It's the same for my DM-40BT so I guess it's normal. I bought these https://productz.com/en/pioneer-dm-40bt/p/5a7pY white ones a couple of weeks ago and recently I noticed that my left speaker is a bit louder than the right one. But it doesn't bother me that much because the sound is perfect...
Left speaker DM 40 slightly louder then the right one
I bought these speakers years ago and only just realised the amp model is slightly quieter the the slave speaker is it normal ?