Question Why is the Carbon Cub FX-3 so deafening loud in the cockpit?

[Neal]

I remember back in my PPL days flying 152's and 172's not requiring hearing protection or even a headset, you could use the audio through the ceiling mounted speaker, although I did use a headset of some type. Now in the Carbon Cub FX-3 I'm amazed how loud it is in the cockpit. While I wear Bose A20's integrated into my former Air Force helmet, making it even more sound proof, it's not a big deal. But when flying my dog and her hearing protection slid off, I took off my headset to see how loud it was and was shocked, I air aborted to avoid causing my dog to go deaf. My Apple Watch often alerts on the sound levels.

Why is the FX-3 with IO-360 so incredibly loud in the cockpit?