I have to tell you that at least some Monster Headphones are not working on a N9.
MONSTER Beats Tour by Dr. Dre MONSTER Beats
Sennheiser, Sony and even Apple Headphones are ok.
Does anybody know if other producers are affected by this?
Just to confirm Monster iBeats are also not suitable for N9 - the box does state 'made for iPhone' so be aware in case you decide to purchase these. I use 'em for iPhone n iPad so tried 'em in my N9 and can confirm they don't work. It's a pity, coz they are great headphones and N9 delivers in video n music department.
As N9 has the older Nokia 3.5mm AV OMTP connector rather than the AHJ/OMTP composite one upon Lumia 920/820 you may need to use adaptor such as: http://www.meelec.com/MEElectronic_TRRS_Adapter_fo