I am a little confused as to why you are looking for HDMI speakers when I am fairly certain the Droid does not have HDMI. Connection methods that are available are USB (Through the USB-Micro Port), 3.5mm Headset Port, or Bluetooth. Now where I may be wrong is there may be a USB-Micro to HDMI adapter, but I highly doubt it. It also may not be possible to transmit audio over the USB cable as well.
That being said, your best options are likely a small set of high quality speakers that connect using the 3.5mm port or Bluetooth.