Ok, I have a subwoofer that is making mechanical noise (voice coil scraping the PM, it is out of alignment) and is making an awful and ear-piercingly loud HUM when it does not have a source input. I moved it around the house, and it still hums very loudly. If you short the input, the noise goes away. It's a shitty 10", i've been wanting to upgrade for quite some time, so now is the chance. A few things before I purchase one, however. I love HT & Car Audio, and am decently experienced with audio, but normally in two channels, but I still am a newbie, especially w/ the likes of 5.1/7.1 and upper spectrum components. I know the basics, signal paths, power, etc. first off, Is there a difference in the .1 or LFE (Low Freq. Effect) channel and the standard SUBWOOFER OUT? Does the LFE channel exhibit less or more acoustical information than the SUB OUT? I have a few ideas on what I want to do regarding subs.. I want either 15" or 18" But would really LOVE some 24" Hartleys.. sigh... dream on! 1) Build own box with a few Adire Audio Tumults or similar and add a nice amplifier 2) Single, large, powered subwoofer 3) two powered subs, each rear corner of the room (more even sound dispersion) If I build my own subs, I have yet to decide if I will use an amp like a Crown Audio rackmount, or a plate amp. But that is another story. Now on to the surround questions, short and simple Regarding 7.1, if the rear channels are the same towers as the front (for true seamless surround) what about the side/rear channel? Towers as well? Or... dipole? The only one I don't understand. Hell, they even make dipole subs now! What are dipoles, and what do they do? /Schwarzenegger Voice Lastly, does the idea of using identical front and rear speakers (towers) for seamless Surround sound seem logical? Or overkill? Thank you, and for those who commented in my last thread, thanks for the information!