can you connect a 4 ohm subwoofer to a laptop

Solution
If you connect ANY POWERED speaker to a laptop that's not a problem, because the laptop doesn't "see" the speaker directly, it just sees the input to the speaker's amplifier stage, hence whatever ohm-age, is inconsequential to the laptop.

If you connect un-amplified, passive speakers to the laptop, you will find it sounds very weak. See, it's good enough to drive those little built-in speakers and that's it.
If you connect ANY POWERED speaker to a laptop that's not a problem, because the laptop doesn't "see" the speaker directly, it just sees the input to the speaker's amplifier stage, hence whatever ohm-age, is inconsequential to the laptop.

If you connect un-amplified, passive speakers to the laptop, you will find it sounds very weak. See, it's good enough to drive those little built-in speakers and that's it.
 
Solution