iPhone left speaker low volume

Welcome to the Apple Support Communities.

Go to Settings > Accessibility > Audio/Visual > Balance, and make sure it is set in the middle, not just to the left or right.

If that doesn't help, see: If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support.

Jack

As Lawrence Finch stated, there is no speaker on the left side of the charging port. The speaker is on the right side of the charging port, the grille on the left side of the charging port is a microphone.

If you mean on the bottom of the phone, there is no left speaker. The grille on the left is a microphone. The stereo speakers are the bottom right and the phone earpiece near the top of the phone.

I had a similar issue - my iPhone X speakers became really really quiet (to the point where I could barely hear the GPS over the sound of my car). I was strongly considering getting a new phone just because of this.

But yesterday I used a thin bristle brush (a toothpick would probably work too) to gently poke into the six speaker ‘holes’ on either side of the charge port. I was playing a YouTube video at the same time, and I could hear the volume get immediately louder as I was picking out the dust and fluff that had clogged the speakers. Now my phone is like new!

Hope this helps somebody.