actually, it is pointless, but after so many reviews yet a dranzuhängen.Ich would like to clarify something. Of course, the box may reach neither the SPL nor the deep bass of a 10-inch monitor, which is not simply physical. But to bring control to such a large diaphragm to generate sounds, it needs a) damn good materials and b) a damn good amplifier is to up some more cash in hand to take this as a subwoofer costs. Otherwise haste this headache-headbanger-boom-boom sound as of many youthful cars herausdröhnt.Wer wants needs a size box with appropriate wattage. This is also the same position taken to dispute individual components to active subwoofer of these smaller type. Conclusion: If you only want to listen to music and a well-balanced with respect to the other frequencies Bass, beside it might even want to entertain, is well served very well with this device. The setting / adjustment possibilities are absolutely sufficient to achieve a balanced sound at halfway normal driving noises occurring - and at really reasonable costs. The design of the subwoofer is impeccable and durable, the installation for everyone who has ever connect a car stereo, without any problems. I admit definitely full stars for this Kastl !!!