Laura,

i built some speakers recently, if I had damaged the drivers while doing
it, would it be obvious?

If you didn't actually saw into the speaker cone, or bend the frame out of
shape, then it's probably still fine. Listening to only one driver or the
other won't hurt anything, though you should never send low frequencies to a
tweeter without having a crossover connected. Sending high frequencies to a
woofer should be okay, even without a crossover.

I used to work for a large speaker manufacturer and every driver was tested
by playing a sine wave that swept through the driver's normal operating
range. So if you have access to a sine wave generator or test tone CD, you
can verify that the speaker is okay by slowly sweeping a tone at a moderate
to semi-loud level. What you're listening for is buzzing or obvious
distortion, and you sweep across a range of frequencies to make sure the
driver is okay at all frequencies. For a woofer you'll sweep from it's
lowest rated frequency up to maybe 1 KHz.

--Ethan