging the review sample.
|Adv-Sound GT3||My Score||Out of||Weighting||Weighted Score|
|Bass quality||7.0||10.0||8 %||0.56|
|Mid-range quality||6.0||10.0||8 %||0.48|
|Treble quality||6.0||10.0||8 %||0.48|
|Overall tonality||6.0||10.0||8 %||0.48|