Amp for Martin Logan Motion 60XT


I seemed to be digging into a dark hole about recommended speaker wattage. I’m not sure how much amplification I should strive for to power the Motion 60XT’s. ML recommends 40-400watts for these. Is that in 4ohms? If I got an amp that could do 700watts in 4ohms would I damage the speakers? I am interested in either Hypex or Purifi amp. Not sure between NC400, NC500, NC1200, or Purifi. Any recommendations?
Thanks,
Chobes
chobes11

Showing 4 responses by georgehifi


Yes, that’s why you need to study "independent tests" closer like Stereophile’s into 2ohm loading, and if they don’t have it you know why, they can’t handle it, complain or blow fuses.
Class-D’s do well doubling wattage from 8ohm to 4ohm. But they **** themselves trying to double wattage from 4ohm to 2ohms, sometimes even going backwards
Good BJT linear amps will do this, like the ones I posted about.
That why I posted this to you https://forum.audiogon.com/posts/1942037
If it were correct that all you need is big wattage we’d all own $429 Behringer 3000w amps
I’m not saying Class-D won’t work and sound ok into your speakers, it probably will and sound ok to you, till you hear a linear amp some day that can do 2ohms it without breaking a sweat, then you’ll understand.
Cheers George
chobes11 OP
I’ve been doing a lot of research on the Hypex class D and they are supposed to be phenomenal.

You need to understand how they behave into 2ohms, when you do they become far from phenomenal.

Cheers George
chobes11
Amp for Martin Logan Motion 60XT

They are 90db, so they don't!! need a lot of wattage, a 100-150watts at into 8ohm will do.
But they do have an amp taxing (for current) 2ohm dip around 200hz-400hz in the upper bass, they also have a taxing -phase angle of 65' at 70hz and also 3ohms from 70hz-150hz in the low bass.
http://www.prespeaker.com/images/201702/Motion-60XT-impedance-thumb-600xauto-13547.jpg

These speakers need an amp that can do current at 2-4ohms without breaking a sweat right through the bass, "if you want get the best out of them." don't just buy an amp for it's big watts.   
No Class-D's for these if you want the very best from them.

Integrated
Gryphon Diablo 120 or the 300 will both do nicely
Parasound  Halo Integrated Hint 6
Eariler Parasound Halo Hint

Poweramps
Parasound A21+
Earlier Parsound A21
Earlier Krells  etc etc.

Cheers George



chobes11
Stay away from Class-D into 2ohms with these speakers

Don’t listen to the watt junkies, you can’t make up current ability with watts, to drive hard to drive speakers with, if you could we’d all own these $429 Behringer 3000watt Class-D’s
https://www.google.com/search?q=behringer+3000+watt+power+amp&source=lnms&tbm=shop&sa=X&ved=2ahUKEwjpyZ74oLXpAhXkyzgGHcm7CQoQ_AUoAXoECA0QAw&biw=1202&bih=821#spd=11529695133366263086

The 25watt!!!!! Mark Levinson ML2 monoblocks would eat those 3000w Behringers alive to a given volume level on your ML Motion 60XT’s
https://img.usaudiomart.com/uploads/large/2229206-5c605986-mark-levinson-ml2.jpg

Cheers George