Thanks for getting in touch with us though apologies for the speed issue.
I have checked our data, dating from the 12th up to today. I can find no problem with noise, which was my first thought, and no other related network issues reported. Tests of your connection show that power levels etc are fine so no obvious problem with your Hub.
Thank you for trying a number of things your side though it's a shame it hasn't helped. If the speed is still a concern would you do me a favour please and disconnect all devices from the Hub bar one. Ensure that nothing is connected via wireless and connect the one device via Ethernet cable.
Now run a speed test via speedtest.net and post the results on here (masking any personal info first). If the speed is fine please disconnect that device and connect another in it's place.
I'll await your update on here and see if we can help further if needed
about 18 hours after posting this the service returned to normal. Which is great, but I'm still at a loss to the cause. AFAIK nothing had changed with regard to the cable run, so I'm gonna blame Squirrels addicted to netflix breaking into the comms box and stealing all my bandwidth.
Hehe, well if the squirrel looked like the one in the pic below I shall have a strong word with him (he visits my garden cafeteria for lunch).
Glad everything's working for you now though. As I've said I was unable to find any issues on the network for the day prior to you posting but if the problem recurs do please post an update and we'll take another look for you.