[Abouna]

OK, so I don't use my 5X with headphones much but when I have I've noticed I get very little volume.
 
I'm just wondering if I've got a bad phone, headphones or are these just hard to drive and the 5X sucks?

 

[wskl]

The headphone out is not very loud according to GSMArena
http://www.gsmarena.com/lg_nexus_5x-review-1338p7.php
 
Also, if you check PhoneArena benchmarks -> Audio Output - > search for Nexus 5X
http://www.phonearena.com/phones/benchmarks
 
You will find that they measure the headphone out as 0.287V which is not very high.  I recall reading that you can get reasonable volume with 0.5V output but a smartphone closer to 1.0V or higher is considered very good.
 
Hope that helps.