Dtel, when bass is crossed over at a low enough point, you can't tell where it's coming from. If you didn't know I had subwoofer drivers next to my ceiling, you'd swear that the bass was coming from my mains. Before you settle on where to install your IB, you need to take a conventional sub and put it where you think you want your IB and listen to it. If you can blend it with your mains at that location, the IB will blend as well. It's an important step, because once you install your IB, they're not easily moved. Once it's installed, you'll never go back to a conventional sub. I had subs from Infinity, Klipsch and SVS before I built my IB. I have no desire to upgrade my anymore.