First let me say, I have done countless hours of research when upgrading my old pieced together surround sound. My left and rights were punchy enough that I did not need a subwoofer, as they had an 8" sub included. So my theory was to go more slim and sleek, but still wanted a little bass because I was not buying everything all at once. So, after reading many reviews, blogs, and forums, I decided to go with the motion 4, due to the baffled-port design and their dimensions. Also, the guys at Best Buy let me crank them up in the store. And let me tell you, these DELIVER! I hooked them up with my old Aiwa 180 degree speakers and set them as zone 2 on my receiver and had my Aiwa's on zone 1. So I could listen to all types of music, movies, and cable tv at the same time. These speakers produce a very accurate sound with a substantial bass element for their size. Yes, the folded tweeter can get a bit bright, but with tweaking of the receiver and sound settings, was able to balance it out beautifully. They do open up and sound better the louder they get, and let me say without any distortion. But after the break in period, they are starting to sound better at low volumes than out of the box. I agree with most in saying they are better for music than movies, but only slightly. You really have to be an expert audiophile to hear the difference, which I consider myself. After, many dvd's, cd's, Bluetooth, and airplay these could not even compare to my older speakers, which consisted of one 8", 3 mids, and 2 tweeters. That's saying a lot coming from a 4" mid and tweeter. But it is true, and having my wife listen to both, she even made the conclusion same as me.
I have since compared to sound bars and other speakers and keep bringing everything back and sticking with the Martin Logans. So, now I have paired them with a Motion 8 center channel and yes...broken down and bought the 700w dynamo sub. The center channel is connected and the sub is a Christmas present to myself from my wife, which she doesn't know about yet...wish me luck. But I can't express the quality of sound you will get from the speakers. It really doesn't compare with anything else at this price range. I am using a Sony STR-DN850 and it pushes them just fine and keep getting better the longer I listen to them.
If you are looking for a superb quality sound and need to save a little space, these speakers are highly recommended! The Motion series will be my surround sound for many years to come and I just plan to update my receiver as needed. Thanks Martin Logan on being dedicated to producing accurate and superb sound in an "relatively" affordable and space-saving package!