Mystery red line

[Thaum]

Hi folks,
I have had my Muse S for about 10 days, and have been learning to use Mind Monitor. Thank you for a great piece of software.

I see on one of the streaming graphs that there is always a red line printed between 40Hz and 56Hz. (I've attached a pic)

This happens without exception, so I am wondering if this might indicate any of the following:

1. I'm doing something wrong with fitting the sensors (I am wetting the sensors a little before use, but have also tried it dry).
2. I am doing something wrong in how I have Mind Monitor set up.
3. There's a consistent issue with the sensors, suggesting I should get a replacement.

I'd appreciate any insight anyone can offer.

Thanks.

[James]

That's a 50hz power line. Move away from your floor lamp

[Thaum]

Hmm,
No lamp on.
Makes me wonder if there are other electric devices nearby when I meditate.
I have to say, first thing in the morning when I meditate, the only electrical thing near me is my Android smart phone on which Mind Monitor is running.
The only other things I can think of are:
1. A PC computer and monitor switched on in a room upstairs.
2. Wifi box and router in the same room as me when I meditate.
3. flat screen TV, and related things on standby power in the same room that I meditate.
4. Cordless phone plugged into the electric supply in the same room.
4. Fridge connected to the mains in the next room.
5. Electric heat mat (for brewing kombucha) in the next room.
6. I am wearing a Garmin sports watch when I meditate (it's electric with wifi connections etc like a 'smart' watch).

As you have probably gathered by now, I have no technical knowledge in this matter.

Any tips to track down this interference?

Thanks for your reply, much appreciated.

[James]

The Muse and your phone are wireless, so you can just walk around your house and find the source by looking at the live chart, it'll go up and down as you move nearer and further away. 50Hz is mains power, so it'll be something plugged in. In my experience it's usually a light bulb.

[Thaum]

I switched off the mains power this morning (I am in the UK with a relatively new system (13 years old) running on an RCD distribution box.
The interference stopped with the house power switched off.
The interference re-started when the house power was restored.
I then switched off every appliance one-by-one, but did not find the source of this interference.

I shall try walking around the house to see what I can find.

Thanks for the advice James - much appreciated.