The University of New South Wales in Sydney have come up with a very general, yet good test of your ears’ own equaliser settings. Essentially, it proves that while you can hear 30Hz – 16 KHz, you may find certain frequencies much louder than others. This test (link after break) should be taken in an absolutely quiet environment with the best headphones or earphones you own. However, most headphones, loudspeakers, et al., impose their own frequency responses upon your hearing. This test has not been formatted for your source or your headphones, so it can remain only a general indication.
If you have an external DAC/soundcard or a neutral musician’s amp, utilise it for this test. Keep track of your results for whatever headphone you test as each will have its own idiosyncrasies. This will help you equalise your music more perfectly for a specific headphone/earphone/loud speaker.
My test was taken in relative silence (though I live in a construction area of New Seoul) with Comply® rather than with silicon flanges via the Mingo WM2 inner earphones. When JH13Pro, Sensaphonics, FitEars and a few other higher end customs arrive, it will be interesting to see what sound signature they impose on my listening.
Remember: each listening implement has its unique sound signature which should not be universally applied to other implements.