Hello, I have no clue about car audio. All I know is that I have a 2000 Mustang with a Mach 460 sound system. It is awesome. A month ago, my factory CD player died, and today I had a Pioneer installed. The sound quality totally sucks now and I asked the guy at the audio shop about it. He said that I would have to get an amp for $350 to get that awesome sound quality again. I don't know anything about car audio, but is he telling the truth, or is he just trying to get some more money out of me? I am tempted to do it just because I miss my 460 quality so much, and the sound is so bad now. If anyone could help me, I would greatly appreciate it! Thanks guys!
sounds like a matter of eq. many of the stock units have an auto eq that, for one, attenuates the bass as the volume is increased in order to make the factory drivers sound like they're really doing something (without blowing). this factory internal eq also helps out in other ways, but basically it's a cheap option to make inadequate speakers sound better than they really are.
For speakers? JL would be my first recommendation, especially if you can afford the XR series speakers. Eclipse and Infinity are also nice speakers that would fit in your budget...
The factory radio had outputs for the 4 corners and a separate mono output for the sub woofer system. It sounds like the aftermarket system was never connected to the sub woofer system. This can easily happen since the sub represents a 5th channel and aftermarket head units do not account for this. If you liked your system so well, why don't you restore/repair it? I repair car stereo, and I can tell you that repair is almost always the lowest cost option to solving factory sound system failures.
The 460 sound systems are amped the amp was located in the middle of the car behind the stock radio when they changed out your head unit they probably by passed the amp cause it takes less time to install that way instead of figuring out the amps wireing