#sound {
    background: url("../images/sound_1920.jpg") center bottom  no-repeat;
    height: 850px;
}

#sound .frame {             
    padding-top: 85px;
    text-align: center;
    margin: 0 340px;
    width: auto;
}

@media screen and (max-width: 1366px) {
    #sound {
        background-image: url("../images/sound_1366.jpg") ;
        height: 726px;
    }
    #sound .frame {         
        margin: 0 200px;
    }
}

@media screen and (max-width: 960px) {
    #sound {
        background-image: url(../images/sound_960.jpg) ;
        height: 560px;
    }
    #sound .frame {        
        padding-top: 50px;        
        margin: 0 15px;
    }
}

@media screen and (max-width: 640px) {
    #sound {
        background-image: url(../images/sound_640.jpg);
        height: 486px;
    } 
    #sound .frame {             
        margin: 0px 35px;
    }
}