This area became a bit of a minor bashing for Apple over that. My answer is just from memory. That is, it's not like a stereo set of speakers. They do differ. You can google more about it but this is my fast answer from memory.
If you need a stereo player, add some external speakers or headphones.
I’ve bought a used iphone 7 plus now I know that it has a stereo speaker system. But I’m a bit concerned about it’s sound output, the bottom firing speaker works perfectly fine I’m just a bit curious to know that does both of the speakers sound the same or the speaker attached to the earpiece is a bit lower in volume.
Please help me with it!!!!!!