DAMNIT! I wrote this big huge long reply that explained why getting decent bass out of a 3" speaker is futile but IE crashed and it got lost. So let me try to remeber some of it.
if you halve the cone diameter you quarter the speakers ability to move air and create bass. so the speaker would have to work 400% harder(throw farther and do it more quickly) and this just isn't possible.<-- period
6" speaker minimum. And not jst any 6" speaker..one with a 5" magnet and weights 7lbs..like this one.
Elemental Designs: Car Stereo, Home Speakers, Electronics
This 6" speaker is one of a few that is actually designed to be ported at 30-35hz which is deep base.
99% of even 6" speakers are just not designed to create much bass before the voice coil, cone, and surround just starte creating distortion because they cannot keep control of the cone at throw lengths required to create bass. There are a few here and there that are intended to .and can handle it..but you will not see that in a 2-3" speaker at all. Its really a mechanical problem and a problem of physics trying to create sufficient airmovement/vibration to output high decibles at such low fequencies. you can't..by mechanicals just go make a 6" speaker than has 4 times longer throw to make up for the loss of cone area vs a 12". Remember even at 30hz you still have to physically move the speaker in and out 30 times per second. Wich is why large speakers don't make good high fequencies. Inertia. it is a *****.
All that being said I can tell you a few things. As audioguru and others know. a solid 50% of how your speakers sounds is how it is installed. How it is boxed, and ported/not ported. It doesn't stop there either placment of the speaker makes a big difference as well. I had a car stereo with one 12" speaker that was so loud that that it would actually create enough bass to flip the turn signal in my car on when I played "brass monkey". but ONLY if the speaker was pointed toward the back end of the car.Beyond all that you need a clean signal from the reciever to the amp and then a decent amp.
The best responce you can get from a small speaker under 6" is probably to try and copy bose waveguide technology. Transmission line box or tapered quarter wave box. All of these end up being large boxes so if space is the issue this is not a good option. good luck. I hope I didn't leave anything out..lol i'm sure I did.