iPhone 4 and Equalizer presets

Hello Everyone, First of all, I'm using an iPhone 4, have iOS 5, and I'm using Voiceover. I have a questionabout the iPhone's Equalizer. Is it just me or does the equalizer in the Music settings not do anything? I'm perfectly willing to accept that it's just me and I either need to get my hearing tested or pay closer attention to the subtleties in treble and bass adjustments. Seriously though, I've gone through all the presets to see if any of them could make my music sound any better and I'm honestly not noticing any difference in sound quality. I've tried it while using headphones and while having my iPhone connected to my stereo. Am I doing something wrong perhaps? All I did was double tap on one of the presets and exit out of the screen. That should be sufficient to making the change, correct? I'm just wondering. I always enjoy playing around with equalizer presets when they're available on music devices or within software. Any help or advice would be greatly appreciated. Thanks.