DE Mazda2 Audio Upgrade Question -- Speakers only, or Speakers + HU?

As good as our little Mazda2 is in numerous other aspects, I think a lot of us will agree that the factory speakers are just down right horrendous. Typically, I don't mind them that much because I mostly just listen to the AM radio, but yesterday I have decided to put some music on for my day long, city-wide run-around trip, and omg... I can honestly say that I have never, EVER listened to a factory stereo that sounded so bad in the past. The sound was just ugly and muddy, and there is absolutely no clarity at all. Even my wife who has never been picky about any audio equipment noticed how the sound sounded like someone was talking / singing with their mouth muffled as though someone has put a hand over it. The clarity is just nowhere to be found -- not even the littlest trace of it.

From digging around on the M2 audio section, it seems pretty clear to me that the factory paper speakers are garbage. What seems less obvious to me is whether the HU is passable / acceptable to an average person with some typical music preferences. I am not looking to sink any serious money into having a full aftermarket HU + amps + crossovers + high $$ speakers in a car -- I just expect some basic clarity to be present when I am driving around.

Do we know what brand / model the factory HU is, and whether it is any good at all? I am already planning to pick up some basic 6.5" speakers in the $40 range to replace the factory garbage. If I can avoid it, I'd rather not upgrade the HU as well since my initial research suggests that an HU install on the car be a bit of a pain. If the HU is junk as well, however, I'd rather order everything all in one go to save some S&H.

Last but not least, do we have a speaker and/or HU photo install guide on the forum from those of us who have done the same upgrade in the past? Knowing the plan of attack beforehand could make the job a LOT easier.

cheers and thank you for your help.

I'm actually fairly surprised by your conclusions, as I've driven cars in the same segment that didn't sound half as good. To be completely honest with you, the headunit is what's holding the sound back. Replacing it with a better HU, actually improves the sound a decent amount, though not quite as much as a speaker upgrade would cost. Depending on which speakers you get, it might actually be a better idea just to keep the OEM ones. On top of all the neat little features a new HU could provide, most also throw a bit more power at each speaker.

That being said, I have supplemented what I felt was lacking with the stock stuff by throwing a 12" sub in a ported box in the trunk, though I'm sure my music taste isn't quite the same as most here. (evil)

Yeah, it's the stock headunit that's really holding it back. Although the speakers aren't doing it much help, either.

After putting a headunit and speakers into my car, I can confidently say it's a lot less work than it seems. The worst part was creating the wiring harness, but that's because I'm obsessive about my solder joints.

I replaced the speakers before the HU, and doing that is definitely enough for a casual listener. I threw in my old HU mainly for Bluetooth and calling, and it does sound better with the replaced HU, but the speaker upgrade was more effective for me.