The ACE840TT, like its younger sibling the ACE640TT, offers excellent stereo sound and takes up half the space of a standard speaker pair, while still delivering smooth, 2-channel sound.Works great for whole house audio applications. These speakers were created specifically for an application where you have a right (+/-) and left (+/-) stereo signal coming into a room where you only have space for a single speaker. So you would connect one pair of conductors to one set of inputs (+/-) and the second pair of conductors to the second set of inputs.The ACE840TT produces more bass response and covers a larger range than the 6.5" version.