My bottom speaker is not working

Hi Ahmed,

Well, it seems we can be pretty sure something got either broken or shaken loose in the drop. There are three parts you're going to have to look at to figure out what's wrong with it.

The first is obviously the speaker itself; it could be damaged and would need to be replaced.

There is a guide available here in iFixit that will give you step by step directions on replacing the speaker.

iPhone X Lower Speaker Replacement - iFixit Repair Guide

Secondly, it's possible the connector for the speaker got knocked loose. This doesn't seem like a high probability, though, as it has a retaining bracket over the top of it to prevent just that sort of thing from happening. Regardless, you'll definitely want to check it and make sure it's plugged in solidly. Here's the connector you'll need to take a look at.

If you just want to check the connector, follow the instructions in the speaker replacement guide shown above and stop at Step 26.

The third possibility is that the dock connector that connects the speaker to the motherboard got damaged.

iPhone X Lightning Connector Replacement - iFixit Repair Guide

Personally, I would probably go ahead and replace the speaker; they're not expensive and it's one of the simpler repairs on an iPhone X. If that doesn't do the job, then the dock connector is the only other thing that's in the path between the speaker and the sound chip on the motherboard, so that would be what I'd replace next if a new speaker doesn't fix the problem.