Creative Labs claim they can upconvert music back to 24 bit audio. When I first heard that claim I thought it was preposterous. It's not possible to replace something that's missing completely from a digital file right?
Shortly after seeing an ad for the Creative X-Mod I saw one for sale at a local Best Buy store. It was $80.00. I was very intrigued by Creative's advertisement. But couldn't see how their claims could possibly be justified. So I bought the X-Mod on my credit card with every intention of returning it after trying it out.
The Creative X-Mod was marketed mainly for laptop users. If you sit at your desk all day long and use headphones to isolate yourself in order to concentrate on your work - like many programmers and graphic artists do - then the Creative X-Mod will greatly add to your listening pleasure.
The Creative X-Mod upconverts music to 24-bit audio and fills in the missing gaps in lower and higher frequencies. There is no interpolating going on. Creative states that their sound engineers have come up with a way to identify instruments and restore the data that's lost during compression. It does more than boost frequencies. Bass is lower, and highs are cleaner without jacking up levels.
Over the years creative has made newer variations. Their latest is here: Creative SXFI Amp
The music just sounds better!