TINHIFI 5s

Hello, so the TINHIFI 5S was my first ever pair of IEM’s. I admittedly bought them without knowing anything related to IEMs. I absolutely love the way they sound however, I was noticing some issues; one side was far quieter than the other. I figured out the reason was due to the little filters that around the nozzle. I purchased some other filters but unfortunately the audio felt different, like there was’t enough bass or something. Is there a specific kind of filter I’m supposed to be buying and or using? I’ve unfortunately long since lost the replacement filters that came with the box (honestly don’t remember even seeing them.)