Electronic – Speaker Frequency Range and Frequency Response

Every speaker works at every frequency, just that the efficiency falls off outside the rated range. You can make the cone of a subwoofer move in and out over its maximum travel distance at 2 Hz easily enough. The problem is that the displacement required for the same sound power goes up with decreasing frequency.

You can make more use of the sound power you do get out of the speaker by tighter mechanical coupling to the microphone. Mount the speaker on one end of a box pointing inward, and the microphone in the middle of the opposite end, which stays open. The wavelength for 2 Hz is about 165 m, so a box a few feet accross won't cause interference fringes off the walls, like it would at over a kHz or so.

Even if the speaker is out in the open, moving in and out 1/2 inch, and the microphone is a couple feet away, you have to ask yourself what you expect this microphone to pick up for real that would be louder than that. If it can't pick up this infrasound with 1/2 inch displacement, what is it going to pick up in the real world?

Another issue is that you will probably need to design your own power amp to driver the speaker. Normal audio amps have high pass filters that should attenuate 2 Hz severely.

Be careful with the power ratings of speakers. In the hifi community the power rating is not understood as a value where the speaker performs best. It's understood as a value which, if exceeded breaks the speaker or produces very bad sound results. When picking speakers, you usually multiply the power ratings by 3-4, just to be sure. Before searching for speakers check your amplifiers total output power!
Regarding frequency: 10khz is not enough for a decent music quality. Low quality audio hardware ranges from 50HZ - 16khz.
Decent quality would be 18Hz to 20kHz. Now, a single speaker usually does not perform well over such a wide range. That is why normal speakers are build of a tweeter (for high frequencies) and a woofer (for low frequencies). The woofer plays everything from 50-2khz, for example, the tweeter plays everything else. The signal is split with a high pass, for example.

There is a solution for that problem as well:
Look for a broad band speaker. They are usually ranged from 50Hz - 16kHz. They are not meant to play to loud, though.
One more thing: Keep in mind, that even if a speaker is rated as 180Hz ~ 10kHz it won't perform the same on all these frequencies. Some frequencies will be louder, others are choked. Check the frequency response diagram for the speaker if available.

Another solution:
Try finding PC speakers, somewhere. Maybe even old ones, people dump them everywhere, for no obvious reason. You might know someone who can give you a pair.