Muffled quiet speaker even after speaker replacement.

Hello, I have a iPhone 7 plus that has a muffled quiet bottom speaker. The earpiece speaker works fine but with the bottom speaker so bad the audio sounds very tinny. I have replaced the bottom speaker with a new one but its still exactly the same as how the old one sounded. Any idea on what I should try next, I’m fine replacing any part just don’t want to do things that are not needed again. Everything else works fine the microphones are fine I can’t find any other fault with the device bar the speaker.