Comparing the Motion 40s vs. Motion 60s, if you have a really good (fast & clean) subwoofer to go along with your system, try the 40s too. Remember, AMTs are super-duper-fast. Need a good fast sub to keep up.
With the smaller mid-woofers and smaller AMTs in the Motion 40s, they sound a bit more neutral and a tad less tubby on the bass using a mid-fi grade amplifier. If you step up like @knighttodd has running a higher current/quality amplifier to control the woofers, either ML40s or ML60s "can" sound even better. The room size/shape and speaker positioning matters too of course. Your situation may vary.
The Motion 40s are (92db sensitivity) and Motion 60s (94db sensitivity) and I did some testing with a small 10-watt triode tube amp for fun. While they sounded nice and smooth, good midrange, these Motion series speakers do appreciate a bit more power and control using a more capable amplifier (think big transformers in the amp) to perform their best.
Running standalone speakers only, I liked the Motion 60s only when paired with really good amplifier(s). Need not buy the Motion 60s (for 2ch audio) if you re only going to run a lower grade HT receiver, its a waste of money for the 60s. They deserve a lot more. With a great main stereo amplifier, and paired with a great subwoofer the midrange and mid-bass on the (lower model) Motion 40s also sounded really nice, neutral, nothing stood out too much. A few buddies preferred the Motion 40s in a smaller room setting too.
I did not get a chance to hear or try the Motion 60 speakers with a pair of really good 100wpc push-pull tube amplifiers. Tried the 40s with them though, and they sound great. I design and build my own AMT speakers for fun the past 3+ decades, and believe there is even more potential to the ML Motion 60s given a chance. Step up on the front-end, power amplifier(s), and the Motion 40 or 60s can sound very nice. Best of luck
@oldaudiophile btw, I worked at ESS early 1980s :)
With the smaller mid-woofers and smaller AMTs in the Motion 40s, they sound a bit more neutral and a tad less tubby on the bass using a mid-fi grade amplifier. If you step up like @knighttodd has running a higher current/quality amplifier to control the woofers, either ML40s or ML60s "can" sound even better. The room size/shape and speaker positioning matters too of course. Your situation may vary.
The Motion 40s are (92db sensitivity) and Motion 60s (94db sensitivity) and I did some testing with a small 10-watt triode tube amp for fun. While they sounded nice and smooth, good midrange, these Motion series speakers do appreciate a bit more power and control using a more capable amplifier (think big transformers in the amp) to perform their best.
Running standalone speakers only, I liked the Motion 60s only when paired with really good amplifier(s). Need not buy the Motion 60s (for 2ch audio) if you re only going to run a lower grade HT receiver, its a waste of money for the 60s. They deserve a lot more. With a great main stereo amplifier, and paired with a great subwoofer the midrange and mid-bass on the (lower model) Motion 40s also sounded really nice, neutral, nothing stood out too much. A few buddies preferred the Motion 40s in a smaller room setting too.
I did not get a chance to hear or try the Motion 60 speakers with a pair of really good 100wpc push-pull tube amplifiers. Tried the 40s with them though, and they sound great. I design and build my own AMT speakers for fun the past 3+ decades, and believe there is even more potential to the ML Motion 60s given a chance. Step up on the front-end, power amplifier(s), and the Motion 40 or 60s can sound very nice. Best of luck
@oldaudiophile btw, I worked at ESS early 1980s :)