Is the woofer in my MBP 17" broken? Help me test it !

Question

I have an early 2009 Macbook Pro 17". I had so far been using just the internal speakers for sound. Recently I plugged in a pair of $20 earbud phones and discovered how much I've been missing from the music! Using the earbuds, I can hear bass elements in music that I thought didn't exist. The MBP's internal speakers hadn't been giving them to me!
Obviously I'm no audiophile... I still don't have a good pair of external speakers. But I'm wondering if the woofer in my MBP is broken? (I understand that the MBP does have a woofer.)
I'd like to know if others who own 17" MBPs also feel that their internal speakers are disappointments. Or are you satisfied with their sound in the bass range?
To see whether my MBP's woofer is broken, I'd like to compare it side by side with another MBP playing the same music. But since I can't do that, _I'd like to ask the readers to run the following test on their MBPs, then reply to this post._
Download "AudioTest" from here: http://www.katsurashareware.com/pgs/audiotest.html .
It's a 485 KB nag-ware. It generates tones at frequencies you specify.
Please run AudioTest to play tones of decreasing frequencies. For example start with a tone at 200Hz. Then a tone at 180, 160, etc. _Please take note of the frequency of the tone that you cannot hear through the internal speakers, then please tell me what that frequency was._
When I used AudioTest, I set my MBP's volume control to less than maximum - i.e. 4 bars below maximum (I was afraid of possibly damaging the speakers.) Within AudioTest, I set its output level to -3dBFS. I used the Sine Wave Type.
With my MBP's internal speakers, I can hear tones (hums) at frequencies as low as 120Hz, 110Hz, then nothing. I cannot discern anything at 100Hz. This is very subjective, but discernability appears to drop suddenly starting at 120Hz.
Through my earbuds, I can hear/feel tones as low as 10Hz!

Answer 1

French Roast: The speakers in notebook computers — ALL notebook computers — are necessarily tiny, and are therefore severely compromised in their ability to reproduce sound faithfully, especially low-frequency sound. They are, to be blunt, not suitable for listening to music. They're fine for Skype calls, listening to recorded books or podcasts, etc., but if you want to listen to music, you need speakers or headphones.
If it were possible to get good sound out of speakers as small as the ones in a notebook computer, the subwoofer in a home-theater audio system would be no larger than a Pink Pearl pencil eraser, and each other speaker in such a system would be the size of two stacked nickels. That's not the case, and it's because speakers that small can't reproduce full-spectrum sound. So don't expect good sound from notebook computer speakers, and you won't be disappointed.