wireless is super-slow compared to macOS partition | Broadcom BCM4331 | MBP 10,1

[bennywas]

Hiya!

Issue
My wireless connection on my new Ubuntu partition is so slow compared to my macOS partition. Speedtest.com results from two different wifi locations confirms this:
(Location. Test: Ubuntu result macOS result)
Public library. Ping: 52ms 9ms | Download: 4.80Mbps 7.33Mbps | Upload: 4.26Mpbs 7.36Mbps
A local cafe. Ping: 24ms 30ms | Download: 2.80Mbps 48.90Mbps | Upload: 0.96Mbps 11.64Mbps

I'm at the cafe now, and wifi does work albeit rather slowly, but trying to run the wireless info script from terminal returns:

Resolving github.com (github.com)... failed: Connection timed out.
wget: unable to resolve host address ‘github.com’

So I ran the script again while tethered to my iPhone (I mention this because I'm not sure if it makes a difference for the data collected). The results are here:
http://paste.ubuntu.com/p/b9nCvHNgjN/

Background
This is a MacBook Pro 10,1, with a macOS partition and an Ubuntu 18.04 partition. When I first installed Ubuntu last week, I had major trouble just figuring out how to get the wifi functional, but I eventually solved it by following this advice to install the "firmware-b43-installer". Now that I can connect, the next step is figuring out how to speed up my connection to comparable levels to my macOS partition.

I'm new to Ubuntu and relatively new to command line, FYI. I'd appreciate any help on starting to diagnose or possibly fix this problem! Thaaaaaaanks

[bennywas]

Should I have posted this somewhere else? Did I include too much info or not enough? Did I use the wrong tags/descriptors? jw why this post is getting no love...

[praseodym]

Try the fixed channel "11" in your router. Channel 1 is crowded, higher than channel 6 will cause interferences with 6. Set the bandwidth in your router to 20MHz instead of 20/40 MHz.

[bennywas]

Hi praseodym!! Thanks for responding. I actually don't own a router. My question is about the wifi I connect to on a daily basis, which is public / cafe wifi.

Besides, even if I could approach the manager of every cafe or public library I enter to ask if I could please mess around with their router, that doesn't seem like the real solution. As I said, the wifi connection works fantastically on my macOS partition at the same location, whereas the Ubuntu connection is crappy. In my original post, I cited two identical locations where I sat down to compare the wireless speeds of each partition at the same time of day. I've since been to several more public wifi locations, and comparing the signal strength across the two partitions/OS's, the results are the same: wherever I go, my Ubuntu partition's wireless connection is significantly slower than my macOS partition's wireless connection.

What do you think could be causing this? How can I diagnose/remedy it?