Why is the music only coming out faintly?

A few days ago i plugged in my iphone to play music on my ihome. But this time the sound was different. I had the volume all the way up but the sound coming out was low and wasnt the normal im used too. It was very faint and not a full sound. Its very hard to explain, but both the volume on my phone and on the ihome were turned up and still the sound wasnt full.