my iphone 4 sounds soft when playing songs with ipod

[jyan5501]

Hi guys i'm having a problem with my iphone 4. My iphone 4 tends to sound softer when playing songs with ipod. I have compared my iphone 4 with my 3gs and my 3gs sounds much more louder and clearer when playing the same songs (same kbps) and same volume. Even when i compare with my friend's iphone 4 their phone do sound louder than my iphone 4 with same song and same volume. Even my iphone 4's unlock/lock tone and typing tone also sounds softer than my 3gs. But when i'm comparing the ringtone volume for both phones guess what my iphone 4 sounds much more louder than my 3gs even though both are using same ringtone and same volume. So should i send it for warranty claim? It is really a weird problem.