It feels like...

the sensation you get in your chest when you blow over an empty glass bottle, when I'm going it right. If there's too much breath pressure, the sound will wobble and get woolly sounding, and the core will be hidden or not even there. I'm still struggling with it, but this is the key. I know when it's right, and that's what it feels like when it is. I feel like my throat is open a little wider, too. Definitely a more relaxed sensation than when singing high, but not as relaxed as exhalation.