i have these in the 6 1/5" and i am verry happy the guy at the car store i went back about 2 months later and he ask how they going and i said i am thinking of upgrading to infinity or MB Quarts he ask which MB Quarts and i said the DSC blah blah blah ( not sure on the model number) and he said dont know if he was just being a sales man even though he wasnt selling me anything that the alpine ones are as good os the DSC MB Quarts