I have very small ear canals (XS Spinfit tips are actually slightly too big), as well as small conchas. Something most people don't think about is how big the main body of the IEM is. An IEM can have a tiny nozzle, but if the main body is too big to fit properly it won't matter. A couple IEMs I can recommend for small ears are the Meze Alba (above budget by quite a bit), Akoustyx R-120 (also above budget, and needs a huge bass boost), and the Sennheiser IE 200 (goes on sale for $99 sometimes, usually on sale for $120).
I have tried all 3, and currently own the IE 200. I have the Akoustyx on the way, and it's supposed to arrive tomorrow.
Impressions of the IEMs I mentioned:
- Sennheiser IE 200: The least expensive, but the cable can be slightly annoying (and is hard to replace due to semi-proprietary connectors), there's a port in the nozzle that is part of a gimmicky tuning system (many people tape it up), and I personally had an issue with the nozzle angle (but you might not, fit is very individual). I'd recommend learning to use EQ with these, although they still sound decent without it. The nozzles are about 5mm wide with a 5.5mm lip, and are pretty short. The IEMs don't isolate as much as most others.
- Akoustyx R-120: I'd only recommend these with EQ, as they need a large bass boost to get to what I'd consider neutral (about 12-13db of boost, so if you listen really loud you might run into distortion). That said, they are some of the smallest IEMs I've found and have a very skinny nozzle (same as Shure/Etymotic/Westone, around 3mm). Also, the other options with this form factor and nozzle size (Shure and Westone) have other, worse problems (both Shure and Westone have very little treble, the affordable Shure SE215 has treble peaks as well, and everything from Westone is insanely expensive). The nozzle is on the longer side, but the small diameter means it works better with small tips than most. An adapter will be needed to use most aftermarket tips with these (many aftermarket tips actually come with the mentioned adapter, most notably Spinfit and Final). They isolate very well, since they are intended for live musicians.
- Meze Alba: I only tried these briefly, but they're the most neutral out of the box compared to the other 2. I don't know the nozzle size, but I think it's about the same or just slightly bigger than the Sennheiser IE 200. The shells are larger than the other 2 i mentioned, but still much smaller than most IEMs.
Given the relative lack of options for small IEMs, I think your best bet is to focus on fit first and EQ to preference. There are plenty of options for EQ on PC and Mac and a couple good tools on Android as well, but if you have an iPhone you will have to buy an external device to EQ. That could be expensive, since the most recommended option (Qudelix 5k) is around $100 (there are other options, but they either have severe limitations or are even more expensive).
Some advice on tips: I have tried many different tips, and depending on your ear canal size some good ones to try are Spinfit CP100+ (SS is 10mm, available through many retailers including Amazon and various hi-fi stores), ADV. Eartune Fidelity U (very expensive, but XS is an 8mm x 10mm elliptical tip, available through Amazon and the ADV. website), Moondrop Spring Tips (S is 9.4mm, available through Audio 46 and some other hi-fi stores but not Amazon), and Avantree XS tips (8.5mm, extremely small, I got these through Amazon). There's also NF Audio MS42 tips (XS is 9.3mm), but those have to ship from China because they're not carried by any local retailers (I got mine through Shenzhen Audio, which is one of the best known chinese audio stores). If you go looking on Amazon, don't believe most of the sizing information offered by the generic brands. I've seen tips advertised as being several mm smaller than they really were (a huge size difference when you're going to put them in your ears). The name brand tips I've tried have always been accurate in their claims.
