[AdamG666]

I just received these today and im looking for some advice, the audio leaks a fair bit and the isolation isn't very good, will buying better pads improve this? I'm using a Turtle Beach DSS1 and the sound is good at medium volume but on some YouTube videos they distort really badly past half volume, is this just bad audio from the video or the DSS not been able to power the headphones properly?

 

[armink]

will buying better pads improve this?

Definitely, Cowhide ZMF Oval's are probably the best pads for the M40x's, and not only help with isolation but also improve sound and comfort.
The only downside here is that they're thick (very thick) and you would probably look like an idiot if you ever want to take them outside.

they distort really badly past half volume, is this just bad audio from the video or the DSS not been able to power the headphones properly?

The ATH-M40x's are very easy to drive, so it's probably not a power issue. Sending me a link to the video where this issue occurs can help me. You could also try plugging the headphones directly into the computer and see if it's a problem with the DSS (I have a suspicion that this is causing the issue).