Problems with iTune radio and Airport Express

I use iTunes and Airport Express to listen to iTunes radio stations through my stereo. Reception is, unhappily, very spotty and not the best fidelity. Lower frequency sounds are very boomy for instance. More important, I often cannot listen to a station I've chosen because it either won't tune or keeps cutting out. This afternoon most of the stations I tried to listen to produced only quick blips of sound. I left one station on for a quarter of an hour and the blips continued pretty much the same the whole time. Is there any way to make this set-up work more consitently and give better sound or have I just wasted my money?