For over a decade, I've been listening to my own practicing and recording sessions. I've covered the mics, recorders, and other gear in previous posts. In this post I would like to cover the output source, specifically the headphones.
My search for the perfect practice headphones started when I wanted to isolate what I was hearing from the mic with minimal noise from the cello. At first, I tried on-ear noise isolating headphones. Those were a joke; they just distorted the sound. Then someone recommended in-ear monitors, Shure SE215. I was blown away by the quality. This was not your average pair of earbuds. The volume and precision were amazing. Just what I needed. They come with a variety of foam and silicone tips for comfort and isolation needs. Most of all, nothing was sitting on top of my head.
In a live (miked) setting, in-ear monitors are ideal. You can set the level/panning of the mics to exactly what you need without cutting out a lot of the sound like musician's ear plugs do. I would highly recommend in-ear monitors over the on-ear headphones. My Shure pair served me for about 7 years, unlike average earbuds that break a lot quicker.
Shure SE215 has 1 driver. After I retired my Shure, I bought Westone UM20, with 2 drivers (bass and treble). The sound on those was a lot smoother than the SE215. UM20 has very good detail, not obscured by the boominess of the bass. I also own Westone UM50 (5 drivers). The 5 drivers work like a multiband EQ. To me, even though the sound is thicker and broader, the UM50 obscures the details, and doesn't make as good of practice monitors. UM50 is great for general listening.
All 3 of the above in-ear monitors are great. It just depends on what you are looking for in sound. If you have a harsh and bright mic, UM50 with smooth that out. If you have bassy or flat mics, SE215 and UM20 are perfect for that setup. Of course, if you are on a small budget or have never tried out in-ear monitors, get the SE215.