I'm sure someone can do more justice to this than I can, but after reading the description of the "volume booster," it seems that this is only meant for things like hearing conversation in noisy environments. Sort of like a hearng aid I guess. It is certainly not an "audiophile" device. Keep in mind that we can hear frequencies from 20 - 20,000 HZ. This device only responds to those within 150-10,000. Based on this, and the description given on the Radio Shack website, this devise is probably designed to amplify only the spoken word. It will literally cut out half the music if used as a headphone amp! This much I have always found to be true - you get what you pay for.