Sonic Defender
Headphoneus Supremus
Good to know - in my case I had to push the volume to roughly 80-90% of maximum to get a level of volume I found adequate for all types of music. Personally I prefer to have more headroom, 'just in case,' though that mantra may prove pointless and expensive in the long run... Lol!
All that said, the sound from the Asgard was quite good, just not my cup of tea signature-wise. I will say I preferred the overall sound from the Gustard X12 + H10 or the NFB-28. I didn't have much luck with the Mjolnir as it sounded a bit flat to me.
YMMV or course and this is all just my opinion - always try before you buy whenever possible!
My experience with the 560 and Asgard 2 was identical, often I had the volume on full. When I went to the Yulong A18 it was better with more headroom for sure.