I got my Shure SE215s today and I am wondering what volume level it is safe to listen at. I am using an iPhone 5 as a source and I read in another thread that the max Db output of the SE215s and an iPhone 5 would be at most 120DB and more likely round 100DB for most music. However, I have a volume limit set at just under 1/4 of the max volume and it sounds very loud to me so I generally listen at half this again. Therefore, I am only listening at around 10-20% to be safe but it seems like I would be ok to listen at 50% as this would only be 60DB max? I am worried about hearing loss as mine is not the best to start with, is there any way to ensure the volume is safe?