I don't know exactly when the gym actually opened, but, I think it was in 2009. I'm pretty sure that when we moved in (september 2009) the gym was not open for a long time.

In the beginning we didn't have any problems with loud music at all. I think the loud music only started sometime in 2013, I don't know exactly the date.

Since the user Pico said they recently installed club standard speakers, it all makes sense now.

I also sympathise with them, it's not like we hate them or want them to close. The last thing I want to do is to make an official complain, I rather just fix the situation over a conversation.

Answering Pico's comment, It wouldn't be a lot easier for us to move out. As I said, apart from this problem, I'm very happy with the flat and specially the area. We are having a baby and everything is already set. My wife is due in 1 week with our first baby and this noise problem and moving out are the last things we want to be thinking about.

I will pop in the gym, ask for the manager, have a sit with him and see how it goes. I know its a s***ty situation for both of us, but, at the end of the day, I believe we have the right to live in my flat in peace.

Thank you blushingsnail for all the information, that will probably help a lot.