I wonder if there is a limit on how many basstraps and accoustic panels you should use for a room?
I mean, could it be negative in having to many on your walls?
There is no proper amount of acoustic treatment for a room. It depends on what kind of room sound you're going for.
If you're going for a dead room, then no, there is no limit.
If you're going for anything else, then yes, there is a limit.
If you're not sure, there are two ways to approach it: