Robin wrote:

Just purchased new 2004 car that comes with Infinity stereo speakers.
Don't know if its true but I'm told if I were to pop the speaker off,
I'd find it's a JBL as is the stereo. It's this car make's top of the
line stereo they offer, yet it's horrible.

No, it's infinity. But Infinity(speaker brand, not that car) owns
JBL, so...

Of the factory stereos, the Infinity are by far the best out there.

What exactly is the problem? My guess is lack of bass, which can be
solved by a small subwoofer. IME, they certainly don't lack high-end
response.

It has one of those equalizer
where you choose Rock, Classic, Jazz and the only setting that get's any
kind of passable sound is to use Rock for all music genres. If you don't
use the equalizer setting, forget it - it fades into the background.

Ah - the speakers are likely fine, then - it's the brain dead POS
factory stereo. A good Kenwood replacement would likely solve
the problem - and play MP3 cds as well. I'd do this first and
then worry about the factory speakers.

There's not much separation of sound, it's flat,a lesser quality of
sound than the standard stereo which came with my 2001Honda Accord EXLV6
which this new car replaced. It's probably obvious that I'm not an
audiophile, but I know what I like to hear, and this stereo is just flat
and lifeless.

Yep - a poor head unit/amplifier will do that. It's really not the
speakers if they are made by Infinity, as they are comparable to
aftermarket Kenwood or simmilar speakers that you see in all of the
various car audio stores. Alpine are simmilar as well.

Go to Al and Ed's Auto Sound(local So. Cal. Chain)Alpine, Kenwood,
and Infinity account for 75% or more of the speakers they sell - and
thee are the same ones in your car. Note how much better they sound
in the store. Same speakers. That leaves your amplifier and of course,
background noise, which will sap low frequency response like a sponge.

A sub fixes that instantly.

I've asked some opinions of other people, some suggest buying a new head
unit before investing in speakers; while one other person said this:
.....replaced car speakers with two Alpine 3-way 6x9 speakers. The
change exceeded my expectations -the bass and clarity was astounding!

Ah - this gets back to my original observation - the bass.

1: Replace head unit. Kenwood and Alpine make decent radios.

2: Add a subwoofer if necessarry. It need not even be a large sub,
or even lound - just something for low frequency blending/reinforcement.