Not only for me, but in general I see a tendency to relatively small compact boxes (up to 12 L. net), as small living rooms or small purse are not useful for putting up 30-40 liters standing speakers. The case of compact boxes usually lack sound pressure in the bass range, however, interfere with the enjoyment of music. Remedy - one is always newly surprised - already a 25 cm woofer with 4 Ohm, who works in a self-built, stable 15-20 liter enclosure. And it is this active module of Gelhard with "only" 80 watts RMS sufficient. Of this I have already bought 4, happy friends and relatives. Ideal is in contrast to the passive subwoofer that the pressure can be adjusted individually, and I can leave it at 50% the volume control mostly. As a crossover frequency to 120 Hz have proven. I would like to mention that I preferred classical and country music hear that I can enjoy thanks to the subwoofer to the active module 150 GTV also about my 8 L. compact speakers. A timpani sounds again after timpani, organ by organ. The price / performance ratio of Gelhard module is unrivaled. Even if the amplifier / receiver no spec. Should have subwoofer output, so the enjoyment about the high level is maintained in / outputs. Conclusion: the purchase of this module does not repent. Jürgen Simon, 73 years, 97999 Igersheim
