I've had the M50's and 440's for a while now. It was not until recently that I realized I could fit the 440 pads on the M50's. I think you'll find the results favorable. In my opinion the stock M50 pads are very cramped (perhaps I just have big ears...) and the 440 pads offered what felt like a relief from this. Sound quality wise, I felt these pads really "opened up" these cans. I'm still learning the lingo here so excuse my sucky descriptions of sound. I believe what I'm trying to say is that the 440 pads opened up the soundstage. Anyways, hope you all enjoy this.