You know what, afer seeing your room I wouldn't be that concerned, the child is going to go after all those books,cds, dvds you have on the shelves and the doors of the tv stand. My oldest was fascinated by the glass doors we had on our unit. With the speakers at the front and near the shelving the chances are very slim anything will ever happen as he will most likely grap the nice hand holds on those shelves and pull them over long before he pushes over a speaker
I can picture him wondering around and pulling himself up on the shelves and as long as the grilles are on he won't think twice about them and leave the speakers alone, it would be the shiny drivers that would instantly attract him to the speakers should the grilles ever be off. Oh ya, I would keep the top of the speakers free of all items for awhile, especially that plant, really nice for grabbing, but you already now that.
