The 3.7 is a 3-way design, like the 3.6, but, it is a full-range ribbon design. We are calling it "trickle-up" technology. The concepts that worked so well in the 1.7 were incorporated in the 3.7.The 3.7 was subjected to "blind testing" by a panel of audiophiles and casual listeners. In addition to better sound, there is one more important improvement that you can test for yourself. If you have the opportunity to hear the 3.7s at your local dealer, try this experiment---Ask the dealer to place the speakers with the tweeters on the outside. Note how the imaging remains remarkably stable when seated far off-axis. With some speakers it is necessary to sit in the "sweet spot" for good imaging. If you are too far out of the sweet spot, you will hear predominately one speaker. With the tweeters on the outside, the 3.7 has the widest sweet spot of any of any previous Maggies. If you prefer to sit only in the "sweet spot", try the tweeters on the inside. Be sure the speakers are toed-in. In all cases, the tweeter should not be closer to the listener than the bass section.