I'm running an Alpine MRP F-300 4 channel amp. 2 channels running factory speakers, 2 channels bridged to the sub. There is plenty of room for the speaker. I made the box a little taller than the jack cover. You can also put polyfill inside the box to make it seem larger. I like my set-up. I don't like brain rattling bass anymore, just nice rear fill and this works great for me. And my daughter doesn't complain about not having cup holders in the back anymore.