Each and every speaker has a different voice.

I get a lot of questions about satellite speakers (also know as mids' and highs'), specifically, which ones are the best. Every speaker has its own voice, they sound very different.  Music is a subjective experience and every persons ear hears something different.  A good objective test can be done by playing pink noise in a speaker (sounds like static, but it is all frequency's represented at the same level at the same time.) then we look at it on a RTA meter. 
    The issue with this is that sound of a speaker is affected by the enclosure (often a door) it is in, and the environment that it is playing into (the car cabin) neither if which is a constant from car to car. So what you are listening to in the sound room may give you an idea, but it will sound very different once you get it in the car.
    So how do you know what is the best speaker for you. As I said you can get a good idea by listening to it in a sound board (at least they are a constant in the sound room.), but find a good salesmen (not a salesmen trying to sell you what ever he has a stack of in the back) and talk to him about what you are listening to and how the car might affect the sound.

i.e.

• Convertibles tend to sheer off the highs a little more then a hard top car.
• hatchbacks, and suvs usually build bass a little better then cars with trunks or convertibles.
• Speaker placement is important too, if tweeters are pointed right at you they tend to seem brighter and image better then ones that don't, but the pitch of the dome of some tweeters (and the design of some crossovers help to compensate for off-axis listening).

    I could go on and on (and will if you come in the store and let me).  I want to stress one very important thing.  If you go to a car audio shop and audition speakers give the salesmen an opportunity to sell you your gear.!!  (but I can get them so much cheaper on ebay, or amazon, or craigslist or sonix's) I know, I know but I have several great reasons why you should give them the opportunity (I will explain the opportunity in a second but first lets look at why you want to buy local).