I'm buying an 04 WRX and I was wondering, what actually is in the upgraded stereo package? Like what company's speakers do they put in instead of stock, what type of subwoofer, how many watts, etc.

 

Subwoofer is small and only 120 watts. Anything that fits under the passenger seat can't put out that much bass. Some have been pretty happy with it though.

 

The speakers are plastic cones vs. the stock paper ones and are an improvement, but they are still full-range and not coaxials. The sub is a small 5" unit that goes under the passenger seat, the "120W" rating is deceptive as that is a "max" power rating that does not reflect the actual RMS output. It's adequate for bass fill but won't shake the ground.
Both of these "upgrades" are overpriced for what they are if you buy them from the dealer. If you check the Private Classifieds here and over on NASIOC, there are usually people selling both the speakers and subs for far less than Subaru charges. Or, you can just go aftermarket and get better stuff for the same or less money.
One caution, if you do decide to get a used sub from the classifieds, be absolutely sure it comes with the harness to install it, and that the harness is complete (connectors on both ends) and hasn't been cut. A replacement harness is over $100 from Subaru and can't easily be made by yourself.

 

for convenience the subbie OEM stuff is good, for sound quality is is on par with the stock setup, just a lillte cleaner, and a little bit of bass, but nothing well defined. You're better off upgrading your front drivers to something like diamond M3 series(or hex series if you really love yoru music), if you care about your rear passengers go anhead and upgrade the rear as well, personally I plan on changing them to a midbass driver. Then if you want quick and easy bass pick up an infinity basslink off of ebay for $185, spend $100 to have it installed and for around the same cost as the oem system, you have MUCH better sound and the people that sit behind the passenger can actually put their feet under the seat.

$139 6.5" Diamond M3 for the front http://cgi.ebay.com/ws/eBayISAPI.dll...704424093&rd=1
$119 5.25 Diamond M3 for the rear http://cgi.ebay.com/ws/eBayISAPI.dll...703777544&rd=1
$41 for WRX-THK speaker adapeter set from here https://w109.webminders.com/iaperfor...ctionNumber=59
and a basslink for a little depth $185 http://cgi.ebay.com/ws/eBayISAPI.dll...704547292&rd=1

you'd probably be charged $150 for installation, if you don't want to do it yourself(it's a cake install) and you won't believe the sound difference, the diamonds are sensitive enough that the stock deck will run them fine.

This would be for a wagon, if you have a sedan just go with a different rear speaker set.

 

ah ok thanx for the info, i was actually thinking about infinity kappa 2 way co-axials, how are those compared to the diamond m3's