I just tried to install the included carpet spikes on my R50s. They sit on very thick berber carpet over cement, so I thought that the spikes would be a good idea.
I turned over the speakers and removed the press-in feet. I then tried to install the spikes, but they are much to thick to fit in the given holes. I'd rather not be getting out my drill until I asked the question "did I get the right sized spikes?"