Do subwoofers really help?

Thanks everyone I found a solution.

I'm sorry.
Am I missing something here? Did BobRock read the many answers to his question?
Replacing speakers with less sensitive ones resulted in more bass?
what?
And just what WAS the solution? I'd like to know, especially if it was something silly like just a setup issue. If he fixed it by throwing more money at it, that's a horse of a different color.

I actually took everybody's advice. The problem was the impedance curve on the speakers was too steep for the amp, but I liked the amp better. So, I sold the speakers and Got ones that better match the amp. The peak output on my amp is 4R. The impedance on my new speakers never drops below 4R so there are no issues. I can tell this was better than adding a sub because now I do not have to turn the dial on the amp as high to play them loud. Sorry for not being more specific I am sure I am not the only person to have done this.

I spent no extra $$ to do this I got good $$ for the speakers I had.