Hello and welcome to Apple Support Communities Lroosth,
Thank you for contacting us regarding your AirPod Pro's. You have come to the right place and we are happy to assist you. If we understand correctly, you hear bass more prevalent in one than the other. We can understand why you’d reach out for a solution. It looks like you came to us from a resource that could help if one AirPod isn't working as expected. To verify, does this happen during Active Noise Cancellation , Transparency, or off? Also have you tried the steps outlined in this resource?
If Active Noise Cancellation isn't working as expected on your AirPods Pro
Change noise control modes on d with iPhone
"Control spatial audio on AirPods with iPhone
When you watch a supported show or movie, AirPods Max (iOS 14.3 or later) and AirPods Pro use spatial audio to create an immersive surround sound experience. Spatial audio includes dynamic head tracking. With dynamic head tracking, you hear the surround sound channels in the right place, even as you turn your head or move your iPhone"
Thank you for contacting Apple Support Communities.
Best regards.