yeah, that makes sense now! its probably because you are expecting them to be low bassy, they wont be when used with crossovers, thats the reason for crossovers, they cut out the very low bass notes, some of which the speaker can produce if used without crossovers, but it is better of not doing so!
speakers without crossovers will produce all of the spectrum of sound which they physically can but it is not best for performance.
They will be producing the best sound quality they can, especially when they are amped.
amp them properly and you will notice a very big increase in quality and (mid) bass response.
The misunderstanding with aftermarket HU's is that they increase the power to a point where you need to replace the speakers, this is not usually the case, HU's are ment to be a stand alone upgrade, by this I mean, use with stock speakers and you should notice a boost in quality ( unless the stock speakers are very bad or in an old car)
aftermarket speakers are another level all together and HU amps are not powerful enough (in general) to drive them.
like I said in my above post though make sure the + and - are the right way around or this will cause you serious problems, its hard to tell your exact problem without hearing it.
It will be one of those 2 things though and there is an easy way to tell if the + and - are the wrong way round if your unsure but dont want to remove the speakers just to check. (ill tell you if you are unsure.)
to sum up! ( sorry to go on!) I would get an amp depending on your componant set, If you want some advice on what amp then post a link to your componants, let me know a budget, and ill have a look around.
