Question regarding the speakers on my Mac

As I can’t seem to run the apple hardware test as it gives me a load error. I have been thinking about replacing the speakers in my device. They still work, but the volume on them is not what they used to be. When I first bought the MacBook back in 2012 the sound coming out was louder, crisp, you could use it to listen to music or watch movies. These days however, I can have it turned up full and its hitting no where near the volume it used to.

Is this an indication that the speakers might need replacing or (as I read elsewhere) could it be to do with the later versions of OSX throttling the volume on the device?.