For testing sites on lower bandwith, you can also use Chrome Developer tools. (Press CMD+Option+i to open it in Chrome). From there you can see the bandwith option under Network tab. I made an illustrative GIF -> http://kldr.co/BjtwFA (sorry it got pretty big, might load for a while).
If you need any help further, feel free to email me at email@example.com and I can help you out.