Mkaes, I can't say for sure. One set certainly was what they recommended for a tube pre-amp. These I had lying around. A bought another set of 3 just to complete the set of 6 for the 2 speakers, so it's very possible I was mix and matching 3's and 4's. If you don't mind experimenting or you can return the cones give it a try. Under my room/speaker conditions they were not a good match. Doesn't mean they won't do it for you.