I'm in need of a pair of closed headphones for a class that uses digital pianos. I have AD700s at home at the moment but due to their open nature they're not suitable for use in the classroom. Minimal to no sound leakage is a must. Beyond that, I'm looking for comfort first and foremost as these will be 2 hour sessions on average. Sound quality isn't as important but as always it's still appreciated; if nothing else I'll likely find a way to put whatever I get to use after I'm done with the class as well. $50 or less would be best but I might be able to stretch it a little bit if it's REALLY worth it. Thanks for reading.