No you are wrong. First the iPhone has to abide by a similar law which also exist in the U.S.and second the Galaxy S 4 sold in the U.S. has to abide by the same rules as the iPhone. The iPhone does have better sound quality, especially during calls, than the S 4 but it sounds like his loudness issue is a defect of his particular handset.
Originally Posted by chanchan05
Umm, yes. This has been an issue since 2007. This complaint first cropped up against Nokia who were number 1 then, when their phone music volumes started dropping. Many manufacturers started following suit until only Apple remained as the loudest in terms of volume output among all devices. Samsung does have a SoundAlive externalization setting to overcome this when connected to speakers though.