Review on Beyerdynamic DT 990 PRO Open Studio Headphones - High-Quality Sound for Professionals by Micha Kowalski Czajo ᠌

If you take them for a spin without first letting them warm up, you may permanently damage the headphones' internal structure. Classical music suffers from a high frequency boost and a slight dip in the middle, making instruments like the cello sound uninspired. Acoustic and classical guitar, however, sound great without additional amplification. The headphones have a small wire inside, thus you may need to warm them up before using them. While this song isn't particularly enjoyable, the tube preamp can enhance the listening experience by making instruments in the foreground -- which could otherwise go overlooked on other headphones -- more prominent. In headphones, especially with a subpar amplifier, the sound can seem thin and distant. Don't bother trying to explain the difference between this and the HD 650; they won't get it. Consider the model objectively; you will inevitably add the headphones to your collection; however, you should not use the headphones with your mobile device or portable player.