Why is my mic so quiet?

I bought a USB microphone off Amazon (~$130). The sound quality is great, but it is very quiet - with the input volume slider in System Preferences all the way to the right, my other mics (like the ones in cheap webcams) have sound bars that go all the way to the right when I talk 2 feet away, while this one, right near my face, is only hitting the first few bars of the volume scale. The company has replaced it, thinking it may be a bad unit - same exact outcome. Is it really the hardware, or is there some setting somewhere I am not finding? (OS 10.14 Mojave)