Jeff said: Those who want to perfectly blend a powered subwoofer(s) with topflight main speakers in a high-end stereo system should consider as mandatory JL Audio’s CR-1 Active Subwoofer Crossover. It’s flexible, transparent, and intuitive to use. So grab an audio buddy, spend a few hours with a CR-1 to dial in your system to the nth degree, and you’ll surely be rewarded.
Read the SoundStage! Ultra review.
The gist: The external subwoofer crossover to buy.