Mac Mini 2012 Poor Wifi

Question

Hi All,
I've had my 2012 Mac Mini (the basis of my home music recording setup) about 9-10 months and always had poor wifi connection. Download speeds are terrible and it can take hours to download a few MBs
My provider is Sky Fibre Broadband with the Sky Hub. It's all less than 12 months old. It doesn't seem to have the 5ghz option that's been mentioned.
Another point to note is that the signal isn't trying to penetrate several thick walls, the Sky hub is in the next room less than 10 metres away with a direct line of sight through 2 doorways.
I've been through everything in this thread Intermittent and slow Wi-Fi connection on Mac Mini Solved! to no avail. I've tried turning off monitors, speakers, hard drives, bluetooth (even though I need to use this to connect my iPad for studio use). It's completely unusable. I even have the sky booster for the wifi sat  next to the Mac and it makes no difference. My Mac Mini is updated to latest OS X Mavericks which took a very long time to download!
The only thing left for me to try is running a long ethernet cable from the sky hub to see how it is wired. This I am going to do today when I'be been to buy a cable as it's not convenient and unworkable to strip down my home studio to move it to another room.
Yesterday I spent a long time on the phone to apple support and they seem to think there's a problem with my home network and interferance. We went through all sorts, deleting startups items, caches and so on
Although every other device in my home works absolutely fine. These include Windows 8 laptop, Google Nexus, LG G2 Android Phone, iPhone 4s, 2x iPod 4th Gen, Xbox 360, PS3, LG Smart TV, iPad Air. Note these aren't all on at the same time!
It did connect using the iPhone 4s as a hotspot to test which is why Apple insist there is no problem with the hardware, although the WiFi doesn't pick up any other local networks available for example my neighbours of which there are around 8 I can see on other devices.
Any thoughts?
Out of interest does anyone think getting an Apple Airport Express, connecting it to the Sky Hub but connecting my Mac to Airport rather than the Sky Hub directly would work? In effect creating an isolated connection from the other devices in the house? Maybe they will take to each other in a nicer way. I'm a bit confused by what I can do with the Airport and want to afford splashing out on different routers etc. Trying to get them to work on Sky I can just feel the headache!
Thanks in advance, hope the above is enough info

Answer 1

If you ALT+Click on the Mini WiFi icon in the menu bar, you should see a 'Open Wireless diagnostics'. If you click on it and press command+2, it will bring up a utilities window.
There are two functions that you should consider. Wi-Fi Scan and Performance. There is also Logging, Frame Capture and Info. You can look at these and analyze what may be issues with your Mini.