The pair I received seems defective because the sound is noticeable unbalanced. The center of stereo is always on the right side of my head, in other words the right IEM sounds much louder than the left one.
I'm new to IEMs but I made a lot of research, it promised a lot. Soundstage, microdetail etc are common terms but doesn't make a lot of sense in traditional earphones but you get the idea very quickly when listening to Tchaikovsky. If you're doubting in buying the BA5, don't. Just buy them. The construction is very nice, they have a nice heft and they feel good in your hand. The cable feels a little bit cheap but it seems that's the standard so mine will have an upgrade. Lows as others have put are a little bit behind, but just add 2 or 3 levels 2-4 kHz in the equalizer and that's it. Also I bought a TRN case from another store and Ali combined the items. Shipping to México was 3 weeks, which is fast compared to other purchases.