Hi Damon 88! I am very experienced and I can help you. Read my article below how to archive "perfect" bass on IEMs.
All players and headphones are deficient in pitch and harmony. Plus, the sound engineers master their final songs assuming that most people will use EQ, for example, IN ROCK POSITION ON IPOD or V-Shaped or U-shaped (bass and treble gain) in receivers etc. Through the times, they create songs with these kind of EQ in mind. So equalizers are necessary to correct the pitch tones, no matter how expansive your equipment costs.
All MP3 players and DAPS are deficient in SUB BASS VOLUME and in many other frequencies, no matter the AMP YOU USE. The sound will never be LIFE LIKE WITHOUT EQ.
The FIRST TECHNIQUE is to increase Sub Bass Frequencies. Use Cowon Players for example. Pick The 50Hz Band, increase to at about +6DB. Then, begin LOWERING the mid bass and mid frequencies. Then, increase the HIGHS and INCREASE THE VOLUME. The more contrast you have between SUB-BASS (50hz) AND MID-HIGH-BASS (200hz) , the more life like bass you get.
Trust you ears to shape the sound as you like or as you think it is closer to what is heard on a live show. The more you play with the bands, the more experienced you become and easier it gets.
It is an ART and a Hobby that can make your sound TRUE TO THE ORIGINAL, AS THE ARTIST WANTS and everybody wants too :) It is going to be like a CONCERT HALL AND A SOUND STUDIO IN YOUR EARS !!!