Experimenting with bi-amping brought better results than ever. I am using an Eden Navigator preamp, a WT1000 power amp, a D215 XLT, and an Acme LowB-2. I used to use both cabinets full range. This sounded real good- I could tweak the tone and balance to dial it in. Then I tried biamp stereo mode. Wow! this really cuts. I think because the Acme has the lows rolled off, It works more effeciently. Also, I think there must have been some phase cancellation before ( The Acme is rear ported, and the Eden front ported). I can really dial in everything better-easier. Even the effects are better heard. It really benifits to have a balance, variable X-over, and tone controls on the power amp too. The D215 XLT really shines doing what it does best- (Pumping out lows that you can hear and feel).