Driver: Three Balanced Armature
Configuration: Three ways - one low, one mid, one high.
Dual Bore Design
Shell colour: “Black Mamba”
Face Plate: Burl
Driver: Four Balanced Armature
Configuration: Three ways - dual low, one mid, one high.
Dual Bore Design
Shell colour: “Black Mamba”
Face Plate: Burl
4,Ai (left) and 3.Ai (right)
Packaging, Accessories and Build Quality
Though what I have received is package for the loaner tour, the package does look pretty much like what you would expect from a custom IEM. You will get an otterbox-like hard case, earwax cleaner, rubber band, detachable cable, the earpieces and good quality single and double flanges eartips of various sizes.
The stock cable is similar to Westone cable, which is decent and durable though nothing particularly fancy. The eartips are quite excellent in quality. The earpieces themselves are well built and actually quite small in size. The wooden faceplate is gorgeous. The nozzle of the earpiece that holds the eartips in place is what I’ll call ‘pig nose’ - as it seems to be just like a custom IEM’s nozzle that has been flatten out by hand, instead of molded to have ridge and socket like an universal IEM’s nozzle. It isn’t too big of a deal as it still holds the eartips in place fairly firmly and they never come off by their own.
Overall the build quality is excellent for something that is essentially hand built. Yes, they are not as precise as machined parts - but given their semi-custom nature, I think they are well acceptable.
Size comparison (from left)L 4.Ai, Lear LCM-5, and 3.Ai
Given these IEM are loaner, I didn’t carry out my usual 50 hours burn-in. But that shouldn’t be too much of an issue since balanced armature tends to benefit minimally from burn-in.
The sound signature of 3.Ai is warm, rich and laidback. Bass carries a good sense of fullness, if not a tab slow and fluid which resembles dynamic driver rather than BA. It reaches down fairly deep with good impact, and by not mean huge in quantity. But because of having a richer and weightier tone, bass hit tends to sound bigger than it actually is, and more fun no less. Mid is slightly blend on the lower end, neither sweet nor lacking detail. On the upper end however, there is an obvious dip and peak that makes it sounds a tiny bit off and grainy, like having a little itch on the back of the throat that you can’t get to. Treble extends well, but leaning toward the smoother side. It only misses the edge of sparkle and doesn’t actual sound dull, though analytical listener probably won’t find it enough. Soundstage is only fair, mostly because the warm and fullness of the presentation tend to get into the way of having a clean and clear separation and positioning. The biggest weakness of 3.Ai is however on the dip and peak in the upper mid. The dip reduces textural detail while peak gives it a rougher edge even though the IEM doesn’t sound sibilant. It makes the IEM sounding less easy and fun on the ears, which would have otherwise been a more enjoyable sound. Still, the three drivers IEM is competent enough to stay in the sub top-tier category.
The 4.Ai carries the same kind of warm and richness as the 3.Ai, but fuller and more forward. Bass runs decently deep and not as big or impactful as 3.Ai. It has the same rich and fullness in tone, but quantitatively closer to be just a notch more than neutral. Lower mid is much like the 3.Ai – decent, but nothing spectacular. The upper mid however behaves much better - fuller, though still not sweet, but definitely not grainy any more. Low treble is mostly smooth while higher treble has a bit of roll off, missing a fair amount of the top sparkles and crispiness. Soundstage is fair as well, for mostly the same reasons as 3.Ai. In a way, the 4.Ai is the mature version of 3.Ai. It is calmer and smoother on one hand, but not quite as fun on the other. It addresses the biggest weakness of the 3.Ai, which is the big dip and peak, but never quite brings it to the next level. The overall warm and neutral tone with the smooth treble actually makes the 4.Ai closer to a stage monitor sound, but it would have been better with a sweeter vocal and a touch more brightness. All and all, the 4.Ai is a notch better than 3.Ai.
Magnus 1 cable (left) and stock cable (right)
Magnus 1 Cable
The Magnus 1 cable is Heir Audio’s own upgrade over the standard, Westone’ish cable. As mentioned, the standard version is actually quite good on its own. The Magnus 1 however, is even better in build quality. Despite being quad braided, with a slightly larger pins connector and a Neutrik right-angle 3.5mm plug, the cable doesn’t feel bulky at all. The cable is still soft and flexible, and seems more durable overall. It makes for quite a good alternative to the stock cable if you even need to replace it. The price tag ($150 regular or $110 for Heir Audio CIEM user) also seems reasonable enough, especially compared to many other after-market cables out there. However, I don’t find it a must-have for either the 3.Ai or 4.Ai and you certainly are not missing any of the Heir experience with just the stock cable alone.
I remember that there was a huge stir in the community when the 3.Ai and the 4.Ai were announced. The idea of universal custom was almost instantly followed by many of the competitors and caught on like wild fire. The very notion that custom IEM, which are generally being believed to be better than universal IEM, can be made into universal for mass production (and thus result in lower pricing) is a very powerfully one. So do the 3.Ai and 4.Ai really outdo the universal? Well, yes - but not entirely. They are definitely better than entry- to mid-level IEM. But relative to their price point, I don’t think they have any particularly distinctive sonic advantage over the top-tier universal. Don’t get me wrong – despite having some issues, both 3.Ai and 4.Ai are still good sound IEM in their own right. It is just that being a universal custom doesn’t automatically make any IEM more special than a competent universal, at least not in sound quality.
A thank to Heir Audio for the loaned samples.