I wouldn't trust in headphones only while mixing. They don't give you a feeling for the depth, the "room" in your music and you can't feel the bass in your body Also the stereo-positioning made with headphones will first sound bad on speakers and its difficult to give the right amount of fx like reverb or delay. Good mastering won't be possible with headphones only. Main problem is that your face, head and body is excluded with headphones but important for sound-reception. They can be good for special tasks tho.

But if you want to make good mixes that sound good on all systems try to get some monitors. Its worth waiting until you have the money. There are also cheaper ones like Behringer truth, tannoy reveal or alesis.

I know that there are some guys who work with stereo-speakers but you have to know them very well and experiment alot to get good results that sound good even on different speakers. And nevertheless you will have to listen to your mixes on your friends studio-monitors Because HiFi-speakers are designed to make the sound _good_ (pushing up Hi's and Low's for example) while monitors are made to sound _objective_ . So on them you can hear what your sound is really like and then make it sound good.

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