Not necessarily.... I have found that some of the Infinity speakers don't have a lot of low end bass response. They are clean and clear, but lack on the bottom end. I like to listen to several sets/models/brands in a demo wall. Even if the wall is IB or not built to optimum specs for the speakers, you can still get a good idea for how the speaker will sound once installed. Except you have to account for cabin gain below about 60hz compared to demoing speakers outside the car environment.
One of the best factory OEM systems I heard was in a '96 Cadillac... It had speakers that had the response of a typical 8-10" sub and highs that were clear enough to not need any additional tweeters. My friend ended up adding some 15" subs for the extreme low end but everything else was 100% stock. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif