HD 600

I have not heard the HDB 630, but I will say that price, or even the fact that it's wireless are not significant limitations. There are things cheaper Sennheiser models that do some things better than the HD 800 S, in my opinion. A good example is the midrange and treble of the HD 600 and HD 650, fo

Tubes do help the HD 800 S, it becomes more "HD 650-like" by adding some warmth and taking the edge off in the treble. Though it's a much "Softer" presentation than the HD 650 below 4kHz, as shown below. Though, the maintenance needed to upkeep tube amps can be annoying if you're used to solidstate.