i have a 97 deville im not sure what the stock system is..bose?? well anyway it use to sound real good and have bass but lately it sounds like it has no bass at all! do these systems have a stock amp that goes bad?? it almost sounds like i have a blown speaker if i turn the bass all the way up but its both that sound like it. so i turn it about 1/2 way and it doesn't have that pound like before. i heard something about these caddys having a cone setup?? i dont know any help will be appreciated. Also if i replace the stock head unit with an aftermarket one will i have any problems??? the steering wheel controls wont work i know about this optional peice u can buy but will it affect anything else??