Well I can see your biggest problem is that your using Quick Hit doses which are intended for advanced users only so that the advanced users can acquire the same effects in less time. Quick Hit does NOT mean its more powerful by any means so you have to give up the quick hits and buy full doses. I highly recommend A-Bomb
viewtopic.php?f=2&t=10334 as a good choice for beginner dosers. A lot of newbies have good results with this one. Try to follow condition with it too. Condition is an excellent tool for both beginner and advanced users to experience IDosers power.
Now if A-Bomb doesn't work it doesn't mean you are immune. There can be multiple issues and you just have to figure out what it wrong. You asked about your headphones and to be honest we can not answere any headphone questions. We simply don't know. IDoser doesn't know. But if you want a pair of headphones that work get it from the list of recommended headphones.
http://i-doser.com/about.html I have also writen a guide to picking out a pair of decent headphones that will likely work.
viewtopic.php?f=1&t=10385 It could also be your meditation. Even if you are doing everything right your mind can be clouded and render you unable to dose.
viewtopic.php?f=1&t=10307 Here is a guide I wrote on meditation. A clear mind is the main key to dosing and having the best effects. A lot of users say focus on the dose. DONT, You need to have a completely clear mind for the best results.
It could also be the dose you are using. Like I said QH don't work for newbies as well as they would like them to. Always start using Full Length doses. Play around too. A-Bomb is great but that doesn't mean it will work either. Pick out a hand full of doses that suit what your looking for in a dose and keep trying. Some dosers don't get IDoser to work for a couple months but then they finally do when they try a certain dose.
I hope you find this information helpful to you and good luck with your dosing experience.