Conference Room Audio Quality

I am part of a Zoom group that meets on a weekly basis. The attendance is a mixture of individuals logging in from their homes and a group of folks that come together in person in a conference room setting. What I have noticed is that the voice quality from the conference room is all over the place depending on the characteristics of the particular person speaking. We have one male attendee whose voice seems to come through crystal clear even if the microphone isn't all that close to him. For some attendees who have higher pitched voices that are also softer spoken, the quality is terrible even if the microphone is right in front of them. The voice compression artifacts make them sound like they are underwater. Even if I crank-up the volume on my side, I still can't understand them. Other remote attendees have voiced similar complaints.

I understand Zoom has an HQ audio option in the control panel that turns off audio compression. I believe this is called "original sound". Does anyone know what kind of bandwidth this requires? I am thinking here of the performance parameters that can be obtained using an internet speed test (i.e. bandwidth in Megabits/sec and latency in milliseconds). Our conference room is connected to the internet via WiFi, which I know can be sub-optimal compared to a hardwired ethernet connection depending on the connection quality of the wireless link. I am just trying to get a feel for what sort of minimum connection quality we need to support "original sound" (assuming that helps solve our problem). 

The microphone we are using in the conference room is an Aluratek AUM01F which is a low-end (~$30) omni-directional microphone. This could be part of the problem, yet some attendees come through on this microphone crystal clear whereas others are extremely hard to understand. What I am hearing from the conference room attendees with poor audio quality sounds to me like it is caused by compression artifacts.

Thank you!