Traduzindo o passo 13
The speakers are nice, but what makes them really sing are the fancy back volume chambers, machined directly into the unibody enclosure.
After removing the carbon fiber caps, we find the enclosures are filled with foam. Apple's own renders don't actually show this foam, but we're betting that it's used to amplify the effective volume of the enclosure.
That, or the stuffing indicates Apple got into the Thanksgiving spirit early this year.