My wife first used it on a karaoke system. The karaoke system already has small room reverb and echo built in. Microphone used was bluebird condenser and she was astonished by how good it sounded with a lot of volume and accurate sound. Although that's not what I've been hearing coming out of the speakers lol! I also used this on the Fender acoustasonic 15, (plugged concert guitar / MXR M300 Reverb) and (Blue Bird mic / TC Helicon Mic Mechanic 2) pedal I get excellent sound with a little tweaking. 4 stars being a workhorse studio phones, higher priced earphones are better if not best. But this is adequate for our needs.