I think you may have been on to something with the Rogers box, I went back through the settings and came across something called "Range", which I had seen before but really didn't know what it was. So for the hell of it I changed it, there were 3 options - normal, wide, and narrow. I changed it to narrow (it was on wide). That seems to have increased the volume by double.
Thanks for your help, sometimes just going through some options gets to the root of things.