They are actually the opposite. They could be tipped over forwards or backwards when the woofer box is not in place, however the bridge is shorter than the front or back of the woofer box and when it is in place it is almost impossible to actually tip it over as it bangs into the woofer box. With two 10" drivers in each one the woofer box weighs somewhere in the realm of 30Kg and is not easily shifted. The same applies to left right movement.It also looks like the slightest push could have the top part tumbling to the ground, do people weigh them down or attach them to the bass unit in some fashion?

In comparison to a bookshelf speaker on a stand they are quite toddler and animal safe.