Users of AirPort Express may find that the standard level used for amplification of other connected devices (CD/DVD players, game consoles) appears to be different and higher than with AirPort Express. However, AirPort Express gets its volume level partly from iTunes; when you stream music, you can adjust the volume either on your stereo or within iTunes. Try keeping the stereo at the volume level you use for the radio or CDs and adjusting the iTunes volume so that it’s loud enough.
Why does my AirPort Express volume sound low?

Jeremy Horwitz
Jeremy Horwitz was the Editor-in-Chief at iLounge. He has written over 5,000 articles and reviews for the website and is one of the most respected members of the Apple media. Horwitz has been following Apple since the release of the original iPod in 2001. He was one of the first reviewers to receive a pre-release unit of the device, and his review helped put iLounge on the map as a go-to source for Apple news.