I have tiny ear canals. The IEMs I have right now are KZ models with bare nozzle/flange outer diameters between 5.58mm and 5.7mm (as measured with my cheap digital calipers). They insert with no pain while bare, but gave no isolation. With my thinnest smallest AE memory foam installed and fully compressed, I cannot insert them at all. The diameter of that setup was between 7.2mm and 7.57mm using the compressed small size AE foam. Silicone doesn't work for me at all. After rummaging around the house for solid cylindrical items of different sizes, I found my left ear canal diameter is about 5.78mm and the right is about 5.84mm, at least those were the largest size of the measured items that I could comfortably (and safely) insert. I marked 7mm for the length I would insert, so as not to come anywhere close to my eardrum. So my left ear canal is only about 0.7mm larger in diameter than one of the KZ bare nozzles.
Anyway, the only way I could insert them with anything to cushion them was to strip the memory foam off the rubber core of the AE foams. I ended up with just a tiny bit of foam residue over the rubber. It still felt like a cheese grater going in with the rubber core installed, but for the first time, I was able to actually insert an IEM and get some grip and isolation. That diameter was about 6mm and larger than my ear canals, so it adds a lot of pressure and I don't think I could wear it very long. Up to now, the few times I had tried to use these IEMs, they would repeatedly slip out of my ear. I probably never had them inserted beyond the overhang of foam at the end of the nozzle.
Since I also have a problem with earbuds staying in my ears, my question to you folks is:
Do you know of any highly regarded inexpensive Chi-Fi IEMs that use a narrow nozzle (I think 3.0mm or 3.5mm) that would use the T100 tips? That would mean the hard core of the nozzle would be 2mm - 2.5mm smaller than what I have. I'm hoping that starting with a much more slender nozzle will allow a memory foam tipped IEM to fit me better. My preference leans toward warm bass heavy, genres 70s - 90s, R&B, pop, rock, disco, jazz and some classical. I'm getting desperate for a solution. Thanks.
Edit: My budget would be under $15, hopefully.