Ok, here's my situation. First off, I play 7 string bass, so I need a big frequency range. I have a Gallien-Krueger 400RB-III head, pushing an Avatar 2x10 cab and an SWR Workingman's 1x15 cab. It does an OK job of reproducing all the frequencies, except the lowest 4 or 5 notes. Below E, it breaks up a bit. By C#, C and B, it's farting. I am planning on getting a power amp and replacing the SWR with a Yamaha 1x18 PA sub (the kind JT uses). I have to signal chain options.... 1. Bass to head, speaker output on head to Avatar for 150 watts at 8 ohms. Line to power amp, putting 400-500 watts into the Yamaha at 8 ohms bridged. (Carvin DCM600) 2. Bass to head, line to power amp, side 1 to Avatar, side 2 to Yamaha, pushing about 400-500 watts a side at 8 ohms. (Carvin DCM1500) 3. Bass to head, line to power amp, bridged to both cabs, about 1000 watts at 4 ohms mono. (Carvin DCM1000) So far, I like option 2. It will cost more, and weigh more, and take up more room in my rack (assuming I get a Carvin) I _think_ I want to bi-amp, or at least try it for a while. How do I do this? What crossover do I need? Where do I put the crossover? What should I set the crossover at? (100hz is my idea) Sorry this is kind of scatterbrained. That's just how I work Thanks in advance.