it doesnt matter what you think a cab will do.. the speaker inside your phone wouldnt even be able to produce HD sound.. phones have a tweeter in em thats about it...
which means your only going to get the kind of sound reproduction youd get out of a set of "highs"... youd need a good 3 or 4 way speaker in a phone to fully process HD audio id think..
a cell phones speaker is probably at 30 OHMs.. thats high as hell.. cars and house speakers start at roughly 8OHMs.. thats why car speakers for systems get bridged down to 2OHMs, to increase the bass..
your phone speaker isnt going to give you a "rich, deep bass experience" no matter what you do to it... aside from changing the speaker