PD4 is specially tuned for singing and listening in Karaoke room. It delivers customers with an ultimate Karaoke experience. With DMX special designed high efficiency woofer, PD2 deliver u the wide dynamic range and high output capacity performance.The most important feature of PD2 sonic performance is that the depth and punch of the bass are combined very well. The full bass and smooth mid-frequency are beneficial to singer to catch the rththm easily, which will express the emotion of your heart through such a real vocal sound reinforcement.