20 of 26Image
The speaker is loud and clear on the Thunderbolt, but you have to pull out the kickstand to hear the full effects.
HTC didn't think too much about the kickstand and microUSB placement so if you want to charge up your Thunderbolt, say while watching a movie, you will discover this doesn't work well with the kickstand.
There are some interesting bits under the battery cover including the four unknown gold dots just under the camera. The two leads in the upper left also connect with the gold part of the back cover inside.